How did they waterproof naval guns on subs?

[Frank46]

I've been wondering for quite sometime about the naval guns on subs. In the movies you always see them pulling the plug from the muzzle and start firing. So were these guns specially made to have the firing mechanism's waterproof or was there a lot of inspections and maintence involved?. Frank

[seaboltm]

I think that was some type of muzzle protector. I would think it is virtually impossible to completely waterproof a deck gun. I think you had a lot of maintenance. This is one reason the military has sought out rust proof coatings for weapons.

[Stephen Cohen]

I guess the plug was to stop fish setting up home LOL. I too often wondered how they survived all that water.

[BruceB]

If NVCurmudgeon sees this thread, maybe he'll chime in.

I know he served in US diesel subs 'back when'; whether or not they still had deck guns I don't know. I believe the gun muzzles had a screw-in plug of some type, but there's a heck of a lot of other stuff that needed protection as well.

[gray wolf]

Lots of Hoppes #9

[Artful]

http://pigboats.com/subs/deckguns/deckguns.html

http://www.fleetsubmarine.com/guns.html


5"/25:
This was the first American submarine deck gun designed specifically for submarines, and proved the most effective because of this. The short barrel improved accuracy on a submarine's rolling deck, and the five-inch round was powerful enough to cause serious damage to a target.

In addition, because the gun was designed for submarine use, it was built from rust-resistant steel, and with pressure-tight fittings, to reduce maintenance. The traditional pedestal mount was eliminated, with a dual-purpose mount employed, which was both quicker training, and could elevate the barrel to 45°, making it potentially much more effective in an anti-aircraft role. (It was not, however, used in that role and no suitable ammunition was ever issued.)

Late in the war, several boats were fitted with a pair of 5"/25s, as well as a simple director system, allowing coordinated fire.
http://www.fleetsubmarine.com/graphics/5-25-front.jpg
http://www.fleetsubmarine.com/5_25_gun.html

[Artful]

http://www.dsto.defence.gov.au/publications/3442/DSTO-TR-1622.pdf


2.7 Albacore
Following the end of World War II both the British and United States Navies acquired
some Type 21s for evaluation. They were amazed at the advances in the German boat. The
United States then played "catch-up" and the Bureau of Ships adapted the extremely
successful American fleet submarine of World War II for greater underwater speed by
streamlining the hull and conning tower, removing all appendages - including the guns -
and dramatically increasing the battery power. The submerged speed increased from 8.75
knots to 18.2 knots [3].

They went even further in copying the German approach. In 1948, the Committee on
Undersea Warfare of the National Research Council initiated an effort to accumulate the
collective wisdom of the naval and scientific communities on the hydrodynamics of
submerged bodies. Out of this evolved the design of Albacore with a shape giving the
minimum underwater resistance based on the best available hydrodynamic research.

A larger single screw, slower revving propeller provided the best propulsive efficiency.
The control arrangements were varied in a number of modifications to give the shortest
turning circle. Most importantly, the sonar was later placed in the streamlined nose for
maximum effect [3]. Snaproll was reduced by trialling an adjustable trailing edge flap on
the fin. The fin was made as small as possible in order to reduce drag (a streamlined fin
represents about 25% of the total drag). The length-to-draft ratio of Albacore was 7.723,
which compares to Collins at 9.96.

A paper describing the design was presented by Captain Jackson at Warship í96 [4]. A
chapter in the SNAME publication [3] on American submarine development is equally
illuminating. Albacore on batteries reached a submerged speed of 33 knots and a surface
speed of 25 knots. Its radical diesel engines with a vertical crankshaft produced more
power per unit weight than before, but were unreliable. The vertical arrangement required
less critical longitudinal space and they developed 15,000 SHP. The large single screw
showed a remarkable propulsive efficiency of 0.9
http://i2.wp.com/www.defensemedianetwork.com/wp-content/uploads/2013/10/USS-Albacore1.jpg
Figure 6. Albacore being tested in a wind tunnel

[Alan in Vermont]

FWIW, The Albacore is now sitting in Portsmouth, NH, as a museum http://www.ussalbacore.org/html/visitor_center.html

My family went there a while back, IMO it's much nicer than some of the warship museums I have been to.

[Trey45]

My memory may not be accurate here, but I seem to recall hearing that the deck guns on Jap subs of WW2 era had their firing mechanism removed for diving and reinstalled when they ran on the surface.

[Mk42gunner]

The muzzle plug is called a tompion. Other than that I don't know for sure; but I bet there was a lot of heavy grease involved somehow.

Back in the early 1990's one of the civilian Armorers that I worked with told me he was one of the last Gunner's Mates on subs, sometime in the early 1950's. I don't know if they still had deck guns then; but he never said anything about taking any special precautions.

Robert

[Frank46]

Thanks for all your answers. I was wondering about the deck guns when the article about the Japanese sub that was recently discovered. Google did come up with some answers but then again maintence was probably the keey to insure that these guns aka naval rifles or cannon went bang when they were supposed to. Thanks again,Frank

[NVcurmudgeon]

Back in the "olden days" (post Korea, pre Viet Nam) there were precious few submarine deck guns. WWII boats were being converted in accordance to the greater underwater propulsion program, or G. U. P. P. (pronounced Guppy) modification program. The guns were removed, conning towers and most bows streamlined, snorkels added, batteries improved, etc. The idea was to make the submarines more effective as submarines. There were a very few left with guns for cooperation with Hollywood, and rumor had it, "gumshoe" operations. I just always assumed that the guns were made of corrosion resistant steel. At the time, mid 1950's, the biggest gun aboard most submarines was the 1928A1 Thompson submachine gun. Lots of fun to shoot at floating kelp!

[popper]

Lots of lead based paint. Deck guns were used for surface attacks, not defense. Although the 5" was developed for aerial defense to replace the ineffective 3" & 40mm, it would be impossible on a sub. A/C 30 & 50's were used. All naval guns are/were made from corrosion resistant steel. As a side note, Mk68 FLIR proto failed due to SW corrosion of conformal coated electronics. I got to scrub down blast door seals daily and relube with silicon grease. You just can't stop SW corrosion.