French submarine Surcouf©Warshipsresearch.blogspot.com
British submarine HMS X-1©Warshipsresearch.blogspot.com
On the frontpage of the The Duisburger General-Anzeiger dated Monday 17 January 1921 was article published titeld Das U-Boot der unbegrenzten Möchlichkeiten [roughly translated the submarine of the unlimited possibilities]. The reporter wrote that thanks to the reseach of Flamm (1) naval war was to be changed radically. The size of the submarine was no longer limited and to be armed with armor protected heavy guns. Flamm developed a new stapbility principe after many years of intensive research allowing him to build much larger submarines. At that moment he designed an amored U-boot cruiser of 1,433 tons with a 35mm thick armor weighing 134 ton and an area of 750 square metres. At both ends of the deck was an armored gunturret positioned with a 10.5cm gun. Also on deck were rotatable torpedo tubes mounted, and under deck were fixed tubes built-in. Surfaced speed was 17.5 knots. Nearly completed were the plans for a submarine of 4,870 tons with a length of 100 metres. She was to be armed with 4 smaller or two 21cm guns mounted in 2 armored gun turrets like the earlier mentioned design. Speed was increased to 25 knots. Further more he was working on a concept for a submarine of 8,400 or 9,900 tons which was to develop a speed of 28 knots. She was to be protected by 6-7cm thich armor plates and to be armed with four 21 or 24cm guns, again mounted in armored turrets.
The magazine Die Umschau volume 25 No. 6 dated 5 February 1921 p. 74 reported that Flamm, professor at the Charlottenburger Technischen Hochschule succeeded in designing a submarine which was armoured without negative effects for the stability while diving or submerged cruising. Until then was the danger of turning around the main objection against the use of armour. There were project drawings available for an armoured submarine cruiser of 1,443 tons volume content and with a speed of 17.5 knots. Patents were obtained in the United Kingdom, The Netherlands and Italy and negotiations went underway in the USA.
The Time Magazine (topic The Machine Age dated 4 February 1924) wrote that the Maschinenfabriek Augsburg-Nürnberg AG (MAN) made a model of a submarine cruiser of more as 7,000 tons and supplies. Interesting details are supplied: "The boat is heartshaped, point upward, with the keel in the groove of the heart, like an inverted V. The principal advantage is rapid and even submersion, the stability depending on the form and the distribution of pressure. It can submerge in 30 seconds without turning a degree, can cruise 20,000 miles and develop a speed of 23 knots an hour. It is 525 ft. long and 49 ft. wide, and carries large torpedo and gun armament."
The Karlsruher Tagblatt dated Wednesday 23 April 1924 published on page 6 an article dealing with the submarine cruiser war of the future which were without any doubt to become of the most dangerous weapons in a future naval war. USA, England and France showed signifant interest in building such submarines. An absolute independence of submarine support points excluded the submarine home base or an unlimited range as proposed in Flamms designs was yet not realized. He designed two twin boats namely a submarine cruiser of 7,067 tons and a submarine minelayer of 7,700 tons displacement. Both types had the same speed and diving qualities to able the boats to cooperate closely.
The submarine cruiser would have a length of around 403 feet. Deck and sides were heavily armoured against air attacks. The deck armament included 2-21cm guns and some 60 calibre guns met sufficient ammunition storage. In the First World War was the calibre maximum 40-calibre. In the bow and stern were 4 torpedo tubes fitted for which 45 torpedoes were carried. Until now was that just six torpedoes. The diesel propulsion delivered 30,000 allowing a surfaced speed of 22-23 knots possible. For submerged cruising was a 5,000hp electric engine available. Crew numbered around 100 men. Dive time 1 minute. Building time around 9 months and costs around 40 million mark.
The Australian newspaper Northern Star dated Saturday 10 January 1925 referred to an article recently published in Marine Rundschau dealing with the designs of Flamm. Despite his opinion that battleships and other types of surface warships were still indispensable, he thought that submarines ought to have a higher place in naval warfare in the future. Key word in his research was supreme importance of stability in submarines which he wanted to ssolve by adopting a new hull form. This form supplied a perfect stability while diving “and when running submerged, continues to steadniness of trim, and enables relatively enormous weights to be carried on the upper part of the hull.” As far as he known other navies depended for the stability of their 4,000+ tons submarine cruisers on ballast or deadweight to carry. If ballast was not used for assuring the staibility they should use his system of construction and which was patented world wide. Since 1919 he was doing intensive research in this matter.
One of his projects was a diving cruiser of 7,067 tons displacement fitted out with defensive armour with a weight of 614.5 tons and armed with turret guns, quick firing guns and torpedo tubes with a weight f 500,5 tons. The idea behind this design was ‘that such a vessel mounting one or more heavy guns in deck turrets and having its sides plated with armour, could rise to the surface and, with only its upper works showing, canonnade with deadly effect the unarmoured sides of an enemy dreadnought. The submarine itself would present an almost invisble target, and could only be hit by chance.”
The American magazine Popular Science dated 1927 reported that the French navy completed the largest submarine of the world with a tonnage of 3000 tons. This was the Surcouf (2). Flamm planned a much larger submarine cruiser which had a tonnage of 7,067 tons, a length of 403 feet and which was armed with 2-8” guns. The British Royal Navy had the X-1 (3) of 2,780 tons, a length 351 feet and which was armed with 4” guns and 21” torpedo tubes and able to remain 2.5 day submerged.
Notes
1. Oswald Flamm (30 July 1861 Düsseldorf, Germany-12 June 1935 Berling, Germany, Berlin) shipbuilding and -engine engineer. Played an important role in the German shipbuilding and was specialised in screws. stability and submarine building. He was according to Time Magazine (website Time.com) reponsible for a “series of revolutionary, non-patent designs for heavily armored, giant submersible dreadnought and u-boat cruisers between 1921 and 1930.”
2. Ordered on 4 August 1926, laid down by Cherbourg Arsenal on 1 July 1927, launched on 18 November 1929, commissioned ion 16 April 1935, refitted in 1941 and disappeared on 18 February 1942. Pennant N N 3 and designation number 17P. Displacement 2,926 (dead)-3,302 (surfaced)-4,373 (submerged) tons and as dimension 361 x 29.6 z 23.9 feet or 110 x 9 x 7.25 metres.
3. Laid down by HM Dockyard, Chatham, England on 2 November 1921, launched on 16 June 1923, completed on 23 September 1925, commissioned in December 1925, partof the reserve since 1930 and broken up on 12 December 1936. Displacement 2,820 (surfaced)-3,700 (submerged) tons and as dimensions 363.6 x 29.9 x 15 or 110.8 x 9.1 x 4.6 metres. Armed with 6-53.3cm/21” torpedo tubes in de bow and 2x2-13.2cn/5.2” guns.
Sources
Trove website Australian newspapers.
German Digital Newspapers Archive
Delpher.nl
New Zealand Historical Newspapers Papers Past
