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During the early decades of the 20th Century, this would have been a common sight in any of the industrialized nations of the world. Dreadnought battleships and battlecruisers were the largest and most mechanically complex moving objects on Earth – the most deadly that modern science could devise – and only rich and powerful nations could afford such baubles. So immense it took three or four years to build -- by thousands of workmen with heavy machines and specialized tools, who virtually hand-crafted each of the behemoths. And nations measured their wealth, power, and prestige by their possession. IMPERIAL DOCKYARDS: CUXHAVEN By: Dreadnought & AP Chapter 42: THE LAST DREAMS OF EMPIRE GROSSE KREUZER - 1914 Nine months before the contract for SMS Hindenburg was awarded to Kaiserliche Werft Wilhelmshaven, there was still great debate as to the direction the Grosse Kreuzer concept should take. At the Kaiser’s request, State Secretary von Tirpitz requested the Construction Department to prepare weight and cost data for a Panzerkreuzer with 8x14-inch guns in twin turrets. To keep the costs down, he specified that in all other respects, it was to be the same as the Derfflinger Class. But Tirpitz was still not convinced of the need for larger guns and increased displacement. In his written reply to the Kaiser, he expressed – for the first time – his reason for opposing the gun caliber increase…… “In my opinion, we cannot retain strong armor, medium artillery and large-caliber guns with the Grosse Kreuzer. We arrive at a ship of over 30,000 tons and largely eliminate the [concept of the] Grossen Kreuzer [by building a fast battleship] and threaten the Fleet Law. Perhaps the costs and ship size of the project will go on absurdum.” Not to put too fine a point on it – while the British were building larger and more powerful warships -- von Tirpitz was unwilling to challenge the Reichstag Naval Law by telling them he needed ships at least as large and powerful as the English. In 1912, Wilhelm, showing an unusual degree of clarity, was more concerned about potential future battles than the politics in the Reichstag. He instructed Tirpitz to bring the project sketches and cost data to Rominten, his East Prussian hunting lodge, on 20 August. The Kaiser, predictably, was quite taken with what was, basically, a slightly longer Derfflinger Class with 14-inch guns. Still not convinced to embrace the up-gunned cruiser, Tirpitz was, nevertheless, obliged to pursue his Sovereign’s wishes – but not with reckless abandon. Again, he ordered the Construction Department to offset the bigger guns and longer hull with tonnage and cost reductions to conform to current “battlecruiser standards”. Herr Birkner, the Chief Constructor, coordinated with the Weapons Department and the General Navy Department, and presented Tirpitz with sketches and rough figures for seven designs of comparable size and power to Derfflinger. The designs had a wide range of combinations involving 13.4-inch and 14-inch rifles, though Birkner thought the 14-inch gun rather expensive. One option included reducing the belt armor to 11 inches, while another suggested reducing the machinery -- thereby shortening the hull and lowering the cost – while sacrificing a third of a knot in speed. Though some insight was gained, the various designs “priced-out” between 54-58 million Marks – and were rejected. But this was only the beginning of a long and convoluted process. This is an early sketch plan for “Grosse Kreuzer-1914”. It most likely represents a variation of the original “A-3” design. (Margin notes on the original document reference “A-3”, but indicate the sketch has been altered – without assigning any particular designation.) The only visual differences between this plan and SMS Hindenburg is a slightly more built-up area on the lower tripod mast – and – the secondary battery has been mounted within the hull on the battery deck. (Hindenburg’s 5.9-inch guns were mounted in the superstructure at main deck level.) In early September 1912, a more detailed design, “A-3”, was worked up and presented. Based on the already confirmed design for SMS Hindenburg, the new design had the same speed, same secondary battery, and same armor suite -- but with an eight-gun 14-inch main battery. (The guns were actually 35cm in bore, which translates to 13.8 inches – but being only 7/tenths of a centimeter short of the mark – I chose “14-inch” to avoid confusion.) As a result of SMS Moltke’s recent Atlantic crossing to the United States, the new ship was designed with higher freeboard aft to keep the fantail free of water. The Chief of Weapons Department had been pushing for a larger torpedo armament and six H-8 Type torpedo tubes were planned, though the arrangement was undecided. Underwater protection was improved by extending the double bottom structure up the side of the ship to the bottom edge of the belt armor. All the additions raised displacement to 31,000 tons. A further change was made to this design and labeled “A-9” – with six guns, removing two boilers, reducing speed by a third of a knot, shortening the hull length, and now displacing 29,000 tons. The Kaiser approved the new design on 30 September 1912. Though the design elements appeared to be settled, not everyone in the Reichsmarineamt was as satisfied as the Kaiser. During the winter of 1912-1913, the Construction Department and Weapons Department jointly queried the Krupp Werft at Essen to ensure an increase in gun caliber would not delay completion of the vessel beyond Spring 1917. Krupp officials could foresee no delays – if the guns were ordered no later than April 1913. The Construction Department was concerned about the 14-inch rifles because the English, Japanese, and Russians were considering building battlecruisers mounting that caliber – while the English were going to mount 15-inch guns on their Queen Elizabeth and Revenge Class ships. The Admiralstab criticized “A-9” as under-gunned with a ridiculously over-blown torpedo armament. The Staff also believed raising the freeboard of the cruiser only created a bigger target while wasting displacement which could be applied to bigger guns and higher speed. Admiral Rollmann produced an 8 March 1913 memorandum declaring...”if the Grosse Kreuzer is to retain the right to exist...the speed of the cruiser must be maintained.” The Admiral also rejected any reduction of armor on the grounds the Kaiser would never approve. (Wilhelm favored merging the Grosse Kreuzer with the battleship -- i.e., the fast-battleship.) But Rollmann’s suggestions fell on deaf ears. Tirpitz merely pointed out there was no provision in the Fleet Law for merged ship types. Other departments again argued for a 15-inch main battery based on trends in the Royal Navy, but a cruiser with four twin turrets would displace over 30,000 tons – so that was rejected. A cruiser with six 15-inch guns in three turrets was suggested, but the majority of staff favored eight 14-inch guns. Then the discussions took an abrupt turn. This model represents the basic design concepts embodied in the proposal for a Panzerkreuzer mounting eight 14-inch guns in twin turrets. Though the design was shelved several times, it was always brought back out and tinkered with – “ad infinitum - ad nauseam”. It was nearly two years before the design reached the keel-laying stage. The picture below shows the intricate planning that went into the original design – though the various details continued to change before being finalized. The superb model of SMS Mackensen is courtesy of @Barroco Hispano. Around May 1913, the Kaiser became aware of discussions concerning 15-inch weapons, and came down strongly in favor of the larger weapon – but eight guns, rather than six. At this point, Tirpitz began to rationalize switching to the big guns. He reasoned the 12-inch gun was sufficient against British battlecruisers, but against a battleship, something bigger might be needed. Knowledge of the development of the British Queen Elizabeth and Revenge Class battleships suddenly seemed to make the need for change even more vital. It was clear the current political temper in the Reichstag would not tolerate the “fast-battleship theory”, and it was equally clear the Grosse Kreuzer were absolutely necessary to the scouting elements of the Hochseeflotte – so a 15-inch-gunned Panzerkreuzer was the only answer. By early June 1913, the first proposals for the big-gun cruiser were presented for open discussion. Designs D-47 and D-48 were, again, based on SMS Hindenburg and were virtually identical in their armor and machinery. Visually, they bore a great resemblance to Hindenburg, with the exception of the main battery turrets. Both designs had three twin 15-inch turrets -- D-47 had two superimposed forward, and one aft – while D-48 had one forward with two aft, spaced in similar fashion to Hindenburg. Both designs were flush-decked, but with a higher freeboard, as seen in previous design iterations. The new tripod foremast with gun control positions was continued, and the six torpedo tubes were also included. At the same meeting, Designs D-50 and D-51 were also presented – with the same main battery turret arrangements, but different placement of the secondary batteries. D-52, on the other hand, had four twin 15-inch turrets arranged as in Hindenburg -- but even without the higher freeboard, this ship would displace 30,300 tons and was quickly rejected as too costly. A file in the BundesArchiv, dated 6 June, showed two other design sketches using triple and even quadruple main battery turrets. But no such turrets had been developed by Krupp, so they could have been no more than mere speculation. Tirpitz strove to keep the displacement and size of the new Panzerkreuzer within limits. Designing a stable gun platform required a certain amount of width (beam) to reduce rolling in a seaway. Making a “fast” ship required additional length to accommodate additional engines and boilers. But von Tirpitz knew, there were limits to size. As Germany’s major North Sea naval base, Wilhelmshaven was subject to the considerable tidal conditions of the Jade Estuary. The harbor could only be accessed via a dredged deep-water channel, and could only be entered or exited through tidal locks designed to keep it at a constant depth of water. Regardless of what Tirpitz wanted – it had to fit through the ship locks. As can be seen, the new design is long and narrow – with a 7 to 1 length-to-beam ratio. Since the Kaiser had already agreed to the up-gunned cruiser designs, a meeting was held on 17 June to chose one. D-48 was chosen quickly (one turret forward, two aft) because it allowed the widest possible firing arcs for the guns. This design also had the aft turrets separated by the aft engine room (as in Hindenburg), which meant the two turrets and their magazines could not be disabled by a single hit. This design also had the lowest displacement – 29,600 tons. The barbette armor was thickened over that of Hindenburg and the increased engine performance was achieved by larger boilers, custom-made to more fully fit the hull spaces – while partially reducing the boiler room bunker space. “D-48a” was priced out at 55.3 million Marks and was approved by the Kaiser on 28 June 1913. (As a matter of interest – design D-47, with two turrets forward and one aft – would be resurrected in 1935 as one of several design studies forming the basis of the battlecruiser KM Scharnhorst, commissioned in 1939.) Less than a week after signing-off on the new design, the Kaiser turned up at the Admiralstab offices and found State Secretary von Tirpitz and Admiral Muller (Chief of the Naval Cabinet) in conference. Wilhelm promptly pigeonholed Muller and asked if Tirpitz shared Admiral von Ingenohl’s opinion that...”modern Panzerkreuzer were as important as battleships…” and...”whether or not in the near future a ‘battleship-Panzerkreuzer’ should be built instead?” Tirpitz – taken aback at this sudden and not so subtle hint about fast-battleships – merely looked at the two men. Rather than vent his exasperation on the Kaiser, Tirpitz looked squarely at Admiral Muller...”Would you have me throw out the Reichstag’s Fleet Law?” The Kaiser’s insistence on a fast-battleship remained in this uneasy limbo until October 1913, when outside events intruded on this thorny issue. The naval attache in London reported recent information indicating Britain was going to reduce the size of its ships in favor of an increased number of ships – all of which were to be armed with 13.5-inch or 14-inch weapons. The Kaiser, of course, took the report at face value and considered this a...”victory without firing a shot”. It was, in fact, a defeat without firing a shot. Tirpitz immediately scrapped all notions of a 15-inch weapon and reverted to the 14-inch gun. All the coaxing that had turned Tirpitz to the larger gun had been undermined by a single report – which turned out to be unreliable. While the design discussions and “delicate political maneuvers” were in progress, the lower levels of decision-making were spending their time in a more productive manner. The engineering branch of the Construction Department had recently designed and installed a successful reduction-geared steam turbine plant in the test-bed steamer Paris. Up to this point, all steam turbine installations on Kaiserliche Marine warships were “direct drive” – which did not make efficient use of the power generated. Steam turbines rotate in the thousands of RPMs, while the most effective marine propellers operate at 300 RPMs or less. In effect, a great deal of coal was burnt to generate power which simply could not be applied through the propeller. By coupling the steam turbine to a set of heavy duty, finely tooled, precision gears – the RPM speed could be reduced to a level compatible with the propeller. Engineering Branch had worked out a system with cruising turbines and reduction gearing for “Grosse Kreuzer-1914”. In each of the low-pressure turbine rooms, there would also be two cruising turbines – one high-pressure, and one low-pressure. Without getting into too many details -- the cruise turbines, linked to the reduction gearing, would power the ship up to 16 knots – after which, the main turbines (direct-drive) would take over for higher speeds. This entailed less wear and tear on the machinery and would reduce coal consumption by 33% at 14 knots, and 15% at 22 knots. The only disadvantages were, unfortunately, the expensive precision gearing and an increase in displacement. This is how SMS Mackensen might have looked upon completion. A Nordwind Class tug is moving toward the bow, while four Passat Class tugs nudge the big cruiser into her quayside berth. At 31,000 tons and 731 feet in length, she would have required five seagoing tugs to handle her in the narrow confines of a harbor. The tugs, and numerous props on the quayside are the fine work of @AP. During a 22 November meeting, by way of a comparison against D-48a, von Tirpitz presented the Kaiser with design study “D-58” – a cruiser with 14-inch guns in four twin turrets, displacing 31,000 tons. (After much “haggling”, the old Admiral had concluded anything they built was going to exceed 30,000 tons.) In one of his less “decisive” moods, Wilhelm deferred making a decision until the spring of 1914. But Tirpitz, supported by Admiral von Ingenohl, had already decided in favor of “D-58”, and instructed the Construction Department to cease all design work on “D-48a”. A week later, von Ingenohl wrote a memorandum comparing “D-48a” with a design mounting eight 12-inch guns. The obvious advantage of six 15-inch guns was the considerably greater penetration and explosive force of the bigger shell – not to mention the gun’s greater range. But there were fewer guns, and only two guns could fire directly ahead – a decided disadvantage for a reconnaissance cruiser. He included a table showing comparative values of British armor and suggested the 12-inch gun was sufficient against existing British battlecruisers, as well as British battleships launched up to 1911. But the gun was not capable of dealing with newer battleships. In terms of hitting power, Ingenohl favored the 15-inch gun – but only three twin turrets presented a problem. With salvo fire, at least three shells were required for spotting the fall of shot, and German gunnery tactics used “pairs” of turrets to produce four shells in a salvo. (You see the obvious problem.) Von Ingenohl concluded neither the 12-inch gun nor the 15-inch gun could be recommended for the new cruiser, and suggested a main battery of eight 14-inch weapons. The 14-inch shell would be more than adequate to penetrate any British armor – four guns could fire directly ahead and astern – and four twin turrets allowed for proper salvo fire. Tactically speaking, “D-58” offered advantages other designs did not. In December, “D-58” underwent further design work. The secondary 5.9-inch guns were, originally, to be mounted in the superstructure at the Upper Deck level – but they were reduced from 18 to 14 – and moved to hull casemates at Battery Deck level. Since the ship had a higher freeboard, the guns were roughly the same level above water as those in Hindenburg. Rather than a straight-line casemate, they were arranged in the “indented” style to provide a wider arc of fire ahead and astern – it also prevented a hit on a single gun from knocking out other guns by collateral damage. A proposal to reduce the main armor belt to 11 inches was flatly rejected, but the main battery turret faces were reduced from 14 inches to 13 inches (not the best idea). All suggestions for a reduction in speed were rejected out of hand, while the proposal for the turbine reduction gear was approved. To obtain a higher speed, the idea of custom-building larger boilers to fit the space available was carried forward. This avoided widening the ship’s beam to create space for additional boilers. The number of boilers was fixed at 16 -- subject to change. To create available space, the boiler room coal bunkers were eliminated, but to maintain the protection level, the coal bunkers along the side were enlarged at the expense of the wing passage voids. Extending the double bottom up to the lower edge of the main belt armor was also carried over. After the meeting, the new cruiser design was designated “D-60”. (Perhaps you are beginning to see how researchers can become confused with all these different plan designations going back and forth.) In March 1914, having studied the new plans at length, the Construction Department suggested the sloping armor (“boschung” in German) of the main protective armored deck could be eliminated. The change could be made without a significant sacrifice of protection, while it would make boiler room access to coal bunkers easier – along with other significant weight savings in altered structural details. Another savings in weight was adopted by removing the stern torpedo tube. After a further, final, meeting on 19 May, “D-60” was finalized and presented to the Kaiser, who signed-off on the design on 23 May 1914. It would be little more than a month before shots disturbed a peaceful Sunday afternoon in far away Sarajevo. This is how SMS Mackensen might have looked in 1917, moored to buoys in Schillig Roads while taking on coal and fresh provisions. Note the green channel marker buoys inshore of the battlecruiser. Mooring buoys, channel markers, tugs, and lighters by “AP”. The design for “Grosse Kreuzer-1914” was not adopted for any particular reason, but for a variety of reasons – technical, financial, and political. Despite all attempts to obtain 15-inch rifles for the new cruiser, she would be built with an intermediate gun of 14 inches, which Tirpitz knew would likely be replaced by the larger gun in the next class of Panzerkreuzer. But the naval budget of 1914 had been passed in February, and the financial resources were already all but exhausted. “Grosse Kreuzer-1914” and her three sister ships were estimated to cost, at completion, some 250 million Marks. Tirpitz knew the time was not “politically” right to raise the gun caliber and push the Panzerkreuzer into the “official” realm of the purpose-built “fast-battleship”. (The political situation would only get worse for the Kaiserliche Marine. Six months into The Great War, the Imperial fleet had delivered no significant victories and the 1915 Naval Estimates were opposed in the Reichstag.) But it was, perhaps, worth all the trouble. “Grosse Kreuzer-1914” was quite a formidable design – high speed – thickly armored – and armed with a new, “state-of-the-art”, 14-inch naval rifle (second only to the British BL 15-inch Mark I). The new cruiser could have easily disposed of any British battlecruisers then afloat and might well have been able to handle the odd battleship. Tirpitz originally planned to build a class of seven ships to this design, but the shipyards already had four battleships of the Bayern Class on the building slips, as well as (by this time) the last Derfflinger Class battlecruiser (SMS Hindenburg). With only four large construction slips available – Tirpitz had to make choices. Four ships were laid down in 1915 – while the design of the remaining three ships was later altered on the drawing board and eventually constituted a later class (Esatz Yorck Class). After the outbreak of war in August 1914, the bulk of the old protected cruisers (Victoria Louise Class) were stricken from the navy list as obsolete, while the early months of the war took its toll on the elderly armored cruisers. These actions, alone, put the Hochseeflotte at a serious numerical disadvantage in cruiser scouting forces. All four of the new “Grosse Kreuzer” were covered by the “automatic replacement” clause of the Navy Law. (It was not at all a bad deal. Old and virtually obsolete ships – no longer reasonably capable of engaging an enemy in battle – were to be replaced by “brand spanking new” Panzerkreuzer.) Various historians have come up with names for the four cruisers – none of which are in total agreement with the others. The “BundesArchiv” has some documentation on the names, but only three of the first four ships were ever christened with their official names…… Ersatz Victoria Louise…...to be named…...SMS Mackensen Ersatz Blucher…………...to be named…...SMS Graf Spee Ersatz Freya……………...to be named…...SMS Prinz Eitel Friedrich Ersatz Friedrich Carl…….to be named…...SMS Furst Bismarck (conjecture, but with documentation) Interestingly enough, the German practice of ordering a warship under an “Ersatz” name, and then christening the ship at launch with her “official” name, has not just been a matter of confusion for historians. British Naval Intelligence reports, declassified some years later (around 1965), show a great deal of information had been collected. It was, in fact, an amazingly large treasure trove of information – considering a good deal of it was obtained after war had been declared. There is no way of knowing how many spies risked their lives – and what cunning and inventive methods were employed to obtain the information – though the PBS series “Reilly: Ace Of Spies” gives us a good idea of spy craft in the Edwardian Era. But one thing is painfully apparent – the British were totally confused. In some cases, the Intelligence people thought there were actually two ships under construction – one named Ersatz Victoria Louise – the other Mackensen. This resulted in as many as 14 battlecruisers estimated to be on German slipways. In other instances, their information had the right ship, but the wrong builder’s yard. In other cases, the “Ersatz” names were not properly matched with their official names. Additional information often cited the new ships as sister ships of the Hindenburg Class – without realizing Hindenburg was actually a sister ship of the Derfflinger Class. Other ship’s data was erroneously cited as having more or fewer main battery guns than actually planned. One Intelligence report, in fact, stated the Mackensen Class was to carry 15-inch weapons. Another, rather lengthy report, reputedly sent via Sweden, listed four Manteuffel Class battlecruisers under construction. Of course, no such class was ever contemplated – but the report did contain actual blueprints of the rejected “D-48” design. And finally – at least two of the Mackensen’s were believed to have joined the Hochseeflotte before November, 1918. As you can see, historians were a good deal less confused in 1968 than the British had been in 1918. (Strangely enough – most subsequent authors have chosen to quote British sources – rather than searching surviving German archives.) MACKENSEN CLASS BATTLECRUISERS SMS Mackensen Class – Plan profile. You will notice the striking similarity to SMS Hindenburg. In essence, the class is an “improved” and more powerful version. The builder’s contract was awarded to the Blohm & Voss yards in Hamburg and was signed on 7 August 1914 – three days after Britain declared war on Germany. Blohm & Voss immediately started assembling the construction materials and began the prefabrication work. The process took a bit longer under wartime conditions, but the ship’s keel was laid on 30 January 1915. In most respects, SMS Mackensen was constructed with the same materials and with the same methods as that of previous Imperial battlecruisers – and since her design was based on the Derfflinger Class, I refer you to Chapters 15, 17, and 23 for full construction details. GENERAL HULL The new cruisers were the longest yet built at 731 feet with a beam of 99 feet, nine inches – and flush-decked like their predecessors. Their size was pushing the limit for ships that could use the III Locks at Wilhelmshaven. Their displacement, at 31,000 tons, also made them the heaviest ships yet designed for the Kaiserliche Marine – and considerably heavier than Tirpitz had originally bargained for. Mackensen’s hull was divided into 18 large watertight compartments by transverse bulkheads, with numerous smaller watertight subdivisions within each section. The new cruiser had a double bottom stretching over 92% of her length – a considerably larger area than previous Imperial warships. The lengthened double bottom was also extended as a “double hull side”, connecting with the lower edge of the main armor belt. (Designed to protect against shells falling short and striking the outer hull below the armor belt, this feature would have been of great value to Seydlitz, Derfflinger, and Lutzow at Jutland.) A surprising innovation was borrowed from the battleship USS Arkansas, commissioned in 1911 -- the “bulbous bow” fore-foot – created by the American naval architect, Admiral David Taylor. When German designers added an aft broadside torpedo flat to Mackensen’s design, they had to move the “A” and “B” main battery turrets forward to balance the center of gravity. Through “towing tank” tests, the Germans found the “bulbous bow” feature improved buoyancy forward without increasing the hull width – which would have created “drag” on the hull form. Following the developing trend, Mackensen was given a 197-foot tripod mast. A spacious fire control position was situated atop the mast legs with an additional 118-foot main mast attached to carry wireless antennas. In the primitive early days of wireless telegraphy, the taller the mast – the better the reception – and the Kaiserliche Marine was exceptionally good at intercepting and jamming enemy signals. This is a 3-D model of SMS Mackensen as she would have appeared in her final design. The battlecruiser is longer than her predecessors, and the most obvious difference from the Derfflinger Class is the Battery Deck carries the secondary battery in hull casemates, and the upper – or main deck -- has been narrowed to expose a small portion of the Battery Deck along the midships section of the hull. ARMOR SMS Mackensen’s vertical (side) armor was based entirely on that of the Derfflinger Class, to include modifications made to SMS Hindenburg, so there is no need to repeat the details, here. The basics were: bow armor 4.8 inches – stern section 4 inches – main belt 12 inches – citadel belt 9 inches – and the casemate strake was 6 inches. There were four transverse bulkheads, also armored with Krupp face-hardened nickel steel. The first armored bulkhead was 7 inches thick and located midway between the stem and “A” turret. The second armored bulkhead of 10 inches sealed the forward end of the main belt armor and fronted “A” turret. The third armored bulkhead of 10 inches was aft, and fronted “D” turret, sealing the aft end of the midships main belt armor. The fourth bulkhead was 5 inches thick, and located midway between “D” turret and the stern. Though the naval architects had, at that time, no combat results to work with, Herr Hullmann had previously pointed out the danger of the battlecruiser’s weak bow armor. Two of the four bulkheads were new additions to try and reduce the threat to the weakly armored ends of the warships. (Such an arrangement might well have saved SMS Lutzow at Jutland.) The horizontal armor on Mackensen was a considerable improvement over SMS Hindenburg, and quite extensive. The naval architects had enough foresight to increase the main gun elevation on SMS Hindenburg on their own initiative – because of the obvious advantages. And the Weapons Department was also smart enough to know the British 13.5-inch and 15-inch guns had considerable range – which meant their shells would be falling on the target from a higher and steeper trajectory – what came to be called “plunging fire”. SMS Mackensen was given a 1.5-inch Upper Deck, a 1-inch Battery Deck, and a 3.1-inch armored protective deck. It was hoped the Upper and Battery decks would be of sufficient thickness to detonate incoming shells before they reached too deeply into the ship’s interior. As the battle reports from Jutland were studied, earlier design weaknesses became apparent, and the brutal destructive power of British 15-inch shells even more so. Two inches of horizontal plate was added over the machinery and magazine spaces during construction. The protective armored deck did away with the sloping edges and tied directly into the main belt side armor. The forward conning tower was armored to 14 inches, while the aft conning tower had 8 inches. The anti-torpedo bulkhead stretched along both beams from “A” turret to “D” turret, and was 2 inches along the boiler spaces and 2.5 inches in all other areas. Three views of SMS Mackensen exiting the Inner Basin at Cuxhaven. Normally, four “fleet tugs” could have handled a ship of this size, but the German practice of mounting twin rudders on the centreline, “in parallel” (one behind the other), caused the ships to handle poorly in any shallow water and especially in confined spaces, such as harbors or canals. The more modern Panzerkreuzer were longer, and known to suddenly veer off in odd directions at slow speeds. Here you see two tugs towing, two more “riding drag” astern, and two alongside for emergencies. The shift to a 14-inch main battery necessitated an entirely new gun house design to accommodate the big rifles. The face plates were 13 inches, with 8-inch sides, sloping roof sections of 7 inches, and flat roof sections of 4 inches. The turret barbettes were 11 inches down to the floor of the battery deck, where they thinned to 3.7 inches. Thinning barbettes as they went down into the ship was a common weight-saving practice in all navies – but it was a faulty theory. Designers assumed several layers of various armor – decks, transverse bulkheads, and hull armor belts – would either detonate the shell, or slow it down sufficiently to prevent penetration if it did manage to strike the barbette armor. The battles of Dogger Bank and Jutland would prove the theory entirely bankrupt. Both British and German capital ships suffered heavily from the loss of main battery turrets – and entire warships -- due to insufficient armor on the gun houses and barbette trunks. (See related chapters on the battle.) Since the Mackensen’s were never tested in battle, we will never know if the additional armor would have been enough. But the designers had made the effort to send Mackensen into battle – without forcing her to carry the seeds of her own potential destruction. This picture has somewhat poor resolution, but it is the only one I could find showing the new SK L/45 14-inch gun – on the right. On the left, is the SK L/50 12-inch gun mounted in the Derfflinger Class battlecruisers. These guns are mounted in “test beds” which are very similar to the gun cradles found inside the turrets. Note the surprising difference in the girth and length of the two guns – as well as the ammunition displayed – and note the size of the sailor in the shot. The Krupp 14-inch gun is a veritable monster. ARMAMENT The main gun armament of the Mackensen Class battlecruisers was to be eight SK L/45 14-inch Krupp rifles. They were to be mounted in a Drh L/C 1914 model gunhouse – and in a Drh L/C 1915 model gunhouse aboard SMS Graf Spee. In most respects the turrets and mountings were very similar to the Drh L/C 1913 turrets designed for the 15-inch-gunned Bayern Class battleships. The new turrets had greater elevation and were somewhat smaller in size. (They were, in fact, larger than previous battlecruisers – but smaller than the battleship version.) Another change from previous turret designs included a “depot platform” – just below the turret working chamber -- intended to store “ready ammunition”. However, as battle reports came in from the North Sea, it was decided only shells would be stored there. The gun cradles were identical in shape to the 1913 designs, but made heavier and stronger to accommodate the more powerful guns. Each of the four gun houses had a 25-foot rangefinder located beneath the roof in its forward extremity. The original gun elevation was increased from 16 to 20 degrees, but wartime experience led to that being further increased to +28 degrees. The gun tube weight was 81 tons – roughly 30 tons heavier than the 12-inch weapons in Derfflinger – and required a more robust hydraulic elevation system with extended driving rods. At +28 degrees of elevation, the 14-inch gun could hurl a 1,321 pound shell out to 30,700 yards at a firing rate of 2.5 shells per minute. The muzzle velocity of 840mps was slower than previous German main battery weapons, but the slower shell velocity actually produced a more stable flight pattern imparting greater accuracy while reducing the “wear rate” of the barrel. With the major increase in tube weight, emergency manual elevation was no longer possible, so an auxiliary electric drive was installed, while the gunhouses were traversed electronically. In an attempt to reduce the overall weight of the turret and working machinery, only a single munitions hoist was installed for each gun. This meant both powder charges and shells were carried in the same hoist. This was roughly the same hoist system installed in Lutzow and Derfflinger – but without the usual interruption between magazine and gun house. This was a most unusual choice for the normally safety-conscious German designers. But using an uninterrupted hoist directly from the magazine to the gunhouse did not appear to entail any undue hazards. Automatic flash doors were installed at both ends of the hoist to prevent accidents, as well as special flash-proof scuttles on the powder magazines and shell rooms. The shells came up from the magazines and exited the hoists between the two guns, where an automatic rammer pushed them onto a “munitions car” – the car was automatically transported behind the guns, where they were rammed home by another automatic rammer. The control position for the loading machinery was in the rear of the turret and had a clear view of the entire operation. Each gun tube was supplied with 85 shells – a mixture of high-explosive, or aluminum-capped armor-piercing. Two smoke extraction fans were installed in the rear of the turret, exhausting the fumes through an armored grate in the floor. The main battery turrets were arranged with excellent arcs of fire – 300 degrees for “A” and “B” turrets – with 310 degrees for “C” and “D” turrets. The Artillery Transmitting Station (fire control central) was located deep within the hull on the middle Platform Deck. The secondary battery consisted of 14 SK L/45 (QF) 5.9-inch guns mounted within hull casemates – 7 on each beam. The casemate area stretched from the rear of “A” turret to the rear of “C” turret – much farther forward than in previous battlecruisers. The German 5.9-inch was an excellent gun and quite capable of dealing with destroyers, and even light cruisers. (See Chapter 17 for details on gun performance.) The light artillery (anti-aircraft weapons) were the standard 3.1-inch Flak L/45 in the MPL C/1913 mounting. These were grouped with four around the forward bridge and four more around “C” turret. The guns were supplied with 450 rounds apiece. Again – the small number of anti-aircraft guns were more than sufficient to deal with the nearly harmless aircraft of the period. The torpedo armament had been increased at the insistence of the Weapons Department, but was reduced to five tubes when the stern torpedo compartment was eliminated to make room for the rudder steering system (itself moved to make room for the new geared turbines). One torpedo tube was mounted in the bow, one on either beam just forward of “A” turret, and one on either beam just aft of the “D” turret magazines. All tubes were equipped with the new quick-loading system and would fire the H-8 Type torpedo. This weapon had two optional speeds and ranges – 6,600 yards at 36 knots, or 15,300 yards at 30 knots. Here we see two of the four Mackensen Class battlecruisers tied-up at mooring points in the Cuxhaven roadsted. SMS Prinz Eitel Friedrich is moored inboard, and SMS Graf Spee is outboard, preparing to take aboard fresh provisions, stores, and coal. The mooring points are by “Mattb325” – modified for use in Cuxhaven. The two wonderful battlecruisers are by @Barroco Hispano. The white tug was gifted by “WolfZe”. Breakwaters by “Uki”. The sailors, lighters, boat boom, small boats, and Thor Class tug are the meticulous work of @AP. In the lower picture you can clearly see where the new 25-foot, internal rangefinder is mounted at the forward extremity of each main battery gunhouse. Close-up detail shot. MACHINERY As with previous Panzerkreuzer, SMS Mackensen was powered by marine steam turbines. Two high-pressure turbines drove the outer shafts through “direct-drive”, and were located outboard on either side of the “C” turret magazines. Low-pressure turbines drove the two inner shafts and were located in the below-decks space between the two aft turrets. The ship’s main condensers were also housed in the aft turbine rooms. For the first time in a German capital ship, “cruise turbines” were coupled to the inner shafts. A high-pressure and low-pressure cruise turbine was coupled to a reduction gear, which was, in turn, coupled to each inner shaft. SMS Mackensen, Graf Spee, and Ersatz Freya were to receive this arrangement, while Furst Bismarck was to be fitted with Professor Fottinger’s recently tested hydrodynamic transmission. (Fottinger’s transmission was slated to be used with the following Ersatz Yorck Class battlecruisers, but in the end, it never saw service in a commissioned capital ship. The system was tested in one of the pre-war German passenger liners, which was ceded to Britain as war reparations. They yanked the system out in 1926 and replaced it with a standard turbine arrangement. But there must have been some merit to Fottinger’s system -- it eventually led to the automobile automatic transmission.) In the final design, Mackensen’s boiler plant comprised eight oil-fired boilers and twenty-four coal-fired boilers. In a slightly improved pattern, there were four smaller boilers in each of the watertight boiler rooms (easier to fit into tight spaces). This was also in line with the Imperial Navy’s policy for a more uniform method of generating steam. It also allowed for boilers to be held in reserve, and made provision for “boiler rotation” during prolonged high-speed operation (for cleaning and trimming the fires -- a problem encountered at Jutland). Contemporary design detail sketches show the coal-fired boilers to be a custom-built double-boiler type. The new cruiser was designed with the standard four-shaft, twin rudders in-parallel, configuration – each rudder operated by a steam-powered spindle drive. In the event of a steering engine failure, the rudders could be cross-connected or operated manually. Mackensen’s bunker capacity was 4,000 tons of coal and 2,000 tons of oil – giving a theoretical operating range of 8,000 miles at 14 knots. The ship’s propulsion plant had a designed rating of 90,000shp capable of achieving 28 knots. GENERAL CHARACTERISTICS SMS Mackensen’s electrical plant was more extensive than her predecessors – eight diesel dynamos – the diesels variously built by Blohm & Voss, M.A.N., and Germania-Werft. With eight dynamos provided by Siemens Schuckert, AEG (General Electric), and Brown-Boveri & Co. The system operated on 220 volts with a total output of 2,320kw. Among other equipment, the diesel-dynamos powered nine 48-inch searchlights – one on the upper tripod mast -- four mounted on the forward searchlight bridge – between the fore funnel and the tripod mast. The other four were on the aft searchlight bridge between the mainmast and the second funnel. This view from the stern shows the grouping of the aft anti-aircraft guns on the main deck around “C” turret and a good look at the newly configured aft searchlight bridge. You will note the tight grouping of the “no frills” superstructure and the clutter-free decks. Drainage and pumping systems for the Mackensen Class were completely redesigned from that of previous battlecruisers. Instead of the old “closed-loop”, the new system was a “group-drainage” type – where the transverse bulkheads divided the ship into sections independent of one another. Each watertight compartment and all of its subdivisions were drained through a common pipe, which in turn, could be connected by a valve to the adjoining watertight compartments. In theory, this prevented flooding in one watertight section from overwhelming the pumps in another section. In an emergency, the ship’s condensers, auxiliary cool water pumps, and engine cooling water pumps, could be linked to the system for added capacity. There were eight drainage pumps instead of the usual five. Her crew complement called for 46 officers and 1,140 enlisted men. In all other respects, the Mackensen Class would have had the same details and arrangements as the Derfflinger Class. At this point it might be worth studying the two ships to see just how similar they really were…… Derfflinger is in the foreground, with Mackensen behind her. Mackensen’s extra 41 foot length is apparent. The forecastle ahead of “A” turret is longer, as is the fantail aft of “D” turret – while her midships between the gun turrets is shorter than that on Derfflinger, and her taller funnels are grouped closer together. Mackensen has a more spacious navigation bridge and armored conning tower. While Derfflinger’s forward bridge is lower, and less cluttered – Mackensen’s is more built-up, taller, and has a tripod mast and designated searchlight bridge between the conning tower and the first funnel. The distance between the “C” and “D” turrets is greater on Mackensen than on Derfflinger. SMS Mackensen is in the foreground of this close-up, which shows the individual details much better. “C” turret has two large air scoops on either side, leading down to the high-pressure turbine rooms on either side of the turret magazines. The below-decks space between “C” and “D” turret is occupied by the low-pressure turbines, cruising turbines, and reduction gearing. Mackensen’s gun houses are much larger than those on Derfflinger, and have adopted sloping armor to reduce the vertical and horizontal surface areas of the turret roof and sides. The fronts of the turrets have an unusual “protruding wing” which was specifically included to house the new 25-foot rangefinders used for “local control” in emergencies. Yes – you could tell the two ships apart with no difficulty. But if you examine the deck layout as separate components – the two ships are remarkably similar. The turrets are placed in similar fashion. The conning tower, bridge, and first funnel form the same component structures in both ships (Derfflinger even received a tripod mast after Jutland.) The midships section is again mostly devoted to the ship’s boats. And the aft control structure and funnel on both ships are very similar. The structures are a bit smaller, or a bit larger – but they are basically the same. A sailor transferred from Derfflinger to Mackensen would have felt right at home. MACKENSEN CLASS: Mackensen – Graf Spee – Prinz Eitel Friedrich – Furst Bismarck 31,000 tons – 731 feet in length – 28 knots – 8x14-inch guns – 14x5.9-inch guns – 8x3.1-inch guns – 5x23.6-inch torpedo tubes – Belt armor 12 inches. CONSTRUCTION The keel of this magnificent warship was laid on 30 January 1915, at the Blohm & Voss shipyards in Hamburg. Imperial Germany was only 6 months into the war, and the staff at the Admiralstab were just beginning to find out how ill-prepared they were. Only a little more surprised, were the members of the Army’s Great General Staff. During the first few weeks of the war, the German Army had advanced from success to success, and the army commanders and the General Staff were elated. But as the weeks turned into months, the enemy’s resistance stiffened, and German casualty rates became alarming. Pre-war staff exercises and wargames had never anticipated the sheer slaughter of a machine-gun-dominated modern battlefield. The Army had been in heavy combat from the start -- and was not only in need of replacements for their thinning ranks, but was burning through vast quantities of ammunition, supplies, and equipment of every description. Factories all over Germany were swamped with new contracts demanding huge quantities of uniforms, boots, weapons, and especially machine guns – but most especially for the monster cannon from the Krupp Works. And even at this early stage of the war, the factories and the farms were beginning to lose their unskilled workers to replace battlefield losses. The Kaiserliche Marine also suffered shortages they had never anticipated. Before the war, the fleet had been chronically short of crewmen to man the new dreadnoughts – but that had been more a shortage of money to pay them. Now, the Army was taking every able-bodied man they could and naval recruits were scarce. Soon, the Admiralstab would have to decommission their elderly ships so they could assign the crews to actual fighting ships. Construction yards were overwhelmed with orders for additional torpedo boats to screen the fleet – for minesweepers – and for submarines to attack the English. Dockyards were filling up with damaged warships of all sizes – dreadnoughts torpedoed by submarines – light cruisers struck by mines – or torpedo boats peppered with gunfire while skirmishing in the German Bight or the Baltic Sea. Worst of all – the ranks of the dockyard workers were being thinned by conscription into the Army. Suddenly there was more work than the yards could handle – and fewer workers to handle it. SMS Mackensen fell prey to every shortage and delay imaginable. Within weeks of the keel laying ceremony, the decision was made to slow down her construction so Blohm & Voss workers could be switched to repairing battle damage from light forces skirmishing in the North Sea. Several months later, more workmen were reassigned to begin construction on new U-Boats urgently requested by the Admiralstab. Soon thereafter, Krupp Werk in Essen let it be known priority demands for Army heavy artillery would slow the delivery of Mackensen’s big 14-inch guns. (Eventually, all of her gun tubes were commandeered and mounted as railway guns for the Western Front.) The hull of (arguably) the most advanced warship ever designed for the Imperial Navy remained on the builder’s slip for all of 28 months. Easily a year past its due-date. SMS Mackensen, officially christened, slides down the builder’s slip and into the construction basin at Blohm & Voss Dockyards. She is over a year late getting into the water. You can just make out the shape of the new “bulbous bow” around the “cut” of the “forefoot”. On 21 April 1917, the new battlecruiser was christened by the wife of Feldmarschall August von Mackensen – the man for whom the ship was named. Feldmarschall Anton Ludwig Friedrich August von Mackensen – 1849-1945 – was born in Saxony and joined the 2nd Hussar Regiment of the Prussian Army at age 19 in 1868. He fought in the Franco-Prussian War of 1871 and rose to command the 1st Hussar Regiment in 1893. During The Great War he commanded the 9th and 11th Armies with distinction and was promoted to Feldmarschall in June 1915. He participated in the conquest of Serbia and Romania and was appointed military governor of Romania in 1917. August von Mackensen retired from the Army in 1920, but remained politically active until his death in 1945, at age ninety-five. The unfinished hull of SMS Mackensen was moved into the fitting-out basin, but by 1917 the war aims of the Kaiserliche Marine had changed. The Hochseeflotte had only managed a “tactical” victory at Jutland, while narrowly avoiding a disaster. It was clear to the Admiralstab that even a strengthened battle fleet would not be enough to achieve a decisive victory over the British. The Imperial Navy would now rely upon its U-Boats, mines, and light forces to confront the English across the North Sea. Continuing to build massive capital ships, with no hope of producing a victory, would merely waste valuable resources needed by the fleet – not to mention the Army. A fitting-out gang of around a thousand workmen were allocated to the new Panzerkreuzer and work proceeded slowly. When the Armistice was signed in late 1918, some fifteen month’s work remained before completion. The newly formed Wiemar Republic had no interest in finishing the vessel, and on 17 November 1919, SMS Mackensen was stricken from the naval register. On 21 October 1921, the unfinished hull was sold to Fa Kubatz of Hamburg for scrapping – which was carried out in Kiel beginning in 1922. SMS GRAF SPEE The keel of Graf Spee was laid on 30 November 1915 at the Ferdinand Schichau Werk in Danzig, and she was launched nearly 22 months later, on 15 September 1917. The christening speech was given by HRH Grossadmiral Prinz Heinrich, Commander Baltic Forces, and the ship was christened by the widow of Vizeadmiral Graf von Spee, Grafin Margarette von Spee. She brought a bottle of vintage white wine from the family estates in the Rhineland for the purpose. The ship’s namesake was Vizeadmiral Graf von Spee, born in Copenhagen in 1861, to traveling parents with roots in the Rhineland. Young Maximilian joined the Imperial Navy at age 17, and over the years held several seagoing commands, including the cruiser Hela and the pre-dreadnought battleship Wittelsbach. He did two tours on the Reichsmarineamt staff, and held appointments as second in command of Scouting Forces, and second in command III Battle Squadron, before being appointed to command the German East Asiatic Squadron in China. He and two of his sons perished when his flagship, SMS Scharnhorst, went down at the battle of the Falkland Islands, 8 December 1914. (See Chapter 09 for full details.) SMS Graf Spee was to have been finished as a flagship, with quarters and amenities befitting an admiral and his staff. But no admiral would ever serve in her. Graf Spee suffered much the same fate as Mackensen. She was struck from the ship register and sold for scrap on the same day as her sister ship. She was broken up between 1921-1922 at Deutsch Werke on the Nordmole in Kiel. SMS PRINZ EITEL FRIEDRICH The ship’s keel was laid at the Blohm & Voss yards on 1 May 1915. The work progressed slowly from the start – until it stopped entirely in the summer of 1917 – some 21 month’s work remaining. Never launched, she was not christened – but the name can be found on official correspondence in numerous places. As her predecessors, her name was struck from the register of ships on 17 November 1919, but she remained on the building slip until launched on 13 March 1920 – to clear the slip for other work. The unfinished hull was sold to Fa Kubatz in Hamburg and was broken up between 1920 and 1922. “The remains of Glory” – circa 1921. In this quiet backwater of the Blohm & Voss dockyards lies the residue of a mighty fleet. At lower left, moored along the quay, is the unfinished hull of SMS Prinz Eitel Friedrich. Alongside is the unfinished 15-inch-gun Bayern Class battleship, SMS Wurttemberg. On the right is her unfinished sister-ship, the 15-inch-gun SMS Sachsen. Also visible in front of the big liner on the left is a pair of floating “masting sheers” – often used as a cheap alternative to cantilever cranes. At the end of that line of ships can be seen a large floating dock – even these would be turned over to the “victorious powers” as war reparations. (Note the line of “mooring dolphins” in the center of the basin.) SMS FURST BISMARCK The contract was awarded to the Imperial Dockyards Wilhelmshaven on 18 April 1915, followed by the keel laying on 3 November 1915. She was intended to replace her namesake – the first armored cruiser commissioned into the Kaiserliche Marine in 1900. By the time The Great War ground to its bitter end, the new cruiser was still twenty-six months from completion. Struck from the lists along with her sisters, Furst Bismarck was broken up on the slip, the job finished by 1922. The following four pictures show “what might have been”. Had things gone according to plan, this could have been a typical scene in mid-1918. Three battlecruisers performing “picket duty” in Schillig Roads. Front to back – SMS Moltke, Derfflinger, and Mackensen. But “plans” are only dreams – and not all of them come true. (Battlecruiser models courtesy of @Barroco Hispano. Mooring buoys, tugs, lighters, and channel marker buoys are the work of @AP) The Mackensen Class ships were not the last battlecruiser designs considered by the Imperial Navy, but they were the last ships to even come close to being a reality. At 31,000 tons, they would have been the largest capital ships afloat. The British built faster battlecruisers, but nothing that could have stood up to Mackensen’s 14-inch guns and superb armor suite. And it should be remembered – Beatty’s battlecruisers at Jutland were fast, but that did not save them from taking a severe pounding. It had taken many years and much discussion, but The Imperial German Navy finally produced a capital ship design that was, in almost all respects, superior to their British opponents. It was true – they had declined to mount 15-inch rifles – but the 14-inch shell possessed much greater penetration and a significantly increased bursting charge over that of the 12-inch. The German’s superior gunnery skills would have more than offset the difference. They were handsome warships – long and low – with a towering tripod mast and more closely grouped funnels. Their clean lines bespoke the high speed of powerful engines – and the large, squat, turrets with their massive guns clearly showed her destructive power. Had the Mackensen’s been commissioned, they could well have been the perfect battlecruiser / fast-battleship. If proof is needed of the German ship’s power -- when the British obtained particulars of their design, they countered by laying down the four battlecruisers of the Admiral Class. As The Great War approached its close, three of the British battlecruisers were canceled, and the fourth one was not commissioned until 1920. But she was known the world over as...”The Mighty Hood”. HMS Hood at anchor in the Solent, circa 1924. NEXT TIME…… THE PIPE DREAMS MANY THANKS to @Barroco Hispano for his beautiful warship models. SPECIAL THANKS to my friend and partner, @AP, for his talents, meticulous models, colorful imagination, and extreme dedication. If you enjoyed anything – please punch the “like” button so WE will know. A comment would be even more informative. Comments and critiques requested and gratefully accepted. All questions answered promptly to the best of our 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 https://community.simtropolis.com/forums/topic/761469-simtropolis-shipyard/?tab=comments#comment-1766496