Chapter 15: Anatomy Of A Battlecruiser
Turret “Albert” of SMS Helgoland. Even though the Helgoland Class mounted 12-inch rifles, this picture gives you a good idea of the size of a main battery turret compared to the seaman standing at left. The turret is massive and squat, with heavy and menacing guns. Just beneath the gun barrels, you can see the skylights opening above the crew quarters in the forecastle. The armored covers are raised to the vertical position, while the hinged glass lids are opened to allow air to circulate.
IMPERIAL DOCKYARDS: CUXHAVEN
By: Dreadnought & AP
Chapter 15:
ANATOMY OF A
BATTLECRUISER
Shipyard builder’s slip– circa 1910. The construction process has just begun, and you can see the forefoot of the ship’s keel in the upper left corner.
THE CONSTRUCTION
On 26 September 1907, the construction contract for “Grosse Kreuzer-F” was awarded to Blohm & Voss Dockyard, Hamburg. The shipyard had previously built the pre-dreadnought battleship Kaiser Karl der Grosse in 1898, and after that, the armored cruisers Friedrich Carl, Yorck, and Scharnhorst. Blohm & Voss was much favored by the Kaiserliche Marine, and with good cause – they turned out finely finished and properly built ships – and quicker than other German yards.
The new cruiser was expected to cost 36.5 million Marks – twice the cost of Scharnhorst, and a 33% increase over Blucher. And Tirpitz had gone to the Reichstag and traded on all that “public goodwill” to explain why the cost of “Grosse Kreuzer-F” had jumped so sharply. The Reichstag could see the necessity of countering the new British dreadnought battleships and cruisers – and they approved the funds -- but with little enthusiasm. This uneasy political/fiscal situation would be a major problem for the remainder of the Kaiserliche Marine’s existence. The Naval Laws had been based on the premise of fairly stable building costs – but that would quickly be seen as a really bad assumption. As everyone knows, when customers create a demand – prices go up. And, as we have already seen, each succeeding warship class grows -- the guns get bigger – the armor thickness increases – speed must be higher. And that always means more money.
The ship’s keel was laid on 21 March 1908, and the hull launched not quite a year later. At the christening ceremony, she was named in honor of Ludwig Freiherr von und zu der Tann, a General of Infantry in the Royal Bavarian Army, and a veteran of the First Schleswig War (1848), the Austro-Prussian War (1866), and the Franco-Prussian War (1871). He was conspicuous for his bravery, and much decorated by the Kings of Bavaria.
SMS Von der Tann – profile view and deck plan. Unlike other warships, Von der Tann’s overall appearance changed very little during her career. She would remain a beautiful vessel – long and sleek, with clean lines and uncluttered decks.
SMS Von der Tann was the first Imperial German battlecruiser. The Naval High Command could call her a “Grosse Kreuzer”, and the fighting sailors could call her a “Panzerkreuzer”, but she was undeniably a battlecruiser. She had not been designed for policing functions on distant colonial stations, but to stand in the line of battle. More specifically, she was designed to overpower the British Invincible Class battlecruisers. A casual glance will show the layout of her guns was very similar to HMS Invincible – but the similarity is all visual – and stops there. In truth, Von der Tann was, in every respect, a great improvement over the original British concept.
SMS Von der Tann easing through the west entrance to Cuxhaven Roadsted. Two Nordwind and two Passat Class tugs standby to assist. At top right, you see the second generation battlecruiser SMS Moltke lying at her berth along the breakwater. At lower left, pulling “guard duty”, is the gunboat USS Erie (See previous chapters.). Von der Tann and Erie are courtesy of @Barroco Hispano. Moltke and tugs are by @AP. Sea floor coral heads by NBVC.
GENERAL CHARACTERISTICS
The new cruiser displaced 19,370 tons -- a considerable increase over Blucher -- and fully 2,000 tons heavier than Invincible. At 563 feet, she was longer than previous classes, with a hull constructed of transverse and longitudinal frames, and riveted hull plating made of Siemens-Martin “mild steel”. The “mild steel” would be more flexible when hit with shells or splinters and would warp or buckle rather than shattering. There were fifteen watertight compartments and six deck levels, with a double bottom running 75% of her length – a significant increase of internal compartmentalization. (Internal subdivision slows flooding and confines it to a smaller area.) To counteract the rolling problem habitual to all German cruisers, “Frahm Anti-Roll Tanks” (developed at Blohm & Voss by Dr. Frahm) were installed for the first time in a large warship. Unfortunately, the decision was made during construction, and they were too small and fitted too far inboard. Proving ineffective on trials, they were converted to coal bunkers. Bilge keels were later fitted to improve stability.
All interior decks were steel plated and covered with linoleum, while the exterior (“weather”) decks were steel plated and covered with 2.5 inches of teak planking. Forward, she had a narrow, raised, forecastle deck to accommodate the main battery turret, bridge superstructure, and the first funnel. The purpose of the raised deck was to keep heavy seas from washing over the bow. Unlike the ungainly, high-sided, British battlecruisers, the Kaiserliche Marine cruisers had too little freeboard – even with a raised forecastle. During heavy weather, Von der Tann was very wet, and personnel were not allowed to move about the weather decks. Aft of the forward superstructure, besides three main battery turrets, there was one small funnel and ventilator structure amidships, and a small aft control structure beyond that. The careful arrangement of her machinery spaces below decks allowed the “minimalist” superstructure to be placed well clear of the main battery turrets and firing arcs. The deck plating in the midships area was specially reinforced to withstand the blast pressure of cross-deck firing. The weather deck was low and flush all the way to the fantail.
This view of Von der Tann will give you a sense of her sleek lines. Her length to width ratio was 6.5 to 1 – giving her enough beam for a stable gun platform while narrow enough to achieve good speed. She is built for speed – with her powerful gun battery on prominent display.
In an unusual move, the crew quarters were placed aft of the stern turret barbette on the “battery deck” and “armored deck” below that – with only a few berthed in their traditional forecastle space. The officers, out of necessity to reach the bridge in a hurry, were billeted forward, beneath the forecastle deck. The experience proved unsatisfactory and was not repeated. (Imagine an off-duty Watch Officer trying to sleep while the cruiser pounds into a “head sea” at 18 knots.) Her crew consisted of 41 officers and 882 enlisted men.
Von der Tann’s electrical needs were filled by six turbo-generators totaling 1,200kw output at 225 volts. This supplied lighting, communications, wireless, main gun turret traverse, and searchlights -- linked through the ship’s mains. As a precaution, the generators were divided between two dynamo rooms to provide redundancy in case of battle damage. (See Chapter 13 for dynamo problems suffered by HMS Lion.) Two searchlight platforms with four lights, along with an observation platform, were stepped against the foremast – with a similar installation on the mainmast.
As a standard feature of German capital ships of this period, Von der Tann was equipped with a drainage and pumping system which could drain any compartment in the ship. Two large drain pipes ran down each side of the ship and connected to a pump room with three high-capacity centrifugal pumps (two steam driven – one electrical). In an emergency, the condenser pumps could also be connected to the drainage system. The ship also carried several portable, electric “leak” pumps.
In accordance with a 1909 Reichsmarineamt directive, the cruiser was equipped with two wireless transmitters, three receivers, and as many antennas. In a 1912 refit, an additional transmitter/receiver was installed in the forward conning tower.
ANTI-TORPEDO DEFENSE NETS
The Russian pre-dreadnought battleship Evstafiya – circa 1910 – with her torpedo nets deployed.
Von der Tann’s original design included an anti-torpedo net system. Torpedo nets came into common use during the 1890’s to protect anchored warships from the growing threat of torpedoes. Multiple horizontal booms were fixed (usually on swivel joints) to the side of the ship at regular intervals, a few feet above the waterline. At the end of this 40 foot boom, a heavy gauge, steel mesh net was suspended. The net hung down into the water far enough to prevent an incoming torpedo from hitting the hull of the ship. At 40 feet in length, the boom provided enough distance for a torpedo to explode against the net without damaging the ship. When preparing to get underway, the nets were hauled up, furled, and the booms collapsed against the ship’s hull. The whole thing was then secured for sea. Clearly – it was a cumbersome and somewhat primitive system. Not to mention the added weight of the nets and booms.
Various tricks and strategies were devised to tactically defeat the nets, but by 1914, torpedo warheads had become powerful enough to damage the ship regardless of the net. During the Battle of Jutland, exposed torpedo nets suffered severe battle damage, and nets dragging alongside threatened to snag the ship’s propellers unless cut away and allowed to sink. Consequently, the Kaiserliche Marine removed them as quickly as possible.
The crew of SMS Weissenburg recovering torpedo nets in preparation for getting underway.
PROPULSION PLANT
Von der Tann was the first German capital ship to have steam turbines installed. There were two sets of Parsons type turbines, one high pressure and one low pressure set, manufactured at the Blohm & Voss Engine Works. The high pressure turbines worked two outer shafts while the low pressure cruising turbines worked the two inner shafts. There were reversing arrangements on all four shafts. The forward and aft engine rooms were divided along the centreline by a longitudinal bulkhead. Steam was fed to the turbines by eighteen Schulz, double-ended, coal-fired, water-tube boilers arranged in five boiler rooms divided down the center with a longitudinal bulkhead. The boilers were a new, high capacity type developed for the Kaiserliche Marine by Blohm & Voss. Each boiler had four water drums and two steam drums, and were made from weight-saving materials. Twin rudders were mounted in parallel, on either side of the centreline, each driven by an auxiliary steam steering engine. In the event of damage, both rudders could be coupled to a single engine, or manually operated. The turbine system was quite innovative for the Kaiserliche Marine, and rather complex in their high pressure/low pressure arrangements. But the deciding issue had been their ability to develop much greater power than triple expansion engines, which had reached the limits of development. Von der Tann was designed for 42,000shp, providing 24.5 knots.
Another view of Von der Tann passing through the breakwater. This angle gives you a different look at the arrangement of the main battery guns. German warships tended to be a bit wider amidships than ships in other navies – but that allowed for better placement of wing turret arcs of fire, room to provide more compartmentalization, and space to better protect the wing turret barbettes.
Maximum coal bunker stowage was 2,756 tons, allowing a cruising radius of 4,400 miles at 14 knots. It should be mentioned that German capital ships suffered chronic problems with the often low quality coal provided to the fleet. The “After Action” reports of Captains frequently complained the low quality coal burned poorly, generated less heat in the boilers, and produced vast quantities of thick smoke that signaled their presence to the enemy. And there were occasions when the big ships were unable to keep all the boilers fired – the coal simply didn’t burn. Accordingly, arrangements for supplemental “oil-firing” were installed in 1916, along with 180 tons of oil. “Oil-firing”, as it was called, consisted of a “sprinkler system” inside the boiler firebox that sprayed tar-oil on top of coal -- thereby lighting boiler fires more quickly – and increasing the burn rate and temperature for added speed when underway.
SHIP’S ARMAMENT
SMS Von der Tann’s forward “A” turret on the forecastle deck. Note the two anchor capstans. If you look to the right of the turret, in the base of the bridge structure, you can see the casemates for two of the 3.5 inch anti-torpedo boat guns. There are no searchlights mounted on the foremast, and the two diamond-shaped objects on the signal halyards (right and left of the upper bridge) indicate they are at anchor. Since most of the figures in the picture are wearing work clothes, I suspect they are Blohm & Voss workmen, and Von der Tann is still completing sea trials – circa 1910.
MAIN BATTERY
The main battery armament of Von der Tann consisted of the well-tested and dependable 11-inch SK-L/45 (QF) high-velocity gun. The gun came into service in 1910, specifically designed to arm the Nassau Class (sometimes referred to as the Westfalen Class) battleships. Testing results at the firing range in Meppen were so positive, they were ordered for the new cruiser as well. Mounted in twin turrets, the guns were very well placed: “A” turret (Albert) forward on the forecastle deck – “B” turret (Berta) in the starboard “forward wing” position – “C” turret (Caesar) aft, and “D” turret (David) in the port “aft wing” position. By carefully positioning the turrets and superstructure, and keeping the “deck clutter” to an absolute minimum, Von der Tann’s designers enabled her to “cross-deck fire” with the midships “wing turrets”. This gave the new cruiser a full eight gun broadside on a rather wide firing arc – something Invincible was unable to do.
I found a model of Von der Tann that perfectly illustrates the principle of cross-deck firing. Here you see both 11-inch wing turrets trained over the starboard broadside. Notice the turrets have fairly wide firing arcs – unobstructed by superstructure elements. Cross-deck fire is not recommended in all situations, or for all ships. The blast over-pressure will cause serious damage to the superstructure if the guns are too close. In some ships with light (or even medium) deck plating, the blast can buckle it as well as rip up the teak planking. Note: On this model, Von der Tann’s second funnel is painted red as a visual recognition device. Upon putting to sea, German warships painted the second funnel to ensure they did not fire on friendly ships.
The gun houses (turrets) were electrically trained, with hydraulic elevation of the gun tubes. Each turret weighed approximately 430 tons with the working chamber and lower ammunition hoists built as part of the revolving structure (sometimes called a “basket”). In effect, there were two lower hoists (one for powder and one for shells) installed on the lower platform deck that moved shells up to the revolving working chambers of the lower turret level. From there, another pair of hoists would lift the shells and charges up into the gun house. This might, at first, sound cumbersome – but this “double hoist system” prevented an explosion in the gun chamber from flashing directly down the ammunition hoists and into the magazines. It also allowed the shells to be moved more quickly, resulting in an increased rate of fire of three rounds per minute. While the arrangement did not prevent all turret fires – no German capital ships were lost to magazine explosions. (The old pre-dreadnought battleship SMS Pommern was, in fact, lost at Jutland from an explosion – but that resulted from a torpedo hit directly beneath a magazine.) Beginning with the Imperial dreadnoughts, however, it became common practice to place the magazines no lower in the ship than the “lower platform deck”, to prevent mines or torpedoes setting off the magazines. The SK-L/45 gun could fire a 670 lb armor-piercing shell out to about 19,000 yards (increased to 20,400 yards in a 1915 refit). The shell was propelled by two charges – a “fore charge” of 58 lbs in a double silk bag – and a main charge of 175 lbs in a brass case. The brass case had two advantages; the Krupp guns used a horizontal “sliding wedge breech” sealed by the rear rim of the shell casing (obturator seal) – and “cased” charges were far less likely to burn or explode in an accident. The magazines stored 165 rounds per gun.
The aft main battery turret of Von der Tann. This turret is trained over the starboard quarter. If you look past the rear of the turret, you can see the guns of the port wing turret trained over the port quarter. Looking to the right of the turret, you can just make out the guns of the starboard wing turret trained off the starboard bow. The forward turret will be trained over the port bow. This is a common combat tactic to ensure that any arc of the compass can be taken under fire immediately. Note the haze and fog making it impossible to see the horizon.
Fire Control functions were carried out from the fore or aft conning towers, whose upper floors housed the Fire Control party with Zeiss 9-foot stereoscopic rangefinders mounted on the roof. Other, smaller rangefinders were installed in various locations, and after 1914, a crow’s nest Fire Control position was added to the foremast with yet another rangefinder. All fire control stations were connected to a Central Gunnery Control situated beneath the armored protective deck. Here, the Fire Control Team received data from the remote stations, calculated target information, and issued gun-laying orders to the “Turret Captains” via voice pipes, telephones, or electro-mechanical “repeaters”. When all turrets were “ready”, the Chief Gunnery Officer would fire the desired turrets from the forward conning tower station
SECONDARY BATTERY
This is a 3D model of Von der Tann’s port side amidships. This shows the torpedo nets secured for sailing, with the booms collapsed against the ship – excellent detail – complete with the rigging for the booms. This also shows details of the secondary battery 5.9-inch “turreted casemate” guns. They are, literally, a turret shield set inside an armored casemate. Note the “dead-lights” (light shafts) embedded in the deck. You can also see the boiler room air intakes – the louvered sections around the funnel superstructure. You will be seeing this model in-game.
Unlike her British opposite number, Von der Tann followed the pattern of all German capital ships and carried a strong secondary battery. One lesson learned from the 1905 Battle Of Tsushima was that medium caliber guns were very effective against lightly armored or unprotected areas of ships – even battleships. And, at the closer range of medium-sized guns, spotting the fall of shot was not all that confusing (clearly visible difference in splash size). Ten 5.9-inch SK-L/45 (QF) high velocity, guns were mounted in MPL/06 casemates, five amidships on either beam. The guns, as usual, were mounted on the Battery Deck (main deck level) where they suffered during heavy seas or high speeds. As originally installed, they had a range of 13,500 yards, but after the action at Dogger Bank they were altered to allow a range of 16,800 yards. The gun crew of eight men had twin sighting telescopes on either side of the barrel, and could fire an approximately 100-lb shell, using a 30.2 lb RPC/12 powder charge in a brass cartridge case, at a sustained rate of 5 to 7 shells per minute. Magazine capacity allowed for 50 armor-piercing shells, and 100 head-fused high explosive rounds per gun. Each gun in the casemate battery had its’ own electric ammunition hoist.
TERTIARY BATTERY
This 3D picture shows the detail of the “notched” forecastle deck providing firing ports for the bow 3.5 inch ant-torpedo-boat guns. The guns in the bow have no shields and the hinged port shutters are shown open. Two more 3.5 inch can be seen with round shields set into the lower bridge superstructure.
For defense against torpedo boats/destroyers, sixteen 3.5-inch SK-L/45 (QF) high-velocity guns were provided. Two were mounted forward, under the bow on either side, in shuttered hull casemates, two were in shield casemates in either side of the lower bridge structure, two more were mounted in shuttered casemates on either side of the stern, while the final four were mounted in pivot mounts with shields, atop the aft superstructure. The gun fired a 20 lb shell to about 12,000 yards at the rate of 15 rounds per minute, and was crewed by three men – a traversing/elevating man – a “sight-setter” – and a loader. A total of 200 shells per gun were carried – half head-fused high explosive, and half non-fused high explosive. (A head-fused HE shell would strike light armor, activate the fuse, penetrate, and then explode. Standard HE shells would explode on contact.) After the Battle Of Dogger Bank in 1915, it was realized these light guns were virtually useless against modern destroyers, and the casemate openings in the hull were merely another place for water to enter the ship. They were gradually removed and the casemates plated over.
In this port side view, you can see how the “minimalist” superstructure was placed to great advantage. The raised forecastle deck merges into the forward bridge and funnel structure – a single funnel structure amidships (notice how the funnel housing is “angled” so as not to interfere with the firing arcs) – and the compact aft control position.
TORPEDO ARMAMENT
The Kaiserliche Marine’s tactical doctrine prior to the Great War, as envisioned by Grossadmiral Tirpitz, hypothesized the “Climactic Battle” would degenerate into a medium to short-range battle – and quite possibly a full scale melee. To take advantage of the close and brutal combat, all German capital ships carried a powerful medium gun armament and a strong torpedo armament. Von der Tann was equipped with four submerged 17.7-inch torpedo tubes – one fore and aft, and one on each beam. Eleven torpedoes were carried. The bow tube was built into a notch beneath the stem and fired directly ahead. The stern torpedo flat was on the Upper Platform Deck sandwiched between the two steering compartments, and fired directly astern from a notch cut in the centreline above the propellers. The “beam” torpedo flat was located just forward of “A” turret on the Lower Platform Deck. These torpedoes were to fire ahead with a fixed 4 degree downward tilt and an angle of 10 degrees off the ship’s beam. This was an era when the torpedo was still primitive, and gyroscopic guidance even more so – not to mention firing the torpedo into water racing past the hull at 20 knots or more. It’s small wonder they never seemed to hit anything – unless by accident.
But the reality is -- submerged torpedo tubes were more danger to friend than foe. The bow torpedo flat occupied the entire space at the extremity of the ship on the “Hold Deck”. And slightly astern of that compartment, and one deck above (Lower Platform deck), was the beam torpedo flat. This occupied the entire width of the ship as well – wider and one deck higher. (Torpedoes were long and required room to be loaded into the tube.) This presents us with two large compartments forward of “A” turret that cannot be subdivided – and the armor belt thins-out approaching the bow. If those compartments flooded – for any reason – it could seriously effect the buoyancy of the bow. In a “worst case” scenario – a mine striking the hull at that location might detonate the torpedoes – and that would be catastrophic. One wonders why so much valuable space was wasted – and such risks taken – when they were of little or no practical combat value? This was an “Achilles Heel” that would come back to haunt her sister battlecruisers.
This 3D shot shows the sharp “notch” in the forefoot beneath the bow (look directly below the second anchor) where the bow torpedo tube is. The torpedo is launched from the very bottom of the ship. If you also look at the hull bottom – just below the turret – you will see the opening in the hull for the “beam” torpedo tube. There is one on each side of the ship. This gives you some idea of how much of the bow is occupied by the two torpedo flats.
ARMOR
Due to the Naval High Command’s insistence the new cruiser be battle-line-capable, Von der Tann was designed with a particularly strong and extensive armor scheme. Her protection was only slightly less than the new Nassau Class dreadnought battleships and was based on their armor configuration. It was considered quite capable of withstanding the British 12-inch rifles and was specifically designed to be superior to HMS Invincible. In short – she was designed to survive and prevail in a slugging match.
In the Design Department of the Kaiserliche Marine, the vertical side armor of a warship was divided into three distinct elements: the “main belt” extended from a few feet below the waterline to a few feet above the waterline -- the upper belt was referred to as the “citadel armor” and extended up to the Battery Deck – and the protection from the Battery Deck up to the main Weather Deck was referred to as the “casemate armor”. Regardless of the distinction, the demarcation between belt and citadel was not as evident in Von der Tann as other German warships. The armor on German ships of the period was, for the most part, quite extensive and very thick when compared to other navies. The ship was armored with Krupp Cemented Armor, face hardened with nickel steel.
Von der Tann’s stern was unarmored up to the second longitudinal frame -- the very end only protected by the umbrella of the “protective armored deck”. From that point up to the stern barbette, the belt armor was 4 inches. From barbette to barbette, the midships was covered by a main belt of 10 inches, tapering to 6 inches at the lower edge. Forward of “A” turret barbette to the stem, the thickness was 4.9 inches, tapering to 4 inches at the bow. As was customary, the armor was mounted on a 2 inch backing of teak. The citadel armor (the next level up) ran from barbette to barbette with 8 inch thickness – increasing to 9 inches to give added protection in the area of the “wing turrets”. The belt armor on the sides was closed at the ends, similar to a box (the central citadel – stretching between the turret barbettes), with transverse bulkheads. At the very stern, the bulkhead was 4 inches, with another bulkhead at the aft barbette of 7 inches, and the bulkhead shielding the forward barbette was 8 inches tapering to 7 inches outboard.
Another view of SMS Von der Tann coming through the Cuxhaven breakwater.
The “protective armored deck”, unlike most warships, extended from stem to stern and in the vital midships area was 35 inches above the waterline. Beyond the stern barbette, the deck sloped toward the stern to just above the aft torpedo tube. Forward of “A” turret barbette the armored deck was 48 inches below the waterline and sloped downward until closed off by a transverse bulkhead. The horizontal parts of the armored deck varied considerably. Inside the midships “citadel” the deck was 1 inch thick, while astern it was 3.5 inches. Forward of the “citadel” to the stem it was 2 inches. The sloping sides of the protective armored deck were 2 inches, connected to the lower edge of the main belt armor. Armored gratings were placed inside the funnels, light shafts (“dead-lights” in the deck), and ventilation shafts.
The casemate armor covered the space between the citadel armor belt up to the Upper Deck and was 5.9 inches thick. Two 15mm thick splinter bulkheads ran behind the area of the casemate guns, with each gun separated from the others by 20mm transverse bulkheads. The casemate 5.9-inch guns were protected by shields of 3.5 inches. The 3.5-inch “ant-torpedo boat guns in the forward and aft superstructures had 2-inch shields, while the guns mounted at the bow and stern had no shields.
Von der Tann’s main battery turrets were also protected with Krupp Cemented Nickel Steel armor – turret faces 9.2 inches – sides and back 7.3 inches – sloping portion of roof 3.9 inches – flat roof 2.4 inches – inner gun house floor 4 inches. The forward turret barbette received 9.2 inches on the front – 8 inches on the side – and 6.9 inches in the rear. The stern turret barbette had 8 inches aft (on the turret facing direction) and on the sides, with 6.9 inches on the rear portion (the least likely side to be hit). The “wing turret” barbettes were a uniform 8 inches. All barbettes thinned as they reached down into the lower decks, where they were already protected by the various decks and side armor.
The forward conning tower was protected with 10-inch armor on the front and sides, with 8.9 inches on the rear. The roof was 3.5 inches. The armored shaft stretching down to the Battery Deck housed all the command elements and had 8 inches on the front and sides, and 6 inches on the rear. The aft conning tower had 8 inches, with a 2-inch roof, and a 6 inch armored shaft.
Unlike her foreign contemporaries, Von der Tann had the advantage of a built-in, armored torpedo bulkhead. This stretched from the forward barbette transverse bulkhead to the transverse bulkhead just aft of the stern barbette, with a thickness of 1 inch. The torpedo bulkhead was set inboard 12 feet from the outer hull. This space was divided in half by another bulkhead and the outer void was used as a longitudinal wing passage, while the inboard space, next to the torpedo bulkhead, was used as a coal bunker. Testing had shown that layers of coal inboard of the belt armor would absorb much of the blast and kinetic energy of shells that managed to penetrate. However, it should be noted that the protection afforded against mines and torpedoes was only marginally effective. By the time war broke out in 1914, the explosive charges of both devices had increased in size and power beyond anything anticipated by any navy.
The new battlecruiser had many carefully conceived design features that set her apart from her foreign contemporaries, but the extensive and finely-tuned armor suite was a brilliant achievement in fast capital ships. Fisher’s battlecruisers had little armor to speak of, while battleships were loaded down with the weight. But Von der Tann’s armor was balanced and carefully positioned to do the most good. Her underwater protection was improved enormously by the transverse bulkheads forming her fifteen watertight compartments. Each bulkhead reached from the keel to the upper deck and, for the most part, they had few openings. Within these large “watertight compartments” were numerous, small, watertight subdivisions (basically smaller compartments) designed to limit the degree and extent of flooding. Even her coal bunkers were incorporated into the defensive system. She was, simply put, a marvel of engineering science – and would come as a great surprise to the Royal Navy.
SMS Von der Tann is seen here, taking on coal from the collier SS Gotha while moored in Schillig Roads – circa 1913. Two Passat Class tugs stand by ahead and amidships, while an old Nordwind Class waits astern. When Von der Tann’s bunkers are full, they will warp the collier off and move to their next assignment. The battlecruiser, by Barroco Hispano – and the collier, by “AP” – make an interesting contrast. Both models are made to scale and yet, the high-sided collier towers over the low silhouette of the warship. German designers went to great lengths to make sure their battlecruisers had very little superstructure, a low freeboard, and presented as small a target as possible.
Same scene from a different angle. Note the MMP work along the sandy shore. The collier, tugs, and mooring dolphins in the picture are the work of “AP”.
From this angle, you can see the smaller and much more narrow hull of the collier beside the low, squat, wider hull of the battlecruiser. The wider beam of the warship is a deliberate design feature and provides a much more stable gun platform.
Here is a detail shot of both ships. The amount of detail on the models is absolutely amazing. And the amount of research and detail that went into “AP’s” collier is simply unbelievable. For example -- SS Gotha is flying the National Merchant Jack at the bow, with the Imperial Commercial flag at the stern. And if you look closely at the second cargo derrick, you will see the “House Flag” of the Norddeutscher Line flying at the peak.
For those of you wondering what was packed into Von der Tann’s various decks (6 in all), let’s just say that above the armored deck were the essential “services and amenities” of the warship: officer’s cabins and crew quarters – bathrooms and showers – laundry and drying areas – bakeries – several galleys and various “messing” arrangements (the Kaiserliche Marine was very “class conscious” when it came to dining arrangements). In short, the “nuts and bolts” services needed to feed and house over 900 men. Not to mention war-like things such as wireless rooms – transformer rooms – pharmacy – gunnery control apparatus – communication stations, etc, etc. Those are just a tiny sampling of all the “topside” things warships need. But below the Battery Deck, down where the light has to be electric, the world is entirely different.
Beneath the Battery Deck lies the beating heart of the ship – the boiler rooms and engine rooms – where everything is either hot and dirty, or loud and in motion. The boiler rooms begin aft of “A” turret, with three stretching back to the starboard wing turret. Here there is a narrow gap running the width of the ship to accommodate the turret barbette, magazines, a damage control room, and a battle navigation room. This is followed by two more boiler rooms stretching back to the port wing turret. Here, there is another narrow, cross-hull, gap for the barbette and magazines -- and from there back to “C” turret are the steam turbine engine rooms. Basically, almost everything below the waterline is occupied by the propulsion plant.
The beauty of the German design is that the compartment wall of all those boiler and engine rooms is the anti-torpedo bulkhead. It stretches from the forward turret barbette to the stern turret barbette -- the entire length of the engine and boiler spaces. And on the outboard side of that bulkhead is a 6-foot-thick layer of protective coal. Together with the various armor belts on the outer hull, it is one of the most efficient uses of space and best defensive arrangement of any warship.
It should be mentioned the decision to go with steam turbines was the catalyst that made the fusion of guns, speed, and adequate armor possible. The turbine installation’s lighter weight, and the lighter weight of the Blohm & Voss boilers, produced more than enough ship horsepower to carry the brilliantly balanced armor suite at the desired speed. The steam turbine installation had not been tested in a German capital ship, and had they chosen not to accept the risk – Von der Tann would have been a quite different warship.
Von der Tann was specifically designed to fight the British Invincible Class battlecruisers, and her designers ensured she would have every possible advantage – especially in “staying power”. Her armor protection was conceived to withstand the power of the British 12-inch guns, while her eight-gun 11-inch broadside was considered to be equal, if not superior, to her opponent. And Von der Tann’s beam was 8.5 feet wider, giving her significant advantages in stability, compartmentalization, and underwater protection. A simple glance at the two ship’s side armor says it all. Von der Tann had a main belt of 10 inches, a citadel belt of 8 inches, and a battery belt of 5.9 inches. The Invincible and Indefatigable Classes had a 6-inch main belt – nothing else. Within mere minutes of opening fire at Jutland in 1916, Von der Tann sent Indefatigable to the bottom in a massive explosion.
SMS Von der Tann at sea during the Great War. SMS Derfflinger can be see at left in the background. German Naval Airships (Zeppelins) were frequently used as the air reconnaissance arm of the Hochseeflotte. They could stay aloft for long periods of time and were able to fly above the ceiling of the primitive anti-aircraft guns of the day.
NEXT TIME……
THE NAVAL ARMS RACE
&
VON der TANN AT WAR
I DID TRY to keep this short, but the essential details of the design and construction were crucial to understanding the importance of this ship in the larger context.
MANY THANKS to @Barroco Hispano for his beautifully detailed warships.
SPECIAL THANKS to my collaborating partner, @AP, for his considerable hard work, dedication, and vivid imagination.
If you enjoyed anything you saw – please punch the “like” button so I will know. A comment would be even more informative.
Comments and critiques requested and gratefully accepted. All questions answered promptly to the best of my ability.
THANK YOU for your visit!
You may wish to visit these CJ’s as well……
SERIES I:
IMPERIAL DOCKYARDS: WILHELMSHAVEN
SERIES II:
IMPERIAL DOCKYARDS: CUXHAVEN
Appearing – Work In Publication
SERIES III:
IMPERIAL DOCKYARDS: BREMERHAVEN
Appearing -- ???
And please feel free to drop in at…
THE SIMTROPOLIS SHIPYARD
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