USN Cruiser Submarines (1919-1920)

[lordroel]

So found this on the link below, what if you where a US  Navy admiral and had to pick on of the four designs, which would you pick to be build and when build would they still be in service when World War II broke out. 

Inormation comes from Naval History and Heritage Command - Cruiser Submarine

S-584-163 "Cruiser Submarine Type 1--Unprotected"

Preliminary design plan for a Cruiser Submarine (Type 1 Unprotected). The Chief of the Bureau of Construction and Repair requested in early October 1920 that his staff develop a set of comparative studies for ships of this type, apparently reflecting his desire to anticipate a possible need for large submarine scouts. The vessel was intended to carry heavy guns and scout aircraft, and be able to submerge to great depths. Type 1 emphasized gun armament and speed and had no protection and large aircraft storage tubes topside that the Bureau considered a risk to survival if flooded. The concept was not pursued. This plan provided eight 8-inch guns, diesel machinery, and a surface speed of 14 knots in a ship 400 feet long on the waterline, 46 feet in beam, and with a normal surface displacement of 10,000 tons.



S-584-166 "Cruiser Submarine Type 2 -- Armored

Preliminary design plan for a Cruiser Submarine (Type 2 Armored). The Chief of the Bureau of Construction and Repair requested in early October 1920 that his staff develop a set of comparative studies for ships of this type, apparently reflecting his desire to anticipate a possible need for large submarine scouts for transoceanic operations. Type 2 incorporated 474 tons of armor protection but a bureau design report considered it very vulnerable to torpedo attack because it lacked the side protection system in Type 3. The concept was not pursued. This plan provided eight 8-inch guns, diesel machinery, and a surface speed of 15.5 knots in a ship 490 feet long on the waterline, 60 feet in beam, and with a normal surface displacement of 13,500 tons.



S-584-165 "Cruiser Submarine Type 3 -- Protected against Torp. & Gun Fire"

Preliminary design plan for a Cruiser Submarine (Type 3 Protected against Torpedoes and Gunfire). The Chief of the Bureau of Construction and Repair requested in early October 1920 that his staff develop a set of comparative studies for ships of this type, apparently reflecting his desire to anticipate a possible need for large submarine scouts for transoceanic operations. Compared to the other three designs considered, a contemporary Bureau report considered Type 3 superior for having a better balance of capabilities, being deficient only in speed. The concept was not pursued, however. This plan provided four 8-inch guns, diesel machinery, and a surface speed of 11.75 knots in a ship 425 feet long on the waterline, 60 feet in beam, and with a normal surface displacement of 13,500 tons.



S-584-164 "Cruiser Submarine Type 4 (High Speed)"

Incomplete preliminary design plan for a Cruiser Submarine (Type 4 High Speed). The Chief of the Bureau of Construction and Repair requested in early October 1920 that his staff develop a set of comparative studies for ships of this type, apparently reflecting his desire to anticipate a possible need for large submarine scouts. Compared to Type 1, Type 4 sacrificed considerable cruising radius and most gun armament to achieve higher speed, while adding no protection, and accordingly was considered unattractive in a contemporary bureau report. The concept was not pursued. This plan provided two 8-inch guns, diesel machinery, and a surface speed of 18 knots in a ship 550 feet long on the waterline, 42 feet in beam, and with a normal surface displacement of 8,750 tons.

[stevep]

   I think the big problem was that guns, and especially larger guns were a big problem for subs.  By their nature their designed for subtlety and especially as air power becomes better in terms of range and firepower - albeit this was less clear in ~1920 - their going to be increasingly vulnerable.  Even for scouting actions they really need speed and low visibility rather than armour and gun-power because against cruisers or even destroyers they can be vulnerable.  [A few small but fast and maneuverable DDs would be had for any of those designs to hit and if they get close enough to attack with torpedoes themselves the subs are vulnerable.  Any damage which prevents the sub diving basically dooms it unless overwhelming friendly surface power is close at hand.  Also since their quite low in the water with no high points from which to observe their ability to scout is very limited.  If you have seaplanes operating from them that can extend that range considerably but also makes the sub vulnerable when it has to be surfaces and largely stationary while it flies off and then recovers those a/c.

  Britain had an even bigger M class design with single 12" guns for which the best - or least bad possibly - use might have been harrishment of an enemy coastline because if they could get within range of say a port during the night they could surface, lob a few shells in the general direction then submerge and due to their size stay underwater for over a day while moving. - Having said that they had to fully surface to reload the gun, which could be fired from periscope depth and reloading took 75 seconds.

  One of those was lost with all hands and the other two disarmed as a result of the WNT.  One was converted into a minelayer and the other used for testing the idea using a/c from a sub.  In 1932 the a/c version was lost in shallow water after its believed the hanger doors were left open when she dived.  The other was scrapped the same year after testing a minelaying system later used in the Grampus class subs.

  All in all not a really practical idea.

[1bigrich]

The real problem with cruiser submarines is there is no way to have a range-finder of significant height.

Recalling this site from our Useful Links thread over on the BC Board

www.boatsafe.com/calculate-distance-horizon/

if we take a standard heavy cruiser (in this case, a Baltimore class)

pwencycl.kgbudge.com/images/B/a/Baltimore_class__schematic_full.jpg

we have a range-finder at about 112 feet above the water.

Using the formula in the boatsafe site, this puts the horizon for that ship at about 13 miles, or 26,000 yards.

If we have a cruiser submarine with a range finder at 30 feet above the waterline, that puts her horizon at about 6.7 miles, or at about 13,400 yards. That just not enough of a horizon to engage a ship with even inferior armament, not is it enough to take full advantage of the range of submarine's own armament. Even in a shore-bombardment scenario, the shore installation is likely to be able to target the sub before the sub can target installation via its own range finder.

My thoughts,

[lordroel]

Mar 8, 2024 17:49:45 GMT 1bigrich said:

If we have a cruiser submarine with a range finder at 30 feet above the waterline, that puts her horizon at about 6.7 miles, or at about 13,400 yards. That just not enough of a horizon to engage a ship with even inferior armament, not is it enough to take full advantage of the range of submarine's own armament. Even in a shore-bombardment scenario, the shore installation is likely to be able to target the sub before the sub can target installation via its own range finder.

My thoughts,

Radar in later years would solve that problem ore am i talking stupid.

[stevep]

Mar 8, 2024 18:29:31 GMT lordroel said:

Mar 8, 2024 17:49:45 GMT 1bigrich said:

If we have a cruiser submarine with a range finder at 30 feet above the waterline, that puts her horizon at about 6.7 miles, or at about 13,400 yards. That just not enough of a horizon to engage a ship with even inferior armament, not is it enough to take full advantage of the range of submarine's own armament. Even in a shore-bombardment scenario, the shore installation is likely to be able to target the sub before the sub can target installation via its own range finder.

My thoughts,

Radar in later years would solve that problem ore am i talking stupid.

  The radar is still line of sight so it would be limited by the low altitude of the antennas.  Plus not sure how early radar kit would take immersion in water and exposure to waves but I don't think it would fare well.  Unless you have the kit storied inside some waterproof covering but then your got to surface, then remove that before the radar can be used.