Firing 4.5 inch rockets from M4-Sherman “Calliope” multiple rocket launcher, mounted on M-4, No. A-3 tank. 14th Armored, France.
T40/M17 mounted on M4 Sherman
While numerous rocket launcher mounts were developed for fitting to M4 series vehicles, very few saw operational use or reached production status.
Rocket Launcher T34 (Calliope): This consisted of 60 4·6in rocket tubes mounted in a frame above the turret. The two bottom sets of 12 tubes each could be jettisoned if necessary on all variants except the M4A1. The mount was traversed with the tank turret and elevated by a rod linked to the gun barrel. The Calliope was a “limited procurement” weapon, developed in 1943 and first used by 2nd Armored Division in France in August 1944. This weapon saw limited combat use until the end of the war.
The T34 Calliope Rocket Launcher was developed in 1943 and consisted of an array of sixty rocket tubes on a frame mounted above the turret of a Sherman tank. The tubes traversed with the turret and could be raised or lowered via a connecting rod to the gun barrel. The name came from its resemblance to the musical steam organ which has similar pipes. The T34 saw action with the US Army in 1944-45, firing 4.6-inch or 114-mm rockets, while the T34E2 saw this calibre increased to 7.2-inch or 183 mm.
Rocket Launcher T34E1: As T34 but with 14 tubes in two bottom projector units.
Rocket Launcher T34E2: Similar in appearance to the T34, but longer, the T34E2 held 60 7·2in rockets and the entire mount could be jettisoned if necessary in an emergency. This mount saw limited combat use, 1945.
Rocket Launcher T39: A mount of enclosed box construction with doors over the tubes. It held 20 7·2in rockets. Experimental only.
Rocket Launcher T40(M17) (Whiz-bang): This rocket launcher held 20 7·2in rockets in a box-like frame and was elevated hydraulically from the 75mm gun controls. The entire mount could be jettisoned if required, and the rockets could be fired singly or in salvoes. This “limited procurement” weapon was classified “limited standard” and saw some combat use in 1944-45.
Rocket Launcher T40 (short version): Experimental version of the above with shorter rocket tubes and 75mm gun removed and replaced by elevation mechanism for launcher. Access door for crew added in side of vehicle which was an M4A2.
Rocket Launcher T72: Similar to T34 but with very short tubes. Not used operationally.
Rocket Launcher T73: Similar to T40 but held only 10 rockets. Not used in combat. Experimental only on M4A1.
Rocker Launcher T76: This was a M4A1 with a 7 ½ in rocket tube replacing the 75mm gun. Had an opening in turret front around the mounting to allow gases to escape on firing. Reloaded from inside turret. Experimental only, 1944. Same weapon mounted on M4A3 HVSS was designated T76E1. Rocket Launcher
T105: A single 7·2in rocket projector in box-like case mounted in M4A1 in place of 75mm gun. Developed from T76, August 1945. Did not proceed past trials stage.
Multiple Rocket Launcher T99: Two small box-like launcher mounts, each holding 22 4·5in rockets, mounted each side of turret for vehicle with 76mm gun. Few produced 1945; also fitted experimentally to M26 heavy tank.
The German Army recognised the need for a more powerful form of anti-tank weapon and the design of a horse-drawn, 3.7 cm anti-tank gun (designated 3.7 cm Pak L/45) by Rheinmetall commenced in 1924 and the first guns were issued in 1928. However, by the early 1930s, it was apparent that horse-drawn artillery was obsolescent, and the gun was modified for motorized transport by substituting magnesium-alloy wheels with pneumatic tyres for the original spoked wooden wheels. Re-designated the 3.7 cm Pak 35/36, it began to replace the 3.7 Pak L/45 in 1934 and first appeared in combat in 1936 during the Spanish Civil War. It formed the basis for many other nations’ anti-tank guns during the first years of World War II. The KwK 36 L/45 was the same gun but adapted as the main armament on several tanks, most notably the early models of the Panzer III.
The Pak 36, being a small-calibre weapon, was outdated by the May 1940 Western Campaign, and crews found them inadequate against allied tanks like the British Mk.II Matilda, and the French Char B1 and Somua S35. Still, the gun was effective against the most common light tanks, such as the Renault FT-17 and saw wide service during the Battle of France and the T-26 during Operation Barbarossa. The widespread introduction of medium tanks quickly erased the gun’s effectiveness; miserable performance against the T-34 on the Eastern Front led to the Pak 36 being derisively dubbed the “Door Knocker” (Heeresanklopfgerät, literally “army door-knocking device”) for its inability to do anything other than advertise its presence to a T-34 by futilely bouncing rounds off its armor.
Not surprisingly The Pak 36 began to be replaced by the new 5 cm Pak 38 in mid 1940. The addition of tungsten-core shells (Pzgr. 40) added slightly to the armour penetration of the Pak 36. Despite its continued impotence against the T-34, it remained the standard anti-tank weapon for many units until 1942. It was discovered that Pak 36 crews could still achieve kills on T-34s, but this rare feat required tungsten-cored armour piercing ammunition and a direct shot to the rear or side armour from point-blank range.
As the Pak 36 was gradually replaced, many were removed from their carriages and added to SdKfz 251 halftracks to be used as light anti-armour support. The guns were also passed on to the forces of Germany’s allies fighting on the Eastern Front, such as the 3rd and 4th Romanian Army. This proved particularly disastrous during the Soviet encirclement (Operation Uranus) at the Battle of Stalingrad when these Romanian forces were targeted to bear the main Soviet armoured thrust. The Pak 36 also served with the armies of Finland (notably during the defence of Suomussalmi), it was also deployed in Hungary, and Slovakia.
In 1943, the introduction of the Stielgranate 41 shaped charge meant that the Pak 36 could now penetrate any armour, although the low velocity of the projectile limited its range. The Pak 36s, together with the new shaped charges, were issued to Fallschirmjäger units and other light troops. The gun’s light weight meant that it could be easily moved by hand, and this mobility made it ideal for their purpose.
The replacement for the outdated Pak 36 was the 50cm Pak 38. The longer barrel and larger projectile produced the required level of kinetic energy to pierce armour . The PaK 38 was first used by the German forces during the Second World War in April 1941. When the Germans faced Soviet tanks in 1941 during Operation Barbarossa, the PaK 38 was one of the few early guns capable of effectively penetrating the 45 mm (1.8 in) armor of the formidable T-34. Additionally, the gun was also equipped with Panzergranate 40 APCR projectiles which had a hard tungsten core, in an attempt to penetrate the armor of the heavier KV-1 tank. Although it was soon replaced by more powerful weapons, the Pak 38 remained a potent and useful weapon and remained in service with the Wehrmacht until the end of the war.
The 7.5 cm PaK 40 (7.5 cm Panzerabwehrkanone 40) was the next generation of anti-tank gun to see service. This German 7.5 centimetre high velocity anti-tank gun was developed in 1939-1941 by Rheinmetall and used extensively from 1942-1945 during the Second World War. It was the PaK 40 which formed the backbone of German anti-tank guns for the latter part of World War II. Development of the PaK 40 began in 1939 with development contracts being placed with Krupp and Rheinmetall to develop a 7.5 cm anti-tank gun. Priority of the project was initially low, but Operation Barbarossa in 1941 and the sudden appearance of heavily armoured Soviet tanks like the T-34 and KV-1, increased the priority. The first pre-production guns were delivered in November 1941.
In April 1942, Wehrmacht had 44 guns in service. It was remarkably successful weapon and by 1943 the PaK 40 formed the bulk of the German anti-tank artillery.The PaK 40 was the standard German anti-tank gun until the end of the war, and was supplied by Germany to its allies. Some captured guns were used by the Red Army. After the end of the war the PaK 40 remained in service in several European armies, including Albania, Bulgaria, Czechoslovakia, Finland, Norway, Hungary and Romania.
Around 23,500 PaK 40 were produced, and about 6,000 more were used to arm tank destroyers. The unit manufacturing cost amounted to 2200 man-hours at a cost of 12000 RM. A lighter automatic version, the heaviest of the Bordkanone series of heavy calibre aircraft ordnance as the BK 7,5 was used in the Henschel Hs129 aircraft.
The Pak 40 was effective against almost every Allied tank until the end of the war. However, the PaK 40 was much heavier than the 50 cm PaK 38, It was difficult to manhandle into position and its mobility was limited. It was difficult or impossible to move without an artillery tractor on boggy ground.
The PaK 40 debuted in Russia where it was needed to combat the newest Soviet tanks there. It was designed to fire the same low-capacity APCBC, HE and HL projectiles which had been standardized for usage in the long barreled Kampfwagenkanone KwK 40 main battle tank-mounted guns. In addition there was an APCR shot for the PaK 40, a munition which eventually became very scarce.
The main differences amongst the rounds fired by 75 mm German guns were in the length and shape of the cartridge cases for the PaK 40. The 7.5 cm KwK (tank) fixed cartridge case is twice the length of the 7.5 cm KwK 37 (short barrelled 75 mm), and the 7.5 cm PaK 40 cartridge is a third longer than the 7.5 cm KwK 40.
The longer cartridge case allowed a larger charge to be used and a higher velocity for the Armour Piercing Capped Ballistic Cap round to be achieved. The muzzle velocity was about 790 m/s (2,600 ft/s) as opposed to 750 m/s (2,500 ft/s) for the KwK 40 L/43. This velocity was available for about one year after the weapon’s introduction. Around the same time, the Panzer IVs 7.5 cm KwK 40 L/43 gun and the nearly identical Sturmkanone (StuK) 40 L/43 began to be upgraded with barrels that were 48 calibers long, or L/48, which remained the standard for them until the end of the war.
In the field, an alarming number of L/48 cartridge cases carrying the hotter charge failed to be ejected properly from the weapon’s semi-automatic breech, even on the first shot (in vehicles). Rather than re-engineer the case, German Ordnance reduced the charge loading until the problem went away. The new charge brought the muzzle velocity down to 750 m/s, or about 10 m/s higher than the original L/43 version of the weapon. Considering the average variability in large round velocities from a given gun, this is virtually negligible in effect. The first formal documentation of this decision appears on May 15, 1943 (“7.5cm Sturmkanone 40 Beschreibung”) which details a side by side comparison of the L/43 and the L/48 weapons. The synopsis provided indicates very little difference in the guns, meaning the upgrade had little if any benefit.
All further official presentations of the KwK 40 L/48 ( “Oberkommando des Heeres, Durchschlagsleistungen panzerbrechender Waffen”) indicate a muzzle velocity of 750 m/s for the gun. As for the PaK 40, the desire for commonality again appears to have prevailed since the APCBC charge was reduced to 750 m/s, even though case ejection failures apparently were never a problem in the PaK version of the gun.
For reasons which seem to be lost to history, at least some 75 mm APCBC cartridges appear to have received a charge which produced a muzzle velocity of about 770 m/s (2,500 ft/s). The first documented firing by the U.S. of a PaK 40 recorded an average muzzle velocity of 776 m/s for its nine most instrumented firings. Probably because of these results, period intelligence publications (“Handbook on German Military Forces”) gave ~770 m/s as the PaK 40 APCBC muzzle velocity, although post war pubs corrected this (Department of the Army Pamphlet No. 30-4-4, “Foreign Military Weapons and Equipment (U) Vol. 1 Artillery (U) dated August of 1955-this document was originally classified).
In addition, German sources are contradictory in that the Official Firing Table document for the 75 mm KwK 40, StuK 40, and the PaK 40 dated October, 1943 cites 770 m/s on one of the APCBC tables therein, showing some confusion. (“Schusstafel fur die 7.5cm Kampfwagenkanone 40”).
The 88 mm gun (eighty-eight) was a German anti-aircraft and anti-tank artillery gun from World War II. It was widely used by Germany throughout the war, and was one of the most recognized German weapons of the war. Development of the original models led to a wide variety of guns.
The name applies to a series of guns, the first one officially called the 8,8 cm Flak 18, the improved 8,8 cm Flak 36, and later the 8,8 cm Flak 37. Flak is a contraction of German Flugzeugabwehrkanone meaning “anti-aircraft cannon”, the original purpose of the eighty-eight. In informal German use, the guns were universally known as the Acht-acht (“eight-eight”), a contraction of Acht-komma-acht Zentimeter (“8.8 cm”). In English, “flak” became a generic term for ground anti-aircraft fire.
The versatile carriage allowed the eighty-eight to be fired in a limited anti-tank mode when still on wheels, and to be completely emplaced in only two-and-a-half minutes. Its successful use as an improvised anti-tank gun led to the development of a tank gun based upon it. These related guns served as the main armament of tanks such as the Tiger I: the 8.8 cm KwK 36, with the “KwK” abbreviation standing for KampfwagenKanone (“fighting vehicle cannon”).
In addition to these Krupp’s designs, Rheinmetall created later a more powerful anti-aircraft gun, the 8,8 cm Flak 41, produced in relatively small numbers. Krupp responded with another prototype of the long-barreled 88 mm gun, which was further developed into the anti-tank and tank destroyer 8.8 cm Pak 43 gun, and turret-mounted 8.8 cm KwK 43 heavy tank gun.
At the outbreak of war the artillery equipment of the Wehrmacht was standardised on a few calibres, and the weapons were in general of sound and well-tested design. The army’s field weapons were of 10.5cm, 15cm and 21cm calibres, and the design philosophy ensured that a gun of given calibre and a howitzer of the next larger calibre were interchangeable on the same carriage, thus simplifying production, supply and maintenance. Anti-aircraft defence was built around the 2cm and 3.7cm light guns, the 8.8cm medium gun and the 10.5cm heavy gun; anti-tank weapons were the 3.7cm gun and a 7.92mm anti-tank rifle for infantry use. One or two improved designs were undergoing routine development with the intention of bringing them into service as and when the need arose.
The demands of war soon spoiled this arrangement. When it came to forecasting the future, the OKW was no more visionary than any other comparable body and the appearance of new weapons in the hands of the enemy frequently led to sudden demands on designers to develop powerful antidotes. An example of this was the sudden flurry of activity in the anti-tank field consequent upon the appearance of the virtually unstoppable Soviet T34 tank. The users’ demands on the gunmakers were always the same: improve the performance of the gun, increase its range, increase its velocity, but please do not increase its weight. How these demands were translated into reality will be seen on subsequent pages but, as a general rule, the paths open to the designers were well-defined. The only way to improve the performance of a conventional gun is by increasing the muzzle velocity, and this can be done m a variety of ways.
The first and most simple technique is to increase the size of the propelling charge or to develop a more efficient propellant, while still operating the gun at the same pressure. This, in round figures, demands a four-fold increase in propellant quantity to obtain a 60% increase in muzzle velocity, and contains several disadvantages in the shape of erosive wear, redesign of the chamber and cartridge case, and economic production of the propellant.
The second simple method is to increase the length of the barrel, thus keeping the projectile exposed to the accelerating effect of the exploding propellant for a longer time. To obtain the 60% increase in velocity would demand a 300% increase in barrel length-scarcely a practical measure.
An increase in chamber pressure combined with a moderate increase in barrel length will also increase velocity. The standard 60% increase could thus be achieved by a 50% increase in pressure coupled to a 50% increase in barrel length, but again this is scarcely a practical answer. One solution, increasingly adopted by many nations towards the end of the war, was a 50% reduction of projectile weight which increased the velocity by 40%- but the ballistic coefficient (the `carrying power’ of the projectile) was proportionately reduced. Deceleration in flight was hence more rapid, leading to less range than a full-weight projectile would have achieved at the same velocity.
Owing to these conventional design limitations, the war initiated the examination of more and more unconventional solutions. One of the first, which had been developed well before the war, was the production of high-velocity guns in which the rifling consisted of a few deep grooves into which fitted curved ribs on the outer surface of the shell, imparting positive rotation. This was developed because the conventional copper driving band was incapable of transmitting the enormous torque of high velocity projectiles’ excessive radial acceleration without shearing. The ribbed or `splined’ shell solved the problem of transmitting spin, but a copper band still had to be fitted to provide the gas-seal necessary at the rear of the shell. This was an expensive and complicated solution, suited only to large weapons produced in limited numbers, and much research was begun to try and overcome the torque defect of the copper driving band, with the additional incentive of trying to find a material in less critical supply.
The first development was the Krupp Sparführung (KpS) band-a bimetallic band of copper and soft iron, although zinc was sometimes added to dilute the copper and to assist in effecting the iron/copper joint. There was little or no performance advantage, merely an economy of copper. Next came the Weicheisen (FeW) soft iron band, the use of which was restricted to large calibre high-velocity guns. It could withstand torque very well, but the process of putting the band on the shell (by a powerful radial press) work-hardened the metal to the point where it became difficult to `engrave’-or force into the gun’s rifling. It was this defect that restricted Weicheisen bands’ use to high-pressure large-calibre weapons.
The final development was the Sintereisen (FeS) wintered iron band, formed from small iron particles bonded together under intense pressure to form a malleable band. This engraved well, resisted shear stresses, and was economical of material in short supply, but in its first application was found to wear out the gun barrels faster than a conventional copper band. Further development evolved a new form of barrel rifling with wider lands and grooves, and this-together with the reintroduction of increasing twist-improved matters to a degree where the German technicians opined that even if they had sufficient copper available they would still prefer to use sintered iron, particularly at higher velocities. One interesting result was the discovery that, while copper bands resulted in the gun barrel wearing out first at the chamber end of the rifling, FeS bands promoted wear at the muzzle since the coefficient of friction was directly proportional to the velocity.
When the increases in performance made available by increasing the barrel length and the size of the charge, and the provision of improved rifling and banding, had been taken to their extremes, it became necessary to explore less well-trodden paths. The first unorthodox solution offered was the `coned bore’ gun, the theory of which predicated that if the barrel was made with a gradually-decreasing calibre (and if the projectile was designed to adapt to the diminution) then, since the base area of the shot is reducing while the propelling gas pressure either remains-depending on the cartridge design-constant or increases then the unit pressure on the shot base will increase and the shot will be given greater velocity. The original idea was patented in 1903 by Carl Puff and the drawings accompanying the specification (British Patent 8601 of 27th August 1904) show a projectile almost identical to those later developed in Germany. Puff, however, does not appear to have pursued his ideas as far as a working gun, and the idea lay dormant until taken up by a German engineer named Gerlich in the 1920s. In co-operation with Halbe, a gunmaker, he developed a number of high-velocity sporting rifles with tapered bores and flanged projectiles, marketed in limited numbers during the 1930s under the name Halger, while at the same time attempting to interest various governments in the possible use of these weapons as high velocity military rifles. He also worked for both the United States’ government and the British Army on taper-bore rifles, but neither felt that there was much virtue in the idea; Gerlich returned to Germany c. 1935, and his subsequent activities have escaped record.
By this time others were exploring the idea: Rheinmetall-Borsig, Krupp, Bochumer Verein and Polte-Werke all had experimental programmes varying in degree of involvement. Rheinmetall-Borsig eventually became the most involved; the firm’s Dr Werner Banck, who took charge of development in late 1939, continued to work on it throughout the war and ultimately became one of the most knowledgeable men in the world on the subject of taper-bore guns.
The 75/55-mm tapered bore 7.5-cm Pak 41.
Two classes of weapon were eventually categorised: the taper bore, in which the barrel tapered evenly from breech to muzzle, and the squeeze bore, in which the barrel was parallel for some distance and then tapered sharply to effect the `squeezing’ of the projectile, finishing as a parallel bore of smaller dimension. An alternative design of squeeze bore was one in which a tapered extension was placed on the muzzle of an otherwise conventional gun. The projectiles used with these two classes were much the same in design, though experience showed that the taper bore shot had to be somewhat stronger in construction than the squeeze bore models owing to the different times throughout which the shells underwent stress in compression.
Towards the end of the war the taper bore concept was gradually discarded in favour of the squeeze bore designs, since these were a good deal easier to manufacture. Making a tapered and rifled gun barrel was no easy task, even with sophisticated machine tools, whereas production of a smoothbore `squeeze’ extension to fit the muzzle of an otherwise standard gun was much less exacting and less wasteful of time and material. Weapons as large as 24cm calibre were fitted with such extensions (in this case reducing to 21cm) and were fired quite successfully.
The only active-service use of the taper or squeeze systems was in the anti-tank class, where three weapons (2.8cm/2.1cm, 4.2cm/2.8cm and 7.5/5.0cm) entered service. In the anti-aircraft field, while the velocity increases gave promise of considerably improved performance and where many experimental weapons were built and fired, no guns were ready for service before the war ended. There was a rule of thumb that said a squeeze bore adaptor could be expected to increase velocity and maximum range by about a third. Velocities of as much as 1400mps (4595fps) had been achieved but it was felt that, bearing in mind wear-rates and dispersion at extreme ranges, service velocities of 1150-1200mps(3775- 3935fps) might be consistently reached.
Successive Royal Navy post-Dreadnought classes were basically improved versions of that pioneering warship. The next significant advance came with the Orions (Orion, Conqueror, Monarch, and Thunderer, constructed between 1909 and 1912). They were improvements over previous designs and were promptly called super dreadnoughts. Their new 13.5-inch guns gave considerably increased firepower for a small addition in weight and size; range was increased to a spectacular 24,000 yards. The Orions’ main batteries were arranged on a pattern pioneered by the U. S. Navy that would prevail until the last battleship was designed: All turrets were mounted on the centerline, and fore-and-aft turrets were superimposed one on the other, a vast improvement on the German and previous RN wing turrets. The Orions’ armor was extended up to the main deck, eliminating a major weakness of the early dreadnought classes. Still, they suffered from the same lack of beam, which gave inferior underwater protection compared to the German ships. The unsound British argument was that greater beam made the ship more unsteady and reduced speed. The Orions, as noted, were also the last RN dreadnoughts to position their firing platforms directly abaft the forward funnel.
The next major advances in battleship design were seen in the five impressive Queen Elizabeths (Queen Elizabeth, Valiant, Barham, Malaya, and Warspite, completed in 1915-1916). Well ahead of anything the German Navy would produce, they were confidently designed to outrace a retreating enemy fleet. The Queen Elizabeths were the world’s first large oil-burning warships. The Admiralty knew full well that the Germans would be unlikely to go over to oil-burning entirely, as the Germans, unlike the British, were presumed to lack an assured oil supply in wartime. (Of course, with their penchant for invading other countries, the Germans might have been expected to take over Romania’s oil fields, which is what they later did in World War I.) Also, oil gave considerably greater thermal efficiency, discharged much less smoke, and released all personnel from the filthy, time-consuming bondage of coaling. Oiling was simply a matter of running out hoses and opening valves. Thus Great Britain, with no domestic oil resources of its own, had given hostages to the world’s petroleum producers.
The Queen Elizabeths were also the first to mount 15-inch main battery guns, and all five units fired those guns at Jutland. They and two units of the following Revenge class (Revenge, Royal Oak, Ramillies, Resolution, and Royal Sovereign, completed 1916-1917) were the last RN battleship class to fight in World War I and, with the Elizabeths, were the only capital ships of any naval power to use their main guns against enemy battleships in both world wars. (Three more units, Renown, Repulse, and Resistance, were suspended, then canceled in 1914 at the outbreak of war.)
The dreadnought was easily the most expensive weapon of World War I. By contrast, the most costly war tool of World War II (1939-1945) was the U. S. Army Air Force’s B-29 Superfortress heavy bomber. Obviously, the battleship’s status had considerably depreciated since 1918; not one battleship was laid down and completed during World War II.
Yet paradoxically, there were considerably more battleship-to-battleship clashes in World War II than in World War I, although, as in World War I, there would be only one large fleet battleship action. Yet despite their diminished role in World War II, roughly the same number of battleships would be lost as in World War I (23 versus 25, including self-scuttlings).
Like the other naval powers, all battleship-oriented, the Royal Navy entered World War II with a collection of World War I-era battleships, modernized and unmodernized, and with new battleships on the way. It also had the only battleships in any navy designed and completed during the 1920s, Nelson and Rodney. Except for the Nelson class, the Royal Navy during World War II would lose one each from its other battleship classes, in all losing three battleships: Royal Oak, Prince of Wales, and Barham. The oldest of the Royal Navy’s battleships serving in World War II were the five Queen Elizabeths. Of them, Valiant, Warspite, and Queen Elizabeth had been given the most complete reconstructions of any RN battleship. The unmodernized Barham would be lost to submarine torpedo, taking 862 crewmembers, in 1941. Later came the five Royal Sovereigns, of which Royal Oak was lost in Scapa Flow, with 786 dead, in 1939, again to a German submarine torpedo. These later but cheaper warships were not as highly valued as the Queen Elizabeths, perhaps because they were slower and they did not undergo nearly as extensive a modernization. In fact, the Admiralty seriously considered expending two of this class as blockade ships off the German coast. One, Royal Sovereign, was loaned to the Red Fleet for the war’s duration.
The newest RN battleships of World War II were the King George V class (King George V, Prince of Wales, Duke of York, Anson, and Howe, not to be confused with the King George V class of 1911-1912). Again, one unit of this class, Prince of Wales, was lost during the war, this time to aerial attack by the Japanese in December 1941. The class was severely criticized for its 14-inch main guns. This retrograde decision (after all, the considerably older Nelson and Rodney boasted 16- inch guns) was made in order to get at least the first two units of the class completed in 1940, by which date conflict with Germany was expected. As it was, only King George V was ready for service in 1940. Like the Nelson class, the King George V class had significant maingun mounting problems. Nonetheless, the Royal Navy generally felt that the class gave good value for the money.
A follow-on class, the Lions, was designed to mount 16-inch guns, but the realities of World War II saw to it that these battleships did not get past the laying-down stage, if that. Even so, as late as 1943-1944, there was actually a brief flurry of interest in completing the Lions, which went nowhere. Two years into World War II, Great Britain laid down HMS Vanguard as a mount for the never-installed 15-inch guns of the freak giant battle cruisers Glorious and Courageous, long since converted to aircraft carriers. Vanguard was basically Winston Churchill’s idea (the prime minister always had a soft spot for battleships) and was supposed to reinforce the RN fleet at Singapore. But long before Vanguard was launched in 1944, the Singapore bastion had fallen ignominiously, and Prince of Wales (along with the battle cruiser Repulse) had been lost to Japanese airpower off Malaya. Work proceeded very slowly during the war on Vanguard, the largest and last British battleship ever built; it was not completed until 1946, never fired a shot in anger, and was scrapped in 1960.
The cancellation of the Lions and the slow pace of construction on Vanguard should not be taken as an indication that the Royal Navy had given up entirely on battleships. Incredibly, the First Sea Lord (i. e., the highest-ranking RN officer), Admiral Andrew Cunningham, in May 1944, well after Taranto, Pearl Harbor, and the loss of Prince of Wales and Repulse, argued that, for the postwar Royal Navy, “the basis of the strength of the fleet is in battleships and no scientific development is in sight which might render them obsolete” (quoted in Eliot A. Cohen, Supreme Command: Soldiers, Statesmen, and Leadership in Wartime, New York: The Free Press, 2002, pp. 121-122). Admiral Cunningham was no armchair theoretical navalist, but probably the best admiral the Royal Navy produced during World War II. Yet by the time Cunningham made his lamentable projection, the Royal Navy had ceased all battleship construction except for its leisurely work on Vanguard; after World War II it would lose no time in scrapping all its surviving battleships (except for Vanguard).
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REPORT ON EVENTS WHICH OCCURRED IN 14in TURRETS
23rd TO 25th MAY
Friday, 23rd May
A – Events prior to First Action
The order to load the cages was given late in the afternoon. In the course of loading the following defects developed:-
No. 2 gun loading cage: Front flashdoors could not be opened fully from the transverser compartment and the cage could not be loaded. Examination showed that the front casing had been badly burred by being struck by the lugs carrying the guide rollers on the gun loading rammer head when the latter was making a “withdrawing” stroke.
This was cleared by filing and the other gun loading cages were examined for the same defect. Slight burring was found in some cases and was dressed away.
No. 1 gun: On ramming shell the second time after the order “Load”, the shell arrestor at the shell ring level jammed out and could not be freed before the first action.
While steaming at high speed, large quantities of sea water entered “A” turret round the gun ports and through the joints of the gunhouse roof. It became necessary to rig canvas screens in the transverser space and bale the compartment.
No. 2 central ammunition hoist: Arrestor at shell ring level would not withdraw after ramming shell. It is impossible to strip this in place in the Mark II mounting, and the arrestor was removed complete. The axis pin of the pinion driving the inner tube of the arrestor had seized. There does not appear to be any effective means of lubricating this pin. The pin was drilled out and removed and the arrestor re-assembled. It was not, however, possible to replace the arrestor before action stations was ordered, because at this stage a defect developed in the hinge trays of the forward shell room as described below. This latter defect was taken in hand immediately in order to free the revolving shell ring and was completed a few minutes after action stations. It was not then considered advisable to proceed with replacing the arrestor.
Hinge trays at forward shell room fouled the locking bolt on the revolving shell ring: both trays being bent.
Saturday, 24th May
During the early hours hydraulic pressure failed on the revolving shell ring ship control in “B” turret. This was due to the pressure supply to the turret from the starboard side of the ring main being isolated. The revolving shell ring ship control is fed from the starboard side only, and the non-return valves on the pressure main adjacent to the centre pivot prevent pressure being fed to the starboard side and the revolving shell ring ship control from the port side in the event of the former being isolated from the ring main. Similar conditions exist on the port side of “A” and the starboard side of “Y”. It is considered essential that a cross connection be fitted in the shell handling room with two non-return valves so that the revolving shell ring ship control can be supplied from either side of the ring main.
B – Events during the First Action
The following defects developed in “A” turret:-
On several occasions the shell ring rammers fouled the brackets on the hinge trays for No. 11 interlock. Shell could not be rammed until the bearing of the turret was changed. This also occurred in “Y” but did not prevent ramming.
No. 1 gun only fired one salvo, due to the events described in A (i).
After the second salvo, No. 24A interlock failed on No. 2 shell ring rammer. It was tripped after a short delay and thereafter assisted by hand.
About halfway through the firing, the tappets operating the shell ring arrestor release gear on No. 4 rammer failed to release the arrestor. Subsequent examination has shown that the shaft carrying the levers operating these tappets had twisted. The rammer was kept in action by giving the tappets a heavy blow at each stroke.
Shortly after this, a further defect occurred on No. 4 shell room rammer. When fully withdrawn the rammer failed to clear No. 7 interlock and the ring could not be locked. This was overcome by operating the gear with a pinch-bar at every stroke.
Throughout the engagement the conditions in “A” shell handling room were very bad; water was pouring down from the upper part of the mounting. Only one drain is fitted and became choked; with the result that water accumulated and washed from side to side as the ship rolled. The streams above and floods below drenched the machinery and caused discomfort to the personnel. More drains should be fitted in the shell handling room and consideration given to a system of water catchment combined with improved drainage in the upper parts of the revolving structure. Every effort is being made to improve the pressure systems and further attempts will be made as soon as opportunity occurs to improve the mantlet weathering, but a certain amount of leaking is inevitable.
No mechanical defects.
The following defects occurred in “Y” turret:-
Salvo 11 – No. 3 central ammunition hoist was raised with shell but no cordite; No. 25 interlock having failed to prevent this. The interlock was functioning correctly before the engagement. There has been no opportunity to investigate this. It is also reported that the reason no cordite had been rammed was that the indicator in the cordite handling room did not show that the cage had been raised after the previous ramming stroke. This caused the gun to miss salvoes 15 to 20.
Salvo 12 – Front flashdoors of No. 2 gun loading cage failed to open and cage could not be loaded. Flashdoors on transfer tubes were working correctly and investigation showed that adjustment was required on the vertical rod operating the palm levers which open the gun loading cage doors. To make this adjustment, three-quarter inch thread had to be cut on the rod. This defect was put in hand after the engagement had been broken off and was completed by 1300. It would appear that the operating gear had been strained, possibly by the foreign matter in the flashdoor casing making the doors tight. The doors were free when tried in the course of making the repair. This caused the gun to miss salvo 14 onwards.
Salvo 20 – Owing to the motion of the ship, a shell slid out of the port shell room and fouled the revolving shell ring while the latter was locked to the trunk and the turret was training. The hinge tray was severely buckled, putting the revolving shell ring out of action. The tray was removed, but on testing the ring it was found that No. 3 and 4 hinge trays of the starboard shell room had also been buckled and were fouling the ring. The cause of this is not yet known. The trays were removed and as the action had stopped by this time, No. 4 tray was dressed up and replaced. The ring was out of action until 0825.
C – Events subsequent to First Action
During the day in “A” turret, No. 1 central ammunition hoist shell arrestor was driven back with the intention of carrying on without it by ramming cautiously. The gun and cages were then loaded, but owing to the motion of the ship the round in the central ammunition hoist cage slid forward until its nose entered the arrestor, putting the hoist out of action again. Subsequent examination has shown that the anti-surging gear in this cage was stiff and consequently did not re-assert itself after ramming to traverser.
D – Events during the Second Action
No. 1 gun fired only two salvoes owing to central ammunition hoist being out of action as described above in C, para 1. At salvo 9, No. 3 central ammunition hoist shell arrestor jammed out.
“B” and “Y” Turret
E – Events subsequent to Second Action
No. 3 central ammunition hoist shell arrestor was removed complete from the hoist. Time did not allow of it being stripped and made good, but it was intended to use the hoist without it. The gun and cages were loaded in this manner.
F – Third Action
First Salvo – Shell rammed short into No. 3 central ammunition hoist cage. In trying to remedy this a double ram was made, putting the shell ring out of action. The second shell was hauled back by tackle, clearing the ring. The base of the shell in the central ammunition hoist cage was jamming against the upper edge of the opening in the hoist. This could not be cleared as the central ammunition hoist control lever cold not be put to lower. After much stripping the trouble was located in a link in the control gear which was found to be out of line.
G – General
With pressure being kept on shell room machinery for a long period, much water has accumulated in the shell rooms and bins. Suctions are fitted from 350-tomnm pumps only and these are not satisfactory for dealing with relatively small quantities of water. Drains are urgently required. It is suggested that a drain be fitted at each end of each shell room and larger drain holes be made in the bins; present drain holes being quite inadequate and easily choked.
The drains should be led to the inner bottom under the cordite handling room. Non-return valves and flash-seals could be fitted if considered necessary.
On passage to Rosyth after the action, two further hinge trays in “Y” shell handling room were buckled by fouling the revolving shell ring.
The official approval of the Armstrong 40-pounder RBL gun included this drawing which gave details of the gun sights and breech vent-piece.
Originally trained as a lawyer, Sir William George Armstrong (1810-1900) turned his talents to engineering, inventing hydraulic engines and cranes. In 1854 he patented a wrought iron rifled cannon that incorporated a number of graduated reinforcing bands, giving it a distinctive stepped profile. Armstrong also developed a unique “shunt” type of rifling, with each groove cut to two depths to accommodate the system’s special studded projectiles. The deeper half of the groove provided extra space to ease loading, whereas, upon firing, the studs shifted to the shallow side to provide the close fit within the bore necessary for accuracy. The powder charge was contained in a separate bag. The breech mechanism consisted of a separate wrought iron vent piece that was inserted into a slot in the top of the piece and locked into position by way of a large screw in the rear of the gun. A copper ring in the face of the vent piece expanded on firing to seal the breech and prevent the escape of gasses and subsequent loss of energy.
In July 1855, Armstrong submitted a 3-pounder breechloader for tests to the master general of the ordnance, and after a series of trials against other designs a special committee approved it for the British service on 16 November 1858. Upon the acceptance of his design, Armstrong relinquished all patent rights to the Crown and was subsequently appointed superintendent of the Royal Gun Factory at Woolwich in November 1859. By March 1861, Armstrong had overseen the manufacture of 941 of his guns for the British army, as well as guns for the Royal Navy. The most popular Armstrong for field use, the 3-inch 12-pounder, had a range of some 2,200 yards. One of the more long-lived Armstrongs, the Model 1862 “Pattern G” 40-pounder, remained in service until 1920. Production of the Pattern G totaled some 810 guns. The 70-pounder 6.4-inch breechloading Armstrong fired a 79.8- pound projectile loaded with a 5.4-pound bursting charge 2,183 yards. Examples of large 8.5-inch (150-pounder) 120-inch-long muzzle loading Armstrongs weighed up to about 15,790 pounds and required a 20-pound charge.
Armstrong Model 1862 “Pattern G” 40-pounder
A number of different carriages for guns employed for Land Service were available. A wooden siege carriage with wheels and attached limbers, enabled the guns to be drawn by teams of heavy horses.
For guns mounted in fortifications they could be mounted on two different types of carriage. The first was an iron traversing carriage, enabling the gun to be traversed right and left, with recoil being absorbed with a carriage being mounted on a slide. Others were mounted on high “siege travelling carriages” for use as semi-mobile guns in forts, firing over parapets.
Many were re-issued to Volunteer Artillery Batteries of Position from 1889, with 40 Pounders among 226 guns issued to the Volunteer Artillery during 1888 and 1889. The 1893 the War Office Mobilisation Scheme shows the allocation of thirty Artillery Volunteer position batteries equipped with 40 Pounder guns which would be concentrated in Surrey and Essex in the event of mobilisation. They remained in use in this role until 1902 when they were gradually replaced by 4.7-inch Quick Firing (QF) guns. A number were used for some years afterwards as saluting guns.
Designer W.G. Armstrong Co.
Manufacturer W.G. Armstrong Co.
Royal Gun Factory
Produced 1859 – 1863
No. built 1013
Variants 32cwt, 35cwt
Mass 32 cwt (3,584 pounds (1,626 kg)), later 35 cwt (3,920 pounds (1,780 kg)) gun & breech
Barrel length 106.3 inches (2.700 m) bore & chamber
Shell 40 pounds 2 ounces (18.20 kg)
Calibre 4.75-inch (120.6 mm)
Breech Armstrong screw with vertical sliding vent-piece (block)
On 1 November 1918 the Canadian Corps would take Valenciennes. The small city was only 30 kilometres from Le Cateau but the artillery tactics and techniques were four years apart, and it made a world of difference.
In late October Haig reckoned the Germans were on their last legs, with Turkey and Bulgaria knocked out of the war and Italy preparing to attack the tottering Austrians. With the Americans and French attacking, it was time for the BEF to launch one final blow. To get the British First Army in position for the anticipated Battle of the Scheldt, they first needed to take Valenciennes, which lay east of the Scheldt Canal. Because of the rain and German-controlled flooding, the low ground west of the canal was flooded for a distance of perhaps a thousand yards; in addition, there was barbed wire on the eastern bank and the German troops (and machine guns) were safely positioned in houses. A frontal assault across the canal was out of the question. However, the canal swung round the city and to the south XXII Corps had got across. If the Germans could be thrown off Mt Houy (which was only 150ft high, but about 50ft higher than the surrounding country-side, and blocking observation of German artillery to the east), they could be levered out of Valenciennes.
However, the Germans recognised the key ground and they had plenty of guns; in addition, troop morale was reasonably firm. From 24 to 28 October several British attacks were made, all rushed and poorly supported, more in hopes that the Germans were weak than in confidence that the attacks would succeed. But the British troops were at the limit of their supply lines (railheads were 30 miles back, and lorries were in short supply), casualties had thinned the ranks and everyone was tired. The Scots of the 51st (Highland) Division pushed up Mt Houy, but their last attack on 28 October was driven back from the crest by a German counter-attack, despite support from nine brigades of field artillery and fourteen batteries of heavies.
The Canadian Corps was now moved in to make the attack. The Canadians had been facing the canal, but since the main thrust could not be made there, they were available. The 4th Canadian Division relieved the 51st Highlanders, and moved up guns and shells; they took several days to plan their attack. Few infantry and plenty of support was a key element of their plan: ‘to pay the price of victory, so far as possible, in shells and not in the lives of men’. The delay also allowed time to coordinate infantry, machine guns and artillery. The Canadians knew there had been several failed efforts to take Mt Houy, and steadily increasing German artillery fire showed the enemy’s determination to hold the position; however, the Canadian gunners were just as determined to crush German resistance by weight of shell.
The attack would be some 2,500 yards wide (about 1½ miles). One Canadian infantry brigade would attack (by this stage of the war, that meant about 1,200 men). Generally speaking, about 10 per cent of any unit was left out of battle in case there were heavy casualties. For that one infantry brigade, there were eight brigades of field artillery and six of heavy artillery. The first objective was basically Mt Houy, and the second was 2,000 yards beyond it, clearing a few villages and the suburbs of Valenciennes.
There was no preliminary bombardment, but most of the heavy artillery fired well ahead of the infantry, hitting the German defence in depth and the reserves. No fewer than 39 6-inch howitzers were assigned to fire one round per minute over the front of the attack, a ratio that equated to 1.6 shells per 100 yards and the bursting radius was over 500 yards. McNaughton was putting ‘a practically continuous rain of chunks of steel across the whole front of the attack’. That was the first phase; when the Germans were pushed off Mt Houy and lost their observation posts there, more Canadian guns could fire, and the second phase of the attack narrowed to 1,000 yards. Some 55 howitzers would fire 2 rounds every 3 minutes, so it became 3.6 rounds per minute per 100 yards.
In all, 144 18-pounders and 48 4.5-inch howitzers would fire a creeping barrage (effectively 7 tons of shells per minute), deliberately moving at only 100 yards in four minutes (later slowing to five minutes) so that the infantry would have no problem keeping up. The field from the foremost howitzers would fire some smoke shells but would also hit selected strong-points ahead of the 18-pounders. The infantry, in turn, pulled back from the foremost positions on the lower slopes of Mt Houy so the artillery would have a straight (and convenient) line for its starting barrage. Machine guns fired both forward and flanking barrages, taking advantage of the topography: Mt Houy was an exposed salient. The infantry would be attacking from the southwest with machine guns firing from the south and heavy artillery firing from the north. Additional machine-gun and heavy artillery barrages were planned for the right flank of the attack, covering the ground with fire instead of sending more infantry into battle. Planning also took into account where German reserves were likely to be and thus where counter-attacks were likely to start. Since the towns and villages were full of refugees, the French had forbidden unnecessary shelling. (The Germans were continuing to use gas shells, and the Canadian troops were upset about its use around unprotected civilians; they were prone to confiscate gas-masks from German prisoners and give them to civilians. They were also taking relatively few prisoners at this stage in the war.) The Canadians decided only to hit counter-attacks on the edge of towns; this meant that the Germans had a good night’s sleep in a building but they were easier to kill in the open. The half-circle of British positions allowed enfilade fire not only on the front line but on roads (for harassing fire) and on reserves. Counter-battery work was not neglected, with 49 guns assigned to obliterate the 26 known German battery positions. The gunners slept by their guns in case the Germans got wind of the attack.
One battery was assigned a particularly devious mission. It was deliberately sited where it could fire into the rear of the German positions, and shortened its range as the attack progressed. Not only did this prevent it from hitting the Canadian infantry, but the Germans would think their own artillery was shelling them and their morale would suffer accordingly.
At dawn, 05.15 hrs, on All Saints’ Day the bombardment crashed out and the infantry moved forwards. German artillery fired promptly and accurately but mainly at the British artillery, with little or no effect. (Gibbs called it a ‘fierce line of fire’ but noted that it quickly ended as counter-battery fire took effect.) The hapless German infantry soldiers, meanwhile, were deluged with shell-fire. Gibbs wrote, ‘our barrage rolled like a tide wiping them off the map of France’, and the New York Times headlined the story ‘British Gunfire Paralyses Foe’. Prisoners, ‘stupefied and demoralised’, surrendered freely, including a complete company that was trapped in the fog and smoke; perhaps the first thing they saw of the Canadians was their bayonet points. With these advantages, the first objective was reached on time. A few machine-gun nests and a single field gun held out during the advance to the second objective, inflicting casualties before being overrun by the experienced infantry. The heavy artillery fire stayed ahead of the barrage and deliberately smashed some rows of houses where the Germans were known to have positions (any refugees killed here were regarded as collateral damage). Once the objectives were secured, it was time to see what the Germans would do. Each of the infantry battalions moved a 6-inch trench mortar forwards, and three brigades of field artillery moved on to the slopes of Mt Houy. Their observers moved to the top, so they could quickly engage any target they saw. Shortly after noon German infantry was seen forming up and the planned protective barrage was employed: 11 batteries of 6-inch howitzers rolled a barrage over the Germans. The survivors lost all interest in attacking. Between 15.00 and 16.00 hrs more movement was seen on the right flank, and on-the-fly plans were made to hit the Germans once they had fully formed up. At 16.35 hrs the situation was judged ripe, and 9 batteries of 6-inch howitzers obliterated another counter-attack.
The results were gratifying. Mt Houy was taken and the Germans were levered out of Valenciennes. (Another Canadian brigade had squelched forwards to the canal to test the German positions, and found almost no resistance. By mid-morning two Canadian battalions were solidly across. The German infantry had withdrawn very quickly, probably realising from the noise of the bombardment on their left rear flank that their comrades could not hold under such a maelstrom.) Over 800 dead Germans were found around Mt Houy alone, and 1,800 prisoners taken. The 2,149 tons of shells had done their work. But the Canadians also suffered 501 casualties, out of the 1, 200 infantry in the attack. Massive (and well handled) firepower could reduce casualties – not least by allowing fewer infantry to attack – but there was no avoiding a substantial percentage of casualties. The three British divisions attacking further to the south took over 1,600 prisoners and counted 300 dead; their casualties were higher than the Canadians’, but by this stage of the war a well supported Allied attack could easily break any German line. The Canadians had used every trick in the Allied arsenal and noted a number of ideas for the future but their brutally effective use of artillery had not solved all the problems of the Great War.
The 38cm S.K. L/45 ‘Max’ was Germany’s largest-calibre railway gun. It could fire from the rails as a rolling mount, but only when the barrel was elevated less than 18 degrees. This gun was captured by the Belgian Army.
For long-range fires the German 38cm S.K. L/45 ‘Max’ operated from a fixed ground platform. Here, the carriage is raised on its jacks with the rear bogies removed. After the front bogies are taken away, the crew will lower the carriage and bolt it to the platform.
German Turntable Mount for 38cm S.K. L/45 ‘Max’. German firing platforms permitted railway guns to rotate on the mount, providing a wide field of fire and, in some cases, all-around fire. The most sophisticated of these mounts was a structural steel turntable mount built for the 38cm S.K. L/45 ‘Max’ and later used by the 21cm Paris Gun. Because nearly three weeks were needed for installation, the platforms were constructed well before a railway gun arrived at the position.
In the winter of 1917–18, Krupp built several new models of E.u.B. railway guns for the German Army’s upcoming spring offensives. Most of the barrels used for the guns came from fixed platform artillery or decommissioned warships. Four 24cm K. L/30 ‘Theodor Otto’ guns were made by mounting old 24cm cannons onto the ‘Theodor Karl’ carriage design adapted to accept the older model barrel, and six 28cm K. L/40 ‘Kurfürst’ guns were built by placing old 28cm cannons onto a new carriage design. Both ‘Theodor Otto’ and ‘Kurfürst’ had ‘K.’ barrels, which had a slower rate of fire than the fast-loading ‘S.K.’ cannons of other railway guns, but the difference did not appreciably affect performance. Krupp also converted five 21cm cannons, used by the navy as fixed foundation guns since 1915, into railway pieces designated as the 21cm S.K. L/45 ‘Peter Adalbert’. Despite design differences, all these railway guns were functionally similar, having lifting jacks and a pivot mechanism for attaching the gun to its ground platform. The guns also had an equivalent range of about 18,500m.
Krupp also constructed eight 38cm S.K. L/45 ‘Max’ railway guns, which were much larger in calibre and size than its other railway artillery pieces. The genesis of these guns dated back to 1915, when the army successfully employed 38cm ‘Lange Max’ naval cannons on fixed foundations at Verdun, the Somme and in Flanders. At the end of 1917, when construction of several battleships was deferred in favour of U-boat production, a number of 38cm naval cannons became available for use as either ground or rail-mounted artillery. Krupp put eight of these barrels on E.u.B. mounts and delivered the first gun in January 1918. The 38cm ‘Max’ was the largest-calibre railway artillery gun fielded by the Germans and was employed by both the army and the navy. When fired from railway tracks it had a range of 24,000m, but from a ground platform the maximum range was 47,500m. Because of its weight – 273 tons – ‘Max’ needed a different ground platform than those used for the smaller 21cm, 24cm and 28cm railway guns. Instead of a pivot mechanism, the platform for ‘Max’ had a steel turntable. The first platforms had concrete foundations for the turntables. Later, by May, a more versatile all-steel platform that could be removed and installed at another firing site was provided for the guns.
In 1913, the German shipbuilding industry began construction of Bayern type battleships. In total, it was planned to build four such ships, distinguished by powerful protection and weapons. Two battleships were completed and transferred the fleet, while the third and fourth ships were only launched. Soon it was decided to stop construction, which, among other things, led to the release of a large number of various equipment and weapons. The main caliber of ships in the form of 38-cm guns, it was decided to use on land as weapons of special power.
According to some reports, for the first time, 38 cm SK L / 45 tools were used in the interests of the ground forces at the beginning of 1916. For this purpose, quite complex firing positions were equipped, equipped with massive concrete pedestals and corresponding means of guidance. Such a complex made it possible to attack targets in the entire allowable range of firing ranges, but was extremely difficult to operate. The construction of the stationary artillery complex took several weeks.
The characteristic flaws of the existing system have led to the emergence of a new proposal. An idea emerged to significantly improve the mobility of guns through the use of rail transportation systems. It was originally planned to use the railways only to deliver the gun to the position, but later it was found that a conveyor could be used as a mobile unit capable of firing from the wheels. According to various sources, work on the rail version of the artillery system began no earlier than 1916-17.
A promising railway cannon project was given a designation similar to that used with other developments in this field – 38 cm SK L / 45 (“38-cm fast reloading cannon with a barrel of 45 gauge”). The project was also given the additional name Max (“Max”) or Lange Max (“Long Max”). It should be noted that only an additional name allows to distinguish the railway version of the gun from the base ship. The development of the project was entrusted to the concern Krupp
Transportation of a large and heavy gun was quite a challenge, which required creating an entirely new conveyor with the appropriate characteristics. It was decided to use the already developed version of the transportation and deployment type Bettungsgerüst. In this case, a special complex with a dismantled artillery installation was to be moved along the railways. The undercarriage was required only for delivery to the place of combat work, after which the gun had to be deprived of it. This architecture provided all the required characteristics, but at the same time it allowed to accelerate the process of deploying weapons to the position in comparison with a full-fledged fixed installation.
Later it was decided to recycle the conveyor in accordance with the concept of Eisenbahn und Bettungsgerüst. Now the gun could not only shoot from a previously prepared stationary position, but also be used on any part of the track. In general, this installation option could solve all the tasks, however, it differed with some features. First of all, he had to have serious restrictions on the angles of guidance and firing range associated with the design features of the weapon and associated units.
Artillery installation “Max” was to be built on the already established scheme. Four trucks with four and five wheel pairs on each became its basis at once. Trolleys were locked in pairs and equipped with pivots for connection with the central element of the conveyor. The latter was a large and solid beam of complex shape and design, having all the necessary devices to be placed on the position and installation of the gun. The central beam of the conveyor was a unit of frame construction with a gap between the side elements. This space was proposed to be used for partial placement of the instrument in certain circumstances.
Due to the large mass and power, the gun was proposed to be equipped with a combined recoil damping system. The barrel was to be connected to hydropneumatic recoil devices, which, in turn, were placed on a movable cradle. The latter had the ability to move along the central beam of the conveyor and partially extinguished recoil. On the swinging cradle suspended between the side elements of the beam, placed a large and heavy counterweight. Used long-barreled gun had a tendency to lower the barrel. The installation of equilibrators was considered inexpedient, which is why a counterweight appeared over the trunk, next to the trunnions. It was made of two separate halves, pinned pivotally. In the transport position, they lay on the upper surface of the trunk; in the combat position, they converged and formed a rectangular structure.
As part of the new artillery installation was used naval gun 38 cm SK L / 45. It had a rifled barrel caliber 380 mm long 16,1 m. The total mass of the gun in the ship’s performance reached 80 t. Used wedge gate, moving in the horizontal plane. The gun was charged separately using a variable propellant charge. The latter consisted of a sleeve with the main charge and the required number of additional cards. The gun could accelerate the projectile to a speed of more than 1000 m / s and send it to a distance of 55 km. At the same time, the railway implement could have some limitations on the range characteristics.
380-mm gun could use shells of several types. The largest and heaviest was a fragmentation total weight of 750 kg. It contained 67 kg of explosive and could leave the barrel at a speed of 800 m / s. The firing range of such a projectile reached 32,4 km. Maximum speed and range were achieved using ballistic-cap munitions.
Due to the large mass of projectile and liner, the Max project involved the use of cranes and special vehicles. With their help, the ammunition was fed under the conveyor, behind the breech of the gun, and climbed the dismounting line. Depending on the firing position used, different devices could be used to work with projectiles.
Concern “Krupp” developed two options for the combat use of railway guns, differing from each other in equipping the firing position. The first, Bettungsgerüst, implied a long position preparation, which required up to three weeks. During this time, builders had to dig a pit with a diameter of 22 m and a depth of 3,5 m, and then build a special concrete structure in it. After this, a cylindrical pedestal for the instrument appeared on the position, surrounded by a stepped wall. On the pedestal there was a shoulder strap for mounting a gun mount.
Upon arrival, the calculation of the railway implement, using additional tracks and cranes, was to hang the conveyor platform over the constructed position, and then lower it onto the epaulet. Next, the carts were removed, the cranes were removed, and some other operations needed to start the combat work were performed. In particular, transport carts for projectiles were installed on the corresponding rail tracks.
The 38 cm SK L / 45 Lange Max gun in the Bettungsgerüst version could show the highest possible performance. Tumbovaya installation and epaulet allowed to direct the gun horizontally in any direction. The installation was raised above the bottom of the excavation, so that the elevation angles could vary from 0 ° to + 55 °. The maximum rise of the barrel allowed attacking targets at ranges over 45-50 km. Thus, the full potential of the gun could only be revealed at the cost of lengthy preparation of the firing position.
Work on the method of Eisenbahn und Bettungsgerüst was not so difficult and did not require lengthy preparation. For such shooting, one had only to arrive at the firing position, put the boots under the wheels and prepare the weapon for firing. For horizontal pickup when shooting from the railroad, a special mechanism was used, placed on the front carts. The presence of a movable support connecting them with the central beam, as well as a hinge connection with the rear carriages, allowed the transporter to move within the sector width 2 °. At the same time there were serious restrictions on the angles of vertical pickup: no more than + 18 ° 30 ‘. This restriction was introduced because of the length of the rollback, since at high elevation angles the breech could hit the way. The German military considered it inappropriate to disassemble the rails and cut a hole in the embankment: this method of increasing the pickup angles did not allow the complex to quickly leave the position. By reducing the maximum elevation angle, the firing range dropped to 22,2 km.
Complex Max turned out large and heavy. The total length of the system in the transport position reached 31,6 m. Mass – 268 t, without taking into account various additional means, such as ammunition, trucks for them, transport, cranes and, of course, building materials for the preparation of the position.
The assembly of the first transporters for a new type of railway complex began in 1917. Krupp companies delivered eight ship guns to fulfill the order. Initially, these guns were made to install on new ships, but the construction of carriers was canceled, which forced the commanders to look for a new use for them. The number of rail systems planned for construction was limited by the number of guns available.
In the winter of 1917-18, the army received the first samples of new weapons. In the same period, the construction of future fixed positions began. Flanders was chosen as the first theater of war for the new guns. The weapons were proposed for use in the course of the future Spring Offensive. Preparation of positions had to begin in advance, given the long construction time of concrete structures. Such structures were built until the end of the spring 1918, when a new version of the Bettungsgerüst installation appeared. Now some elements of the position had to be made not of concrete, but of metal, which made it possible to speed up construction work.
For the first time, 380-mm naval guns were used on land in February 1916, at the beginning of the Battle of Verdun. Complexes “Long Max” went to war only two years later. Interestingly, only one such system was transferred to the army, while the others formally remained naval. Nevertheless, despite such an organizational structure, the navy helped the ground forces in their battles. The operation of special-power weapons was conducted only on land as part of army operations.
Due to the high firing characteristics and the available power of the 38 cm SK L / 45 Max shells, they could show the required efficiency even without mass use. Usually no more than 2-3 guns acted on one front. Among other things, this made it possible to disperse railway artillery into several remote areas and use it in various operations. The presence of only a few railway guns on a stationary or mobile base made it possible to cause serious damage to the enemy at great depth without serious risk of destroying the guns by a retaliatory strike. However, only a few months remained until the end of the war, because of which special power tools simply could not participate in a large number of operations.
Probably for this reason, in November 1918, one of the guns was on the territory of Belgium, where it was captured by local troops. The remaining seven units were previously assigned to Germany, where they were planned to be transferred to the coastal defenses. At these places, eight guns met a truce, which accordingly affected their future. Seven guns, planned for the transfer of coastal artillery, could not be saved from disposal: they were dismantled in accordance with the conditions of the Versailles peace. The eighth gun went to Belgium and therefore did not go for recycling.
For several years, the Belgian troops studied and used the captured sample, after which it was decided to sell this instrument to France. In 1924, the only remaining “Max” changed owner. French specialists conducted full-scale tests, during which all the main characteristics of the gun were established. After testing the gun was sent to storage. As far as is known, it was not used by the army. In 1940, Nazi Germany attacked France, and she soon capitulated. Together with other available weapons and equipment, the German troops got the 38 cm SK L / 45 Max complex. Probably, the German troops were glad of such a trophy, but the operation of the captured gun was not planned. The subsequent fate of the sample is unknown.
In 2014, the Lange Max Museum was opened in Belgium, dedicated, as its name implies, to the Long Max tool. The museum exhibits a preserved instrument, dismantled from its installation. In addition, not far from the buildings of the museum is one of the surviving firing positions with a concrete base for the gun.
As part of the 38 cm SK L / 45 Lange Max project, the designers of the Krupp concern were tasked with creating a conveyor belt for transporting existing 380-mm ship guns. As in the case of other similar projects, this task was successfully solved, and the armed forces received the required equipment. Nevertheless, it happened late – in 1917-18, which is why new tools of special power could not have a noticeable impact on the course of the war as a whole, although they showed their capabilities in individual battles. But the late appearance did not allow Germany’s most powerful railway cannon to reach its full potential.
Ordnance experiments in the 1870s involving testing pressures in gun bores revealed that performance could be significantly enhanced by utilizing slower-burning gunpowder and longer barrels. Slow-burning large-grain powder, known as prismatic powder, prolonged the length of time that the charge acted on the projectile and thus increased both muzzle velocity and range. The problem with this was that the projectile left the barrel before all the powder was consumed. This could be solved by longer barrels, but that made muzzle-loading next to impossible. The slower-burning powders also required a powder chamber of diameter larger than that of the bore. All these factors, and the need to protect gun crews during the loading process, prompted a renewed search for an effective breech-loading gun.
Although breechloaders had been tried at sea in the modern era, beginning in 1858 in the French Gloire and later in the British Warrior, problems led to them being discarded. In 1864 the Royal Navy reverted definitively to muzzle-loading ordnance, but other nations, especially the French, moved ahead with breechloaders.
The old problem of ineffective sealing at the breech was only slowly overcome. In 1872 a French Army captain named de Bange came up with a “plastic gas check” that helped prevent escape of gases at the breech, and in 1875 France adopted the breechloader. At the same time brass cartridge cases, already used for small arms, came into use for the smaller breech-loading guns.
An accident aboard HMS Thunderer in the Sea of Marmora in January 1879 helped prompt the Royal Navy’s return to breechloaders. Simultaneous firing was under way, with the main guns fired in salvo; during this, one of the battleship’s 12-inch muzzle-loading guns misfired. This was not detected from the force of the discharge of the one gun, and both guns were run back in hydraulically to be reloaded. When they were again fired the double-charged gun blew up, killing 11 men and injuring 35 others. This could not have happened with a breech-loading gun, and in May the Admiralty set up a committee to investigate the merits of breech-loading versus muzzle-loading guns. In August 1879 after a committee of officers examined new breechloaders built by Armstrong in Britain and Krupp in Germany, the Royal Navy decided to utilize the breechloader in three battleships entering service in 1881-1882.
Another change in the period was to guns of steel, which accompanied enormous increases in gun size. Krupp in Germany began producing cast steel rifled guns in 1860. The change to steel guns was made possible by the production of higher-quality steel. At the same time that the Royal Navy went to the breechloader it adopted the all-steel gun, in which a steel jacket was shrunk over a steel tube and layers of steel hoops were then shrunk over this. The system of jackets and hoops over an inner steel tube was followed by one in which steel wire was spun on under tension varying with the distance from the bore. This helped eliminate barrel droop. Such “wire guns” continued in British service until the 1930s. Bore lengths of the guns increased from 35 to 45 calibers and even from 40 to 45 calibers.
The larger guns of the period required mechanized ammunition hoists and complex breech-loading gear. Their metal carriages recoiled on inclined metal slides that pivoted under the gun port. The slides were trained laterally by means of transverse truck wheels moving on racers, iron paths set into the ship’s deck.
Naval Gun Turret
Following the decision to arm ships with a few large-bore pivot-mounted guns as their principal armament, the next step was an armored turret to protect the guns and their crews, especially during the lengthy reloading process. During the Crimean War (1853-1856), Royal Navy captain Cowper Coles designed two floating batteries to engage Russian shore batteries at close range. The second of these mounted a 68-pounder protected by a hemispheric iron shield, which during action proved largely impervious to hostile fire.
In March 1859 Coles patented the idea of turrets aboard ship. He advocated guns mounted on the centerline of the vessel so as to have wide arcs of fire on either side of the ship and halving the number of guns previously required for broadsides fire. Coles’s persistence, coupled with the powerful support of Prince Albert, led the Admiralty in March 1861 to install an experimental armored turret on the floating battery Trusty. The test was a success, for 33 hits from 68-pounder and 100-pounder guns failed to disable it.
The Coles turret turned on a circumferential roller path set in the lower deck, operated by two men with a hand crank. Its upper 4.5 feet of armor came up through the main or upper deck and formed an armored glacis to protect the lower part. The crew and ammunition entered the turret from below through a hollow central cylinder.
The first British seagoing turreted ship was the Coles-inspired Prince Albert of 1864. It mounted four 9-inch muzzle-loading rifles, one each in four centerline circular turrets, turned by hand; 18 men could complete a revolution in one minute. The problem of centerline turrets in a ship of high superstructure and sail rig and very low freeboard (the latter the result of a design error) contributed to the disastrous loss at sea of the Coles-designed HMS Captain in 1870. Most of its crew drowned, Coles among them.
In the United States, John Ericsson’s single revolving turret the Monitor entered service in March 1862. The Monitor and many follow-on types all had very low freeboard. This lessened the amount of armor required to protect the ship, allowing it to be concentrated in the turret. Unlike the Captain, however, the Monitor had no high superstructure or sail rig.
Ericsson’s turret was all above the upper deck, on which it rested. Before the turret could be turned, it had to be lifted by rack and pinion from contact with the deck. A steam engine operating through gearing turned the turret around a central spindle. The Monitor was the first time that a revolving turret had actually been employed in battle, in its March 9, 1862, engagement with CSS Virginia.
Sharp disagreement continued between those who favored the revolving turret and supporters of broadside armament. Renewed interest in the ram-in consequence of the 1866 Battle of Lissa-and larger, more powerful guns helped decide this in favor of the turret. The ram meant that ships had to fire ahead as they prepared to attack an opposing vessel; heavier guns meant that ships needed fewer of them and that these should have the widest possible arc of fire. The elimination of sail rigs and improved ship designs heightened the stability of turreted warships.
Turrets continued to undergo design refinement and received new breech-loading guns as well as heavier armor, indeed the thickest aboard ship. Relatively thin top-of-turret armor on British battle cruisers, however, led to the loss of three of them to German armor-piercing shells in the Battle of Jutland (May 31-June 1, 1916). The battle cruiser turrets also lacked flash-protection doors and the means of preventing a shell burst inside the turret from reaching the magazines. The largest battleship ever built, the Japanese Yamato had 25.6 inches of steel armor protection on its turrets.
Hogg, Ivan, and John Batchelor. Naval Gun. Poole, Dorset, UK: Blandford, 1978.
Lambert, Andrew, ed. Steam, Steel & Shellfire: The Steam Warship, 1815-1905. Annapolis, MD: Naval Institute Press, 1992.
Padfield, Peter. Guns at Sea. New York: St. Martin’s, 1974.
Tucker, Spencer C. Handbook of 19th Century Naval Warfare. Stroud, UK: Sutton, 2000.
Hawkey, Arthur. Black Night off Finisterre: The Tragic Tale of an Early British Ironclad. Annapolis, MD: Naval Institute Press, 1999.
Hough, Richard. Fighting Ships. New York: Putnam, 1969.
Half-track carriers were one of the most versatile designs of all armoured fighting vehicles to be used during the Second World War. The Japanese Army had this type of vehicle, as did the French Army, but it was the German and American armies which developed their half-track vehicles to serve in a whole range of roles, from mounting anti-tank guns and field guns to serving as carriers for mortars. One of the first types to be developed for the mechanised infantry battalions of the US Army was the M4, which entered service in October 1941. It carried an M1 81mm mortar in a fixed mounting to allow it to fire rearwards from the back of an M2 half-track vehicle. Unfortunately this layout was not favoured, probably because the carrying vehicle had to be manoeuvred into firing position instead of simply being driven forward to open fire on targets, like standard self-propelled guns such as the M7 ‘Priest’ with its 105mm gun. A modification was made so that the crew could dismount the mortar in order to fire it on a baseplate from prepared weapon pits. The modified mounting corrected the drawback and fitted the mortar to allow it to fire forward from within the vehicle. It was operated by a crew of six men and carried ninety-six rounds for the M1 mortar, which comprised mainly HE but with some smoke and illuminating bombs. Between late 1941 and December 1942, the White Motor Company of Cleveland, Ohio, produced 572 of these vehicles, which went on to serve in mainly the European theatre. The design weighed 7.75 tons, had an overall length of 19.72ft and could reach speeds up to 45mph on roads. It measured 6.43ft in width and 7.4ft in height and carried a .30in calibre machine gun for self-defence with 2,000 rounds of ammunition. Some vehicles were armed with the heavier .50in calibre machine gun, and the crew also had personal weapons.
Another variant was designated as the M4A1, and from May 1943 the White Motor Company built 600 of these vehicles. This was slightly larger and heavier weighing 8 tons but still carrying ninety-six rounds of ammunition for the M1 81mm mortar, which was mounted to fire forward. A crew of six operated the vehicle and weapons, which included a .30in calibre machine gun with 2,000 rounds mounted for self-defence. The M4A1 was 20.3ft overall in length, 7.44ft in height and 6.43ft in width. It could reach speeds of up to 45mph on roads. Together with its M4 counterpart, these mortar carrying vehicles served with armoured units such as the 2nd Armoured Division, nicknamed ‘Hell on Wheels’, from 1942 and later served across Europe after June 1944. Despite the successful development of these two types of mortar carrier, the Ordnance Department decided to re-evaluate the layout and develop a third type of mortar-carrying half-track based on a modified M3 half-track and conduct experiments with an 81mm mortar mounted to fire forward over the driver’s cab.
Field trials and firing tests proved this new layout to be superior to the M4 design in some respects, and in June 1943 it was standardised as the M21. The White Motor Company, with its experience in developing such vehicles, was awarded the contract to build the new design, and between January and March 1944 produced 110 units. Meanwhile, trials were continuing using an M4 half-track to mount a 4.2in (107mm) mortar for use with the chemical mortar battalions. Mobility and firing trials were conducted to assess the feasibility of this combination to lay smoke screens. The mounting was the same as that used on the 81mm mortar but the recoil forces of this heavier weapon proved too great for the vehicle’s chassis, the trials were suspended and the project dropped. Two other projects, known as T27 and the T27E1, using the M1 mortar mounted in the chassis of tanks, were examined, but these were terminated in April 1944. The T29 to mount an 81mm mortar into a converted chassis of an M5A3 light tank was another short-lived project which never got off the drawing board. The Ordnance Department then tried mounting the 4.2in mortar on the M3A1 half-track, and this proved much better. For some reason the design team appears to have reverted to mounting the mortar to fire rearward out of the vehicle and the configuration was designated T21. A change of design to mount the mortar to fire forward resulted in the designation T21E1, and even mounting the weapon into a the chassis of an M24 light tank was considered, but it was not pursued and the complete project was dropped shortly before the end of the war in Europe in 1945. Two other proposals for self-propelled mortar carriers were the T36 and T96 projects. The T36 suggested mounting a 155mm mortar in the chassis of an M4 Sherman tank and the T96 a 155mm mortar onto the chassis of the M37 gun carriage. They were good ideas but by the time these proposals were put forward the war was coming to an end and the projects were dropped.
The M4, M4A1 and M21 mortar carriers were based on the M2, M2A1 and M3 half-tracks respectively, of which some 60,000 of all types were built. They served in various roles, including self-propelled gun and anti-aircraft gun platform with quadruple-mounted .50in calibre heavy machine guns known as the M16. There were also communications vehicles in this range. The White Motor Company built the prototype of the M21 in early 1943 as the T-19 and, following successful trials, it was standardised in July the same year. It was accepted into service in January 1944 and among the units to receive the vehicles was the 54th Armoured Infantry Regiment of the 10th Armoured Division, which later saw heavy fighting during the Battle of the Bulge in December 1944. The M21 had a crew of six to operate the vehicle, mortar and the machine gun for self-defence, while frames on the side of the vehicle allowed mines to be carried which could be laid for defensive purposes in an emergency. The vehicle had a combat weight of 20,000lbs (almost 9 tons) with an overall length of almost 19ft 6in. The height was 7ft 5in and it was almost 7ft 5in at its widest point. The barrel of the M1 81mm mortar was supported with a bipod and a special baseplate mounting which allowed it to be fired from the rear of the vehicle. A total of ninety-seven rounds of ammunition were carried and included smoke, illuminating and high explosive rounds. A store of forty rounds of ammunition was kept in lockers either inside the hull where the crew could access it easily ready to use. A further fifty-six rounds were kept in storage lockers, twenty-eight rounds either side of the hull, which could be loaded into the rear of the vehicle to maintain levels of ammunition ready to fire. This arrangement was the same on the M4 and M4A1 vehicles. The mortar of the M21 could be traversed 30 degrees left and right; for greater changes the vehicle had to be manoeuvred to face the direction of the target. The mortar could be fired at the rate of eighteen rounds per minute to engage targets at ranges of almost 3,300 yards with the high explosive rounds. The barrel could be elevated between 40 and 85 degrees to alter the range. The .50in calibre machine gun was fitted on a pedestal mount to the rear of the vehicle and a total of 400 rounds of ammunition were carried. From there the firer could traverse through 360 degrees to provide all-round fire support. The vehicle was only lightly armoured up to a maximum 13mm thickness.
The M21 was fitted with a White 160AX six-cylinder petrol engine which developed 147hp at 3,000rpm to give speeds of up to 45mph on roads. Fuel capacity was 60 gallons and this allowed an operational range of 200 miles on roads. The front wheels were operated by a standard steering wheel and the tracks were fitted with double sets of twin bogies as road wheels, larger ‘idler-type’ wheels at the front and rear of the track layout and only one return roller. The open top of the vehicle could be covered by a canvas tarpaulin during inclement weather and this could be thrown off quickly when going into action. Although only few in number, together with the more numerous M4 and M4A1 mortar carriers, the three designs provided excellent mobile fire support to infantry units wherever required. All three designs were equipped with radio sets to communicate and receive orders as to where to deploy if needed to fire against targets. Some units of the Free French Army were supplied with some fifty-two examples of the M21 self-propelled mortar vehicles, which were used during the European campaign.
One armoured unit, the 778th Tank Battalion, recorded of the mortar carriers attached to D Company in December 1944 that the fire support they provided was ‘instrumental on several occasions in assisting the advance of the infantry by placing fire on enemy gun positions and strongpoints that could not effectively be fire upon by other weapons’. The account continues by stating how ‘the two … mortar platoons, from advantageous positions on the west side of the Saar River placed harassing fire on the city of Bous, on the east side of the river. The platoon fired an average of 350 to 400 rounds per day into the city’. Continuing in their support of D Company, the mortar carriers fired from elevated positions at Bisten from where they suppressed German positions. Another armoured unit, the 746th Tank Battalion, was provided with fire support from mortar carriers and the unit recorded how these vehicles were able to ‘fire support to [cover] advance infantry elements in many instances when tank fire cannot be employed successfully’. This account continues by recording how self-propelled mortar carriers ‘were attached to an infantry regiment and further attached to one battalion and the assault company thereof. By following closely behind the advancing infantry, the mobile mortars lay down covering fires within their maximum range before displacing to the next bound. In some actions, the mortar carriers have backed down the axis of advance from one bound to another.’ Yet despite the mortar carrier’s effectiveness in supporting advances at very close quarters and keeping up with the advance, by the end of the war some officers in armoured units dismissed their usefulness. There were plans to develop the M21 vehicle to carry the larger 4.2in calibre mortar but it never entered service.
During its rearmament programme the German Army investigated the possibility of using half-tracked vehicles, and the way in which they could be developed into a variety of roles to support troops on the battlefield. By the time Poland was attacked, the German Army was equipped with several versatile designs of armoured half-tracked vehicles, mostly serving in the primary role of transporting troops on the battlefield and a secondary role as communications vehicles. Production of these designs continued so that several months later, when the blitzkrieg was launched against Western Europe in May 1940, the fleet of half-track vehicles was even larger. The two most widely-used types were the SdKfz 251 and the smaller SdKfz 250, which went on to prove itself to be no less versatile than its larger counterpart. In fact, by the end of the war in 1945; the SdKfz 250 had been developed into no fewer than twelve different configurations.
The German Army was quick to realise that light armoured half-track vehicles could be used on the battlefield as flexible workhorses. Of all the designs to enter service, it was the SdKfz 251 series, weighing 8.7 tons in its basic APC version and capable of carrying ten fully-equipped infantrymen as well as the driver and co-driver, which would prove invaluable in many campaigns, including North Africa. From the very beginning it complied with the requirements calling for an armoured vehicle capable of transporting infantrymen on the battlefield. Known as the Gepanzerter Mannschraftstran-portwagen (armoured personnel carrier) when it was first proposed in 1935, the vehicle quickly took shape and in 1938 the prototype was ready for field trials. It was produced by the companies of Hanomag and Bussing-Nag, which built the chassis and hulls respectively, and the vehicle was given the title of Mittlerer Schutzenpanzerwagen (medium infantry armoured vehicle) with the designation of SdKfz 251. The first vehicles were in service in 1939 and some were used during the campaign against Poland. Production was low at first, in fact only 348 were built in 1940, but there were enough numbers to be used during the campaign in the west in 1940. The SdKfz 251 was fitted with a Mayback HL42 TKRM six-cylinder water-cooled petrol engine which developed 100hp at 2,800rpm to give road speeds of up to 34mph, which was more than sufficient to keep up with the tanks in the armoured divisions.
The APC version was 19ft in length, 6ft 10in in width and 5ft 9in in height. The vehicle could cope with vertical obstacles up to 12in in height, cross ditches 6ft 6in in width and had an operational range of 200 miles on roads. Armour protection was between 6mm and 14mm, but the rear crew compartment where the infantry sat had no overhead protection, which exposed the troops to the elements and also the effects of shells exploding overhead. Two machine guns, either MG34 or MG42, were fitted to allow one to fire forwards from behind a small armoured shield and the weapon at the rear was fitted to a swivel mount to provide fire support for the infantry as they exited the vehicle. Being open-topped, the infantry could jump over the sides to leave the vehicle or exit through the double rear doors. The machine guns, for which 2,000 rounds of ammunition was carried, could be taken from the vehicle when the infantry deployed.