SMS Derfflinger II

A decision was also finally made about the roll-damping tanks, and despite the negative report by the commander of von der Tann saying they reduced the roll by just 33 per cent, it was decided to proceed with them, perhaps because preparations had already progressed too far to remove them and finance had already been approved. Interestingly, the following sister ship, Ersatz Kaiserin Augusta, did not have roll-damping tanks either planned or installed.

The final design of K – Derfflinger – was a striking ship and with it German shipbuilding reached a pinnacle as far as completed Panzerkreuzers were concerned. This class of three ships is often regarded as the best all-round capital ship of the period, and aesthetically is among the most handsome.

Prior to the outbreak of war it had been planned for Derfflinger to be completed on 13 September and the Kaiser had ordered the new Panzerkreuzer to be dispatched to the opening of the Panama Canal, which meant the cruiser would have to be in service on 1 October 1914. After that Derfflinger was scheduled to visit the 1915 Panama–Pacific International Exposition in San Francisco.

With the declaration of a state of war on 1 August 1914 it was determined to accelerate the completion and readiness of Derfflinger for the front, and in August pre-trials and acceptance of the ship’s hull, engines and auxiliary machinery and weapons were begun. The pre-trials were made jointly by the builders and the designated ship’s crew, a process that significantly reduced the trials period. Kapitän zur See Heinrich commented that: ‘The crew were initially drawn together from men that immediately before the outbreak of war were taken from the ships of the cruiser squadron from East Asia and had returned home and were retained in service. Most of the men had served on Scharnhorst and Gneisenau. They were practical men, well trained, and well developed physically. So, the men of the ship were very good.’ The commissioning commander, Kapitän zur See von Reuter, requested and was granted permission to commission the ship early and load munitions in Hamburg. Likewise, the torpedo nets would be brought from Wilhelmshaven to Hamburg and be installed at the constructor’s yard.

The ship met the contractual obligations, and the hull, engines and boilers were all in good condition when the ship was handed over – however, only one coat of paint had been applied internally. Since the ship had been fully outfitted the draught for the trials was 9.4–9.6m, instead of the intended trials draught of 8.33m.

Derfflinger manoeuvred well at high speed but at low speed not so well. Manoeuvring with the propellers alone was sufficient and met practical needs. Vibration of the hull at all speeds ahead and astern was slight and had no adverse effects on the armament. However, there was considerable vibration with the transition from going ahead to astern, especially in shallow water. This was to have an adverse effect, as will be shown.

The accommodation was generally good and the distribution of crew space gave no reason for complaint, although the commander’s cabin was too far aft and his day rest room on the bridge had no toilet. The stores and provision rooms and distribution rooms were of sufficient size and were sufficiently ventilated. Only the positioning of the meat store immediately above an oil cell was criticised and the store had to be moved. The absence of wooden furniture, on the basis that it posed a fire risk, was criticised and it was recommended that some wooden furniture be allowed. Ventilation was regarded as sufficient.

The view from the forward conning tower over the bow was obscured by turret B and the bow of the ship was not visible to the navigation Offizier or helmsman, so a steering guide had to be placed on the bow. Likewise the commander’s view from the bridge was restricted by the conning tower, mast and chart house, and not all of the horizon could be seen. It was recommended that a folding ‘flying bridge’ of light construction be situated on the roof of the chart house.

The designed performance of Derfflinger was 63,000shp and 25½kts, and this was exceeded with an actual performance of 76,634shp and maximum speed of 26½kts. Nevertheless, the trials were conducted with a draught of 9.4–9.6m instead of 8.33m and were run in shallow water, thereby reducing the performance. It was believed that if the trials had been run at designed draught and in deep water a speed 2kts higher would have been achieved. The contractual astern performance of 28,000shp was considerably exceeded with 37,000shp. Range was 5,400nm at 14kts.

The readiness of the ship and the completion of underway trials were twice interrupted by damage to both low-pressure turbines.

The first damage occurred to the port low-pressure turbine on the trip intended for determining compass deviation on 4 September. The repairs consisted of renewing the blades of the third, fourth and fifth stages of the low-pressure turbine and required the lifting and closing of the turbine housing, with the work taking five weeks.

The second damage was found in the starboard low-pressure turbine after going astern on 15 October. Approximately seventeen blades of the third stage were damaged and all the blades of the third stage were replaced. Although initially it was thought the damage was of a minor nature, the blades were reinforced with strong wire to make them shock-resistant. At the same time, the blades of both low-pressure turbines from the third stage on received lock wire in the joints of the blade segments for added strength, while to keep the blades in place the clearance of the entire blades of the ahead and astern low-pressure turbines was increased, by at least 3mm, by filing the blade ends when the turbines were warm and expanded. The edge of the upper turbine blade ends was rounded and the free axial play between the guide vanes and blades was brought to 11mm. The completion of this work required three weeks.

It was later believed by engineers and naval architects that the cause of the damage was vibration brought about by going from ahead to astern. This vibration probably caused resonance vibration of the turbine blades, some of which were up to 40cm in length and caused them to contact the guide vanes in between – resulting in the so-called ‘turbine salad’.

Although the work of the dockyard workers and the crew was commended, it was pointed out that working in a confined space and with no previous experience caused some delays.

The boiler plant fully met its requirements, as did the auxiliary machinery. Only half the turbo-fans were required to provide enough air for the forced draught for the boilers.

The electrical system was good and the turbo-dynamos worked perfectly. However, the diesel dynamos suffered teething problems.

Operational History

At noon on 1 September 1914 Derfflinger was commissioned into the Imperial Navy at the Blohm & Voss Dockyard in Hamburg. The priority was to complete the ship and carry out trials, and for this the ship would have to go to Kiel and the Baltic. At 04.40 on 2 September 1914 Derfflinger reached Brunsbüttelkoog and then entered the Kaiser Wilhelm Canal for the trip to the east. At 15.25 she reached Holtenau at Kiel and the commander recorded: ‘South lock. The ship steers well and could partly run at a speed of 12kts.’ At 16.00 the ship made fast to buoy A8 in Kiel harbour and began taking aboard oil, 1,200 tonnes of coal and other materiel. At this stage of the war, ships had to pass through the canal at reduced draught.

On 4 September Derfflinger suffered the first damage to the port low-pressure turbine; however, trials continued with combat training, transferring torpedoes, boat handling and munition handling for the heavy artillery. On 11 September she transferred to the imperial dockyard for repair work using starboard engine and with the assistance of two tugs. Whilst the repair work on the port low-pressure turbine continued, the starboard turbine was also opened and inspected. On 24 September it was reported that Allied warships would break through the Great Belt into the Baltic, and therefore the following day Derfflinger conducted exercises in Kiel Bay, with the ship ready for action. The attack did not materialise and on 26 September turbine repair work continued.

On 9 October shooting practice was carried out and on 13 October there was a calibre shoot on the target ship Bayern. The same day the port low-pressure turbine was reported ready for further employment. The following day Großadmiral Prinz Heinrich, brother of the Kaiser, visited the ship. Then, on 15 October, damage occurred to the starboard low-pressure turbine, again beginning with the third stage rotor blades. Repair work was undertaken on the starboard low-pressure turbine and at the same time modifications were begun on the port low-pressure turbine. This work concluded on 9 November after which the trials were continued, finishing on 13 November. At 01.00 on 14 November Derfflinger began the canal trip back to the North Sea and after replenishing provisions the ship arrived in Schillig Roads on 16 November.

The BdA, Kontreadmiral Hipper, visited the ship on 18 November and the following day Derfflinger joined the I AG as tactical number 3. On 20 November exercises were undertaken in the North Sea, including firing four torpedos, and on return Derfflinger passed the Jade bar with a draught of 9.2m.1 Training with Blücher followed on 24–25 November and then the arduous North Sea routine of picket duty and being on short notice for raising steam began. On 9 December the I AG made an abortive advance into the Helgoland Bight.

At 04.00 on 15 December 1914 Derfflinger weighed anchor and put to sea in the unit of I AG on an operation to bombard the English coast. During the night passage, Kapitän zur See von Reuter lamented the poor visibility ahead from the conning tower after the stern lantern of the next ship ahead had been extinguished. At 08.56 on the morning of 16 December the high coastline came in sight and very soon Robin Hood’s Bay was correctly identified. At 09.02 Derfflinger opened fire on the Scarborough battery and barracks and at 09.08 transferred to the coast watch station and the Grand Hotel. Fire was ceased at 09.12 as Derfflinger turned onto a northerly course and then reopened fire between 09.16 and 09.23 on the same targets. A total of 176 15cm and 145 8.8cm shells were fired at these targets. Course was then maintained along the coast to Whitby at high speed. From 10.08 to 10.13 the signal station and guard house at Whitby were taken under fire.2 Only fifty-three 15cm and twelve 8.8cm shells were fired on Whitby. At 10.14 von der Tann set the signal ‘Z 0’ – ‘follow the leader’ – and course was taken to the cruiser assembly point out at sea. At 10.20 the I Group came in sight to the NW and at 10.52 Derfflinger was on a course ESE, at a speed of 23kts.

From reconnaissance by the German small cruisers it was known that British heavy forces were nearby and at 12.50 the signal was given ‘Clear ship for battle!’ The I AG was almost trapped by the British 1 Battle Cruiser Squadron and the 2 Battle Squadron, but the only enemy forces sighted from Derfflinger were destroyers of the ‘A’ class sighted at 15.07, to port on an opposite course and at a range of 200hm.

Conditions on 16 December 1914 were quite stormy, with a NW wind force 7–8, and the swell from the NW Strength 6. For the first time Derfflinger was being driven under difficult weather conditions. Bad weather preparations were taken in time and the ship remained dry inside. Kapitän zur See von Reuter continued:

The ship was exceptionally seaworthy. Both the upper roll-damping tanks were filled, and the movements were apparently lower compared with other Panzerkreuzers. Whether the roll-damping tanks are to be retained is to be determined by trials, which on 16 December were not possible because of combat conditions. The sloshing around of water and the noise of air rushing backwards and forwards through the air channel had an unfavourable influence on service in the FT (wireless) room. Consideration should be given for the arrangement of the FT room on new cruisers for this.

Whilst steaming against the swell at high speed (23kts) the ship has taken the usual water onboard, but, with no breakers over the bow. Nevertheless, the holes of the sounding position and vision slits are tight.

During the night the I AG steered in loose formation and continued to Amrum Bank and then east of Helgoland to the Jade, where the unit arrived around 19.00 on 17 December 1914.

The next large-scale operation Derfflinger was involving in was the Dogger Bank Battle. At 18.00 on 23 January 1915 Derfflinger weighed anchor and steered to seawards as tactical number 3. The wind was a north-easterly at force 3 and the night was very clear. At 05.34 on the morning of 24 January ‘Alarm!’ was given after a searchlight was briefly observed to the NW. At 08.00 the enemy recognition signal was recognised as ‘UA–F’ and at the same time shooting was observed from the light forces ahead. The German Panzerkreuzer turned to the west, towards the enemy and advanced in this direction. At 08.30 Derfflinger was cleared for battle and the I AG turned away from the enemy, taking course SE. In the poor light the individual enemy ships could not be clearly distinguished. Therefore the turn away was made until there was a clearer understanding of the situation. At 09.17 the signal was given for 23kts. As the British destroyers came within range at 09.42 Blücher received orders to open fire on them. Derfflinger, keen to be in the action, moved out of the line and requested permission to open fire likewise, but the reply was the signal ‘Z 0’ (‘follow the leader’), so she again sheered back into line. When the ship received fire from starboard aft at 09.55 it came as a surprise to those aboard, as several groups of ships had approached unobserved in the smoke and haze. At 10.11 Derfflinger opened fire with the heavy artillery on the first ship from the left, at first with eight guns, then from 10.23 with four-gun salvos. From 10.23 to 10.35 the forward turrets and medium-calibre guns fired on some light cruisers. When at 10.35 the first target was out of range, target was changed to the second ship from the left, then for a brief minute target was changed to the third ship from the left. At 10.36 target was again taken on the original target, the first ship from the left, range 172–190hm. Several hits were observed on the first two ships and fire was continued until the British ships turned away. From 11.48 until noon the medium artillery and even the light artillery fired on two British destroyers, which turned away. During the battle Derfflinger fired a total of 234 30.5cm armour-piercing shells and seventy-six 30.5cm explosive shells. A total of forty-eight 15cm shots were fired and just five 8.8cm explosive shells.

During the battle Derfflinger was hit only once: a heavy shell struck the armoured belt at 11.40. A second shell landed short and caused heavy vibration at the time. There were several other near misses, which fell to port and starboard aft and caused some flooding. Derfflinger suffered no losses.

At 19.40 Derfflinger anchored in Wilhelmshaven Roads and the following morning ran into the imperial dockyard and made fast to Berth BV for repairs, including a period in the floating dock from 27 January – 16 February.

Kapitän zur See von Reuter made some interesting observations about the battle, saying that, despite clean boilers and the excellent performance of the stokers and personnel, the engines could only make 260 revolutions, driving her at 24kts. The draught was 9.4m, and the speed deficiency was attributable to the shortening of the low-pressure turbine blades, he said. However, this observation is at odds with his former comments after 16 December, when he commented that Derfflinger was the fastest of the German Panzerkreuzers.

Further, he commented that the British sought to hold the range beyond that of the Germans, but inside their own, that is about 195hm, and surmised that this was the upper limit of their range. He said the British superiority in speed allowed them to make greater course alterations to throw off the German aim, up to four points, or 44°. He believed two ships were firing on Derfflinger but their fire was slow, but nevertheless they held their aim. He concluded that lagging behind in heavy artillery calibre had been a mistake.

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