US naval 5 inch DP guns - any good?

These 36 cal. guns in their characteristic dual turrets trademarked US Navy ships in WWII, appearing on everything from (later) destroyers to carriers and battleships. My question is - were they any good against A/C? I can't recall any reference to their shooting a plane down. Always thumbs up on the 40mm guns, but silence on the 5 inch even after proximity fuses became available. Were they just making smoke? Has anyone heard anything at all positive?

The USN's 5' guns were quite good, and as the 'd/p' appellation suggests, capable of both air-defense and bombardment of either surface ships or ground targets.

The 5' in air-defense i.e., used with the proximity fuse) had about the same range as the US Army's 90mm AAA gun, but had a substantially larger bursting charge and a larger shrapnel casing, which gave it a larger radius of lethality. Mounted on destroyers as well as on larger ships such as a/c carriers, they did good work with VT fused rounds in conjunction with USN's 50mm AA ranging radars. But since they could and did engage targets much farther from the defending ships than could the 40mms, film coverage of their successes is lacking.

A version of it (with truncated barrel) was fitted to many late-war US submarines, and was used thereby against transports and freighters and very occasionally against small patrol craft.

Its range and accuracy were also first rate in the surface-ship bombardment role.

D.K. Brown's comments on the 5'/38 are instructive ('Nelson to Vanguard', Chatham Press) - it was clearly and simply the best heavy DP gun of the war. Unfortunately the Admiraly fissled and fuddled about with various permutations of 4' AA, 4.7' heavy DP, 5.25' DP and 4.5' DP before coming up with something as good or better than the American gun in the upper deck (UD) 4.5' mount, but that only made it onto one or two Battle-class destroyers before the end of WW2. NO other navy had anything to touch the 5'/38 (or its fire-control, RN high-angle directors being poor and all other navies worse).

It seems to have been a bloody good gun.

They were 38 calibre, not 36. They were considered the best DP guns of all, especially once the proximity shells were made available.

The 40mm, while deadly, proved too light to stop a kamikazi, which led to development of the 3' 50 cal. automatic, which is a whole 'nother story.

My uncle, Buddy Hacker, was on the escort carrier Mankin Island off Iwo Jima, and he told me he saw a Japanese plane diving and a 5 inch fire, and hit it rigth on the nose. The plane just vanished in a blaze of orange. I have no doubt the 5 inch 38s were very effective. You will note, by the end of the war the U.S. decided to replace the 40mm with 3 inch guns. Yes, the twin 40mms mounts were replaced with single 3 inchers, and the quad mounts with twin 3 inch. I have seen pictures of St. Paul class crusers so modified. Between radar control and proximity fuses, the larger cannon mounts were much more effective than 40mms as no 40 at that time had a proximity fuse, all were timed fuses.

My uncle, Buddy Hacker, was on the escort carrier Mankin Island off Iwo Jima, and he told me he saw a Japanese plane diving and a 5 inch fire, and hit it rigth on the nose. The plane just vanished in a blaze of orange. I have no doubt the 5 inch 38s were very effective. You will note, by the end of the war the U.S. decided to replace the 40mm with 3 inch guns. Yes, the twin 40mms mounts were replaced with single 3 inchers, and the quad mounts with twin 3 inch. I have seen pictures of St. Paul class crusers so modified. Between radar control and proximity fuses, the larger cannon mounts were much more effective than 40mms as no 40 at that time had a proximity fuse, all were timed fuses.

My uncle, Buddy Hacker, was on the escort carrier Mankin Island off Iwo Jima, and he told me he saw a Japanese plane diving and a 5 inch fire, and hit it rigth on the nose. The plane just vanished in a blaze of orange. I have no doubt the 5 inch 38s were very effective. You will note, by the end of the war the U.S. decided to replace the 40mm with 3 inch guns. Yes, the twin 40mms mounts were replaced with single 3 inchers, and the quad mounts with twin 3 inch. I have seen pictures of St. Paul class crusers so modified. Between radar control and proximity fuses, the larger cannon mounts were much more effective than 40mms as no 40 at that time had a proximity fuse, all were timed fuses.

38-caliber, not 36. They appeared on all US destroyers later than the four-pipers, although on a handful of destroyers they could not be fired at a high angle.

My question is - were they any good against

Very.

I can't recall any reference to their shooting a plane down.

If you read Morison' account of the Battle of Santa Cruz, one US battleship wound up separated from the rest of the carrier group, and was attacked repeatedly by Japanese planes, and shot down quite a few. One US pilot flew within several miles and was promptly shot down by mistake.

The 5' were excellent heavy AA guns, and the 40mm were excellent light AA guns (although only marginally useful against kamikazes). The 1.1' that the 40mm replaced were pretty bad, and the 20mm were just too light to be really useful.

If you've heard anything positive about USN AA fire before Santa Cruz, it was doubtless because of the 5', since the 40mm wasn't available before then.

Yes. In addition the 40mm had a a short range for naval use. The 20mm Oerlikon was found nearly useless in actually stopping enemy attacks, it was more a 'retaliatory' weapon, and even though the 40mm was better its usefulness still suffered from its limited range.

Tero P. Mustalahti

My understanding is the 20mm was discouraging for enemy dive bombers, though unfortunately it generally couldn't really chew up a plane until it was already close enough to release its ordnance, rather defeating the purpose. Better late than never I suppose.

I believe at Eastern Solomons, for example, many of the Japanese planes dropped by shipboard AA fire were dropped by 20mm. Five inch guns needed efficient radar fire control for real effectiveness, and that system wasn't reliable that early in the war.

Pete Hughes pustulated:

Some evidence as to the value of the 5'/38 (and equally important, the MK37 FCS, without which the gun would simply be another naval gun)...

The MK37 was the most durable, maintainable and effective of cntemporary DP FCS, in essence one of the world's earliest successful 'computers'.

The 5'/38's still in service today in some small navies employing 'leftovers', old GEARINGs or SUMNERs and auxilliaries equipped with the gun. Guns which stick around for more than 60 years must have something in their favor.