THE MOLTKE CLASS

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Moltke. She was fitted with ten 28cm guns, trainable within a wide arc on both sides. The antitorpedo nets, initially fitted on most capital ships, were removed during the war due to their limited effectiveness and burdensome handling.

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Goeben at La Spezia in early 1914. Since Italy was part of the Triple Alliance, until she declared her neutrality in early August 1914, Goeben was entitled to have access to Italian naval bases. Her main support harbour in the Mediterranean was, however, the Austrian base of Pula on the Adriatic.

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Moltke, 1914

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Goeben, 1912

In defining the designs of Grosse Kreuzer ‘G’ and ‘H’, included in the 1908 and 1909 building programmes, the RMA avoided the mistake made by Britain, which failed to introduce in the Indefatigable class significant improvements over the Invincibles. In comparison to Von der Tann, the new German battlecruisers were, in fact, much larger, equipped with a more powerful main battery and better protected. This was possible thanks to the increased budget allocated to battlecruisers, which rose from RM36.7 million in 1907 to RM44.1 million in each of the two following years.

Design, Construction and Cost

The design process of Grosse Kreuzer ‘G’ started in April 1907. Faced with the alternatives of switching to a larger calibre (30.5cm) main gun, as in the new Helgoland class battleships, or increasing the number of existing 28cm guns, Tirpitz and Department K choose the latter. Given that Britain was building a larger number of battlecruisers than Germany, it was indeed advisable to have a greater number of guns, rather than increase their calibre. Moreover, the RMA considered the 28cm was sufficient even to engage battleships.

Initially, the 28cm SK L/45 was selected and a preliminary design – dubbed ‘G2i’ – for a 22,000t battlecruiser equipped with five twin turrets and capable of developing 24 to 24.5 knots, was approved by the Kaiser on 28 May 1907. The project definition continued at a slow pace, due to both the many changes gradually introduced and the work overload affecting Department K. At one point, building Grosse Kreuzer ‘G’ as a repeat of Von der Tann to save time was even considered, postponing the introduction of improvements to the next ship, Grosse Kreuzer ‘H’. This proposal, however, was set aside, and on 15 May 1908 Tirpitz decided that Grosse Kreuzer ‘G’ and ‘H’ had to be identical. On 17 September, the RMA entrusted the construction of ‘G’ to the Blohm & Voss shipyard, which had submitted the lowest bid in anticipation of winning the contracts for both ships. The order for the first battlecruiser was signed on 28 September and, on 8 April 1909, Blohm & Voss also secured the contract for Grosse Kreuzer ‘H’.

Moltke11 was laid down on 7 December 1908, launched on 7 April 1910 and declared ready for the acceptance tests on 30 September 1911. She entered service on 31 March 1912. Goeben12 was laid down on 12 August 1909, launched on 28 March 1911, declared ready for acceptance tests on 2 July 1912 and commissioned on 2 August. Moltke cost RM44.08 million, spread over four budget years (1908-11), and distributed as follows: hull and propulsion, RM29.15 million; guns, RM14 million; and torpedo armament, RM0.93 million. The cost of Goeben was almost identical: RM44.125 million over 1909-12.

General Features

The main design features of the Moltke class (overall length 186.6m, beam 29.4m, design displacement 22,979t) were largely superior to those of Von der Tann. In particular, the greater size of the hull caused an overall increase of about 3,600t in the design displacement. The table on pages 156-7 shows displacement, dimensions and the ships’ main characteristics. This overall increase was due to several features. 1,000t came from a hull that was finer at the ends and wider amidships. An additional 1,000t were due to a greater freeboard and the installation of an additional 28cm turret and the consequent lengthening of the ship’s citadel caused an increase of 900t. The installation of more powerful machinery resulted in an additional 450t and, finally, larger ammunition stowage accounted for 100t.

The hull was divided longitudinally into fifteen watertight compartments and horizontally into six decks. Extensive compartmentalisation and a double bottom extending for 78% of the hull length provided underwater protection. In addition, there were side longitudinal bulkheads that provided further compart-mentalisation in the central and aft sections of the hull. There were two passageways located along the hull sides in the upper, lower platform and hold decks, running from approximately the foremost boiler rooms to ‘C’ turret magazine. Another two middle passageways, only in the upper platform deck, ran along the boiler rooms.

The forecastle rose up gently up to 7.6m far forward, while aft it continued up to the superfiring turret. The freeboard was increased by about 1m at the battery deck but reduced at the stern. The stem was nearly straight, instead of the pronounced ram bow fitted on Von der Tann.

The forward superstructure included the main control tower, two 8.8cm guns, the chart room and the bridge and the flag bridge. The rear part of this superstructure supported the forward funnel, which was higher than the aft funnel because it had a hood. The foremast was just forward of the fore funnel. Two searchlight platforms were fitted on each side of the fore funnel; the air vents for the boilers were located at its base, which also supported two derricks for handling the service boats. The aft superstructure included the secondary conning tower and a lattice frame with two platforms, each supporting two searchlights.13 These were installed aft, rather than on the sides of the aft funnel, to move them away from the flash and blast of the 28cm wing turrets. The aft funnel was not fitted with an outer coating; it was no longer needed since the aft searchlights were moved onto separate platforms. At the base of the aft funnel, there were the air intakes for the ventilation of the lower decks.

The barrels of the 28cm guns were 1.4m longer than Von der Tann’s, due to the transition from 45 to 50 calibres. This resulted in a corresponding increase of the traversing radius, thus requiring an adjustment of the funnels’ positioning, with a consequent increase in length of the ship’s citadel. The original design foresaw lattice masts; concerns related to the increased volume of these structures, their stability in case of hits, and potential interference in the operation of the W/T equipment led to the adoption of metal pole masts. After 1914, a fire-control position was added on the foremast. The Moltkes were equipped with bilge keels to improve stability. Six turbo generators supplied 1,500kW at 225V, powering the lighting and communication systems and the training servo-mechanisms of the large calibre turrets. The turbo-generators were housed in four dynamo rooms, two positioned along the centreline and the other port and starboard of the forward engine room, in the upper platform deck. W/T fitting was the same as on Von der Tann. Anti-torpedo nets were originally fitted but they were removed in 1916.

The Moltkes’ metacentric height was 3.01m. The angle of maximum stability was 34° and the angle at which stability vanished was 68°. Complement included forty-three officers and 1,010 men; when serving as flagship, there were an additional thirteen officers and sixty-two men.

Protection

The increase in displacement allowed for a considerable strengthening of the Moltkes’ protection, compared to Von der Tann. However, the weakness represented by the thinner armour of the barbettes behind the main armour belt was not eliminated. The main belt, consisting of KC steel plates, extended over 112m between the barbettes of the forward and the aftermost large calibre turrets. Maximum thickness was 270mm on a height of 175cm, 35cm of which was below the waterline. The belt tapered upwards to 200mm at the battery deck level (or at the upper deck outside the citadel) and to 130mm at the lower edge, 175cm below the waterline. The main belt was closed by 200mm bulkheads fore and aft. Beyond the main belt, side armour extended towards the bow and stern with a reduced thickness of 100mm.

The citadel enclosing the 15cm guns was protected by 150mm side armour between the upper and battery decks and was closed by bulkheads of equal thickness. The side protection of the main conning tower was 350mm, with an 80mm roof. The aft conning tower featured 200mm in side protection and a 50mm roof. The main gun turrets’ armour was unchanged from Von der Tann (230mm front, 180mm sides and 90mm flat roofs). The thickness of the barbettes was 200-230mm above the main belt but it was reduced to 80mm behind the battery side armour and to 30mm behind the main belt. Horizontal protection was 75mm inside the citadel, equally divided among the upper, battery and armoured decks. The thickness of the sloping sides of the armoured deck was 50mm. Outside of the citadel, protection was provided by the armoured deck, with a thickness between 50 and 75mm. A longitudinal torpedo bulkhead ran 3.75m inside the main belt with a thickness of 30mm, increasing to 50mm on the sides of the ammunition magazines.

Machinery

Moltke and Goeben were equipped with twenty-four coal-fired Schulz-Thornycroft boilers. They were housed in groups of three in eight separated rooms amidships. The watertight compartment that housed ‘B’ turret magazine and some auxiliary equipment separated the two forward boiler rooms from the aft boiler rooms. In turn, these were split into six compartments, obtained by dividing two adjacent boiler rooms with two longitudinal bulkheads.

Steam was raised at 16atm and fed two groups of Parsons turbines, powering as many shafts fitted with three-blade propellers, 3.74m in diameter. The Moltkes, like Von der Tann, featured two side longitudinal bulkheads, which split the engine rooms into port and starboard compartments. The two forward engine rooms housed the HP turbines, which operated the outer shafts. The aft engine rooms housed the MP turbines, which ran the inner shafts.

Design power was 52,000shp, providing 25.5 knots at 260rpm. This value was greatly exceeded during speed trials, in which Moltke attained 85,782shp at 332rpm, and a top speed of 28.07 knots. Goeben achieved 85,661shp at 330rpm, and 28 knots. Design coal stowage was 1,000t; the maximum 3,100t and endurance was 4,120 miles at 14 knots. After 1916, the boilers were equipped with tar oil sprayers, thus obviating the poor quality of available coal; oil capacity was 200t.

Moltke and Goeben had two rudders in tandem. Since the rudders were 12m apart, this layout increased manoeuvrability at slow speed and the ship’s survivability. However, this also remarkably increased the ship’s turning diameter at slow speed. When turning at full rudder, speed loss could reach 60%, while heeling could reach 9°.

Armament

The main armament consisted of ten 28cm L/50 guns in five Drh. LC/08 twin mountings: a bow turret (‘A’), two aft (‘C’ superfiring over ‘D’) and two wing turrets (‘B’ to starboard and ‘E’ to port).14 As in Von der Tann, this layout allowed firing a full broadside of ten guns within a wide arc (about 75°) on both sides. The height of the gun axis was 8.79m above the waterline for the forward turret, 8.43m for the wing turrets and 8.61m and 6.25m for the aft turrets. Each mounting weighed about 445t, and had a crew of seventy.

Elevation of the large-calibre guns was -8°/+13.5°, 6.5° less than Von der Tann. Therefore, the maximum range was limited to 18,100m.15 When the maximum elevation was increased to 16° in 1916, range was extended to 19,100m. As Yavuz (ex-Goeben), the maximum elevation was further increased to 22.5°, in order to enable her to deal with the newest Russian battleships, armed with 30.5cm guns, operating in the Black Sea. The guns of Yavuz could then achieve a maximum range of 21,700m. Thanks to the increased length of the barrel when compared with the 28cm L/45, the new gun fired the 302kg AP shell with a muzzle velocity of 880 mps and corresponding muzzle energy of 116.9MJ. Maximum rate of fire was three rounds per minute while the weight of the full broadside (ten rounds) was 3,020kg. Ammunition outfit totalled 810 rounds. The capacity of the magazines was 150 rounds for the wing and aftermost turrets and 180 rounds for the other two turrets.

The secondary battery consisted of twelve 15cm L/45 guns on MPL C/06 mountings, casemated on both sides of the ship’s citadel. Each gun’s axis was 5m above the waterline. Ammunition outfit was 150 rounds per gun (1,800 in total). Two 15cm guns were removed from Yavuz in May 1915 and used to strengthen the fortress of In Tepe, on the Dardanelles.

To defend against torpedo boats and destroyers, the Moltkes were initially armed with twelve 8.8cm L/45 naval guns: four were placed near the bow, two in the fore and four in the aft superstructure, and two on the upper deck, aft of the 15cm battery. These 8.8cm guns were first reduced to eight, removing the bow guns because they were flooded when the ship steamed at full speed; another four guns were removed in 1916. The remaining 8.8cm guns were replaced by four AA guns on MPL C/13 single mounts, which were installed on the aft superstructure. Ammunition outfit for these guns totalled 3,200 rounds (200 per gun). Moltke and Goeben were also equipped with four 50cm underwater torpedo tubes (one forward, one aft and two on the broadside), with eleven torpedoes carried.

Moltke

In April-May 1912, Moltke paid a visit to the United States along with the light cruisers Stettin and Bremen. In July, she escorted the Kaiser’s yacht during a visit to St. Petersburg. Back in Germany, Moltke became the flagship of 1. Aufklärungsgruppe and served as such until Rear-Admiral Hipper transferred his flag to the new Seydlitz, on 23 June 1914. Moltke was interned at Scapa Flow on 24 November 1918 and scuttled by her crew on 21 June 1919. Raised in June 1927, she was scrapped in Rosyth in 1927-9.

Goeben

In October 1912, after the outbreak of the First Balkan War, Germany decided to send a naval Division to the Mediterranean to exert influence in the area. On 4 November, Goeben, escorted by the light cruiser Breslau, sailed from Kiel to Constantinople, where they arrived on 15 November. At the end of the war in May 1913, the ships were supposed to return to German waters but the reopening of hostilities, in the Second Balkan War, dispelled this notion. On 28 June 1914, the day Archduke Franz Ferdinand was assassinated in Sarajevo, Goeben was cruising in the eastern Mediterranean, from where she immediately sailed for repairs at the Austro-Hungarian naval base of Pola (today, Pula in Croatia). Goeben was formally transferred to Turkey on 16 August 1914 and renamed Yavuz Sultan Selim. However, the German crew continued to man the battlecruiser until November 1918. Yavuz remained in service under the Turkish flag until 20 December 1950, when she was placed in reserve. Deleted from the navy register in 1954, she was offered to Germany in 1963, with the proposal to turn her into a floating museum. Following the rejection of this idea by the German government, in 1971 Yavuz was sold for dismantling and scrapped in 1973-6.

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