Interwar Cruiser Submarine Design Challenge

here is the result of studies for a large submarine cruiser (even raider cruiser) made by Galeazzi, one of the main italian designers in the interwar period.

[ img ]

Statistics
Displacement:
-3,800t surfaced
-5,275t submerged
Dimensions:
-L 122.5m
-B 10.5m
-D 5.9m
Performance:
-24 knots surfaced
-9.5 knots submerged
-12,000nm @ 10 knots on the surface
-19,000nm @10 knots on surface (overloaded)
-80 nm @ 4 knots submerged
-Max depth: 150m
-Test depth: 200m
Manning:
-12 Officers plus 22 Subofficers
-80 Enlisted
Armament:
-8x 533 mm TTs (20 torpedoes)
-4x 152/50
-2x 76/50mm AA

Hangar for 1 airplane

-So here's my entry:

As many of you know I was running the William Walker's Nicaragua AU a while back and it has been inactive for a while. I have been working on rebooting it and this is part of that attempt.

-Towards the end of the First World War, the Nicaraguan fleet was looking for large, modern submarines that could patrol long distances around the Atlantic, and issued a requirement to several bidders in 1917. However, no design really appeared to fulfill all the requirements until the French builders at the Arsenal de Cherbourg (the same yard that built the cruiser submarine Surcouf in 1926) submitted a design in 1927. By this time the nation had reduced its navy budget and manpower allotment considerably, and had no need for new warships. Thus, the design was not adopted for service, and it would be 1935 before submarines for the navy were ordered.

-They were to be armed with a pair of 15cm. SK/L45 guns captured from Germany during the First World War. The guns were seized by the French during the war reparation process, and were planned for an additional unit of the U-139 class large submarines, but were never mounted. The rangefinder for the deck guns was mounted on a platform built onto the aft of the sail, and the ammunition could be handled by a pair of deck cranes. In addition to these guns, 6 torpedo tubes were planned for the class, 4 in the bow and 2 in the stern. No anti-aircraft armament was fitted in the initial draft. Net-cutting gear was to be fitted on the bow, as was a wireless radio set with the antennas suspended between the two small masts.

-The class was to be propelled by 2 Sulzer diesel engines and 2 Siemens electric motors driving 2 shafts. Surface speed was estimated at 12 knots, while submerged they were intended for 8. Her unique rounded conning tower was intended to aid streamlining and improve her submerged speed.

--COMMENTS AND QUESTIONS WELCOME--

_________________
Best regards,

RegiaMarina1939

Hi, Charguizard. The range is somewhat modest for a cruiser submarine: in surface 11,000 miles at an economic speed of 9 kts, at 17.5 kts the range was only of 3500 miles. But the sumerged range at slow speeds (under 3 kts) was of more than 100 miles, a good achievement for the era.
I thought in a rather modern propulsive arrengment: The Sulzer diesels were compact, but for the power output, the smaller 600 hp engines were even more compact! The final drive is coupling the screws shafts directly to the electric motors, and each diesel to an alternator. This arrangement is less cramped than the mechanical geared final drive. The main concern is that I don't know if this solution is available in the 30s for a submarine (but it was known for surface vessels or even, trains!). Cheers!

The V-78 class of two submarines served the basis for Antaran fleet boats, with the only noticeable differences between subsequent classes being the removal of the 155mm gun in place of the more favourable and lighter 100mm and 127mm gun. The V-78 class carried 20 torpedoes including reloads.

Displacement:
1 289 t light; 1 326 t standard; 1 610 t normal; 1 838 t full load

Dimensions:
-Length 125m
-Beam 9.5m
-Draft 5m
Performance:
-25 knots surfaced
-9.1 knots submerged
-15,000nm @ 10 knots on the surface
-Max depth: on average 160m
-Test depth: 180m
Manning:
-10 Officers
-74 Enlisted
Armament:
-155mm/60 Mk14 with 90 rounds
-Twin 20mm/60 NM

_________________
Best regards,

RegiaMarina1939

Displacement:
~4,100 tonnes surfaced
~4,600 tonnes submerged.

4 x 6400 hp steam turbines for ~25 knots surfaced, 2 x 2400 hp electric motors for ~9.5 knots submerged. 2 x 500 hp diesel generators for battery charging.
10 x 550mm torpedo tubes, 20 reloads.
4 x 140mm SP guns w/2500 rounds.
2 x 84mm AA guns w/300 rounds.
Test depth 90m.
Range of 25,000 km @ 10 knots surfaced, 130 km @ 4.5 knots submerged.
Upper hull armoured against destroyer-calibre gunfire w/90mm plating.

One specially designed watertight semi-submersible cutter carried in a pocket forward, able to be launched with boarding party already aboard while at periscope depth. One floatplane carried disassembled.

Crew of 109 officers and enlisted.

A follow on from the 1913 Vickers-Kaurna project for a steam powered submarine, (the Artemisiya), these much improved versions kept the high surface speed of the class, but fitted their boilers inside separate pressure hulls, permitting free-flooding of the boiler rooms, as well as keeping the crew safer from dangerous heat-buildups in the tropics. Two flotillas were built in the early 1920's, only to fall victim to the First London Naval Treaty's ban on large submarines.

An interesting design to be sure, but I don't see anything that changed from the original drawing besides the color and a few details. If anyone is still making an entry do let me know, because soon we will start picking judges over on discord and start going over the submissions.

_________________
Best regards,

RegiaMarina1939

A steam powered submarine in midwar period seems very curious to me. She was designed to have great range (and very high surface speed to follow rest fleet), but the curiocity of the design remains.

All entries are very well drawn.

I was going to draw a submarine, but nah. it would differ to much, compared to any other submarines, it would just be a standard submarine that are over shy of 100 meter, with some deck guns and the Norwegian party trick: 2+ more torpedo tube than normal, these more tubes thes better...

edit:
I take a shower, then I shall just put something fast together... will not be high quality drawing

Regardless of the quality, I am interested to see what you have in store for us, huehuen!

_________________
Best regards,

RegiaMarina1939

Shipbucket

Who is online