Latest posts by Matthew Wright (see all)
- Is there room for nuclear propelled surface ships? - 08/22/2017
- Project 1047 – the Dutch cruiser-killers of 1939-40 - 08/12/2017
- Battlecruisers – both over-gunned and under-armoured - 07/30/2017
The fastest battlecruisers ever seriously contemplated were the Dutch ‘Project 1047’ class of 1939-40. War prevented their design being finished, but they are fascinating examples of what could have been.
They had their origins in the naval challenge the Japanese posed by the late 1930s to the sprawling Dutch East Indies. By this time Japan had a dozen very fast cruisers armed with ten ‘Third Year Type’ 200 mm 50 calibre guns. These included the Mogami class, which began service as ‘light’ cruisers with 155-mm main guns, but were re-armed with ten 200-mm weapons. There were also four older cruisers with six 200-mm weapons, still very fast vessels. The fact that the Japanese had done all this by flouting international treaty limits did not reduce the military problem.
The Dutch answer was to re-invent the battlecruiser. The initial specification called for nine 11.1-inch guns and 33 knots in tropical waters.
This underscores one of the realities of ship design; specifications often went well beyond defining maximum potential speed. The British Admiralty, for instance, required ships to be still capable of certain speeds when some months out of dock. Further, speed was often specified as a function of displacement – a ship might have to be capable of (say) 29 knots at deep load, irrespective of the paper speed at standard displacement. All this reflected the real-world realities of ship operations, well removed from paper specifications. That did not stop reference books citing the ideal figures – or some navies exploiting the variabilities. The French and Italians were notorious for running ships light on trials during this period and reporting insanely high speeds, matching paper design, which could not be achieved in real-world operations.
In the Dutch case, the battlecruiser was specified as having to achieve 33 knots in tropical waters – conditions that robbed a steam plant of potential power, because warmer seas reduced condenser efficiency. This was apart from issues with accelerated hull (and condenser) fouling in such waters between dry-docking, despite anti-fouling treatments – something that could be remedied only by taking the ship out of service for maintenance. In any event, the tropical speed requirement implied that disproportionate weight would have to go into propulsion, compounding the usual battlecruiser problems of design balance.
The other problem was that the Netherlands had no experience of heavy ship design, so in April 1939 the Dutch Bureau of Naval Construction (Bureau Scheepschouw) turned to the Germans. However, while the Germans were happy to supply armament and armour, they were less eager to provide close details of their Scharnhorst class. Other discussions revolved around whether to use German-designed high-pressure boilers, which would have saved weight in a ship where propulsive power was priority, but Dutch designers were in doubt as to reliability. The Dutch also consulted with the Italians, where they were shown the new battleship Vittorio Veneto (although not its torpedo defence system) and given more detail of the Scharnhorst than the Germans had released.
This quest for information was to do with details; in other ways the Dutch ship – because of its speed – demanded different balances than the German battlecruiser, although they shared the same main armament. Design studies continued into 1940. Nothing had been finalised when the Germans invaded the Netherlands and work came to an end. However, in 1960, one of the designers developed a post-fact list of characteristics. This has been considered ‘definitive’, although doubtless would have been refined had construction gone ahead. One matter still under debate was speed; there was an option to drop the horsepower to 160,000, creating room for improvements in other characteristics. This would have made a more balanced design, underscoring the fact that extraordinary performance in one aspect can only be obtained by compromising others.
Sources vary – and the ‘definitive’ design remains a reconstruction. But according to an analysis by US naval architects W. H. Garzke and R. O. Dulin, the final specifications were:
Standard displacement: 28,064 tons
Full load displacement: 30,968 tons
Length (WL): 777.8’
Beam (max) 98.4’
Armament: 9 x 11.1/54.5 calibre (283 mm), 12 4.7” (120mm), 14 x 40mm Bofors, 13 x 13mm MG.
Armour: Belt (maximum) 9.84”, barbettes 9.84”, conning tower 5.12” (roof), 11.81” (walls), upper deck 3.94”, lower deck 1.18”
Speed: 33 knots (tropical waters), 34.5 knots (approx, temperate waters)
SHP: 177,538 shp (180,000 mhp)
Endurance at 20 knots: 4,500 miles
The remarkable part remains the designed speed. If the 180,000 mhp design had gone ahead, the Project 1047 type would have been theoretically capable of 34.5 knots in temperate waters.
How would they have done in their role as cruiser-killers? On paper they did not have a significant speed advantage over their intended opponents. However, even the Japanese heavy cruisers were under-armoured; and the performance of the Graf Spee‘s 11.1-inch guns against HMS Exeter at the battle of the River Plate makes clear this weapon was very effective against ‘treaty’ cruisers. By contrast, the Dutch battlecruisers had an excellent immunity zone against 8-inch fire.
If two or three ‘Project 1047’ ships had been completed, would they have made a difference? That assumes no war in either Europe or the Pacific until 1943-44. Obviously the pressures between Japan, the US and Britain would have created a diplomatic crisis at some point, even if there had been no war in Europe. But let’s suppose war was delayed and the Dutch managed to deploy two or three ‘Project 1047’ battlecruisers to Jakarta. What then? Certainly they could have tackled their intended targets. However, the Dutch ships would have been at a disadvantage fighting battleship-scale weapons; and all Japan needed to do was deploy a Kongo-class battlecruiser or two at the head of a heavy-cruiser task force.
The Dutch were not the only ones seeking an answer to Japanese heavy cruisers by the late 1930s. Winston Churchill urged the Admiralty to create modern armoured cruisers with 9.2-inch guns. During the Second World War, the US built three Alaska class, an expanded heavy cruiser with the outstanding Mk VIII 12-inch gun. And the Japanese were considering their own ‘super heavy cruisers/battlecruisers’, initially as an extension of their strategic thinking. The IJN later re-cast the design to larger scale when details of Alaska became available.
The real problem was that the nature of sea warfare was changing, and the arbiter was not the big gun, but aircraft. This made it unnecessary for nations to build ‘replies’ to foreign ship types. However, it took war experience to drive the lesson home.
Still, the Dutch ships remain one of the more intriguing ‘never-built’ designs, not least because of the extraordinary speed. No names were proposed, but given Dutch naval history it’s possible that Zeven Provincien and Batavia would have been among the candidates.
If you enjoyed this article and want to read more on naval engineering and history, don’t forget to check out my book Dreadnoughts Unleashed, available on Kindle. Click to buy.
Copyright © Matthew Wright 2017