RN going with 15' or 16' for KGV BB - pros cons?

[tomo pauk]

The Royal Navy went, for several reasons, for 14 in guns for their King George V battle ships. What would be the benefits, apart from obvious (better range shell power, going with more or less modified existing guns)? What would be the drawbacks? How many bigger guns would be the ship of that size able to carry, without compromising the other important 'ingredients' (protection, speed etc) of the class?

MODERATORS: this is definitely a wrong subforum for this topic, please remove it to the ww2 one

 

[vinnye]

The RN may have been better advised going for 9 x 15 inch guns in 3 triple mounts. The quad guns on all of the KGV class ships caused problems in service. In some cases half of the available guns were not in service due to mechanical / safety issues!
Not really what you want when facing up to the Bismark!
The 16 inch gun route was considered but stability was thought to be an issue with the B gun osition during a broadside.
This may not actually have transpired to be the issue envised as the US navy used triples to good effect!

 

[Shortround6]

The British could design a ship that wouldn't flip firing 9 guns broadside. They had already done so with Nelson and Rodney. Their main armament rotating weight (not the barbettes and stationary equipment) were about 400 tons (10%) heavier than the main armament rotating weight of the KGVs. Without giving up something else (protection or propulsion) such a ship would have come out somewhat heavier and exceeded treaty limits. It is not JUST the weight of the armament but the bigger hull to float it and more armor to protect the bigger hull and so on.
Most "35,000" ton battleships exceeded the 35,000 tons, some by about 1600-1800 tons and some by 7,000 tons and that is at the "Washington" displacement (no fuel, little feed water, and limited ammunition).

British had no modern 15in gun in the works and it takes as long or longer to design and build the guns and mountings as it does the rest of the ship, a reason the British canceled the Lion class ( 9 X 16 In in triple turrets) and built the Vanguard (8 X 15 in in twin turrets) using left over guns and mountings from WW I ships. Four turrets means a longer hull than three turrets.

Any new large size gun mounting has problems and the level of experience needed is not helped by small numbers of mountings. Many British sailors had experience with the 15in dual over quite a few years, A lot fewer had experience in Nelson and Rodney despite 12 years of service. Experience with the 14 in mountings was non-existent in 1940.

During WW I somebody claimed that a dreadnought gun mounting was the most sophisticated piece of engineering in the world. A power driven moving mass of 800 tons or more (WW I, WW II mounts could go 1400 tons easy with the 18in mounts of the Yamoto going around 2500tons) with elevating guns of 80 tons or more, controllable to a fine degree and fitted with shell and propelling charge elevators, power rammers, ventilation systems and communications systems.

For long range gunnery you need a certain minimum number of guns too. 4 guns was generally considered the minimum salvo for accurate ranging, With a time of flight of to longer ranges taking longer than the time needed to load the guns many navies liked to use 1/2 salvos, spitting the guns or turrets in 1/2 (or 4/5 for 9 gun ships) to speed up the initial salvos and get on target quicker. Anything less than 8 guns was not considered a good "investment" Repulse and Renown being leftovers of Jackie Fisher.

 

[davebender]

RN triple turrets on Nelson class battleships had problems. RN quad turrets on KGV class battleships were little short of a design disaster. Why not stick with the reliable twin turret armed with proven 15" main guns?

Mk II twin turret.
Same as HMS Hood. This model turret had various improvements over Mk I turret fitted to QE class battleships.

15"/45 naval rifle.
Updated version of the tried and true WWI era weapon.

 

[VBF-13]

From a ballistics standpoint the bigger the gun the more alteration in the ballistics of the projectiles in each successive firing of the gun. That's due, in part, to the immense heat developed by the rapid firing as well as to the wear and tear and chemical deposits left in the bore as the projectiles go through. In short, the bigger the guns, the more maintenance required, and the more trips to port to have the guns overhauled. In fact, at times, the guns were even taken out of the turrets, and replaced with others with fresh linings. I know the USN held extra guns in readiness, for just that purpose. I'd imagine the RN did, too. But, that'd be another consideration, I'd think.

 

[davebender]

bigger the gun the more alteration in the ballistics of the projectiles in each successive firing of the gun.

How many dreadnoughts fired enough main gun rounds to wear out the barrel? I suspect not many.

Army artillery and AA guns are an entirely different matter. It was common for those type weapons to fire thousands of rounds during a year of combat.

 

[norab]

How many dreadnoughts fired enough main gun rounds to wear out the barrel? I suspect not many.

Army artillery and AA guns are an entirely different matter. It was common for those type weapons to fire thousands of rounds during a year of combat.

perhaps more than you would think. Here are the numbers for the The USN big guns
"Barrel life—the approximate number of rounds a gun could fire before needing to be relined or replaced—was 395 shells when using AP, increasing to 2,860 for practice rounds. By comparison, the 12"/50 caliber Mark 8 gun of the Alaska large cruisers had a barrel life of 344 shots, while the 16"/50 caliber Mark 7 gun fitted in the Iowa-class battleships had a barrel life of 290 rounds"

 

[pinsog]

perhaps more than you would think. Here are the numbers for the The USN big guns
"Barrel life—the approximate number of rounds a gun could fire before needing to be relined or replaced—was 395 shells when using AP, increasing to 2,860 for practice rounds. By comparison, the 12"/50 caliber Mark 8 gun of the Alaska large cruisers had a barrel life of 344 shots, while the 16"/50 caliber Mark 7 gun fitted in the Iowa-class battleships had a barrel life of 290 rounds"

How many 16 inch rounds did an Iowa class battleship carry on board?

 

[norab]

As configured for WWII and Korea, just over 1200 16" projectiles

 

[Shortround6]

Powders changed over the years, Some WW I battleships had barrel lives of under 300 rounds, in some case close to 200 rounds. With magazine capacities of around 100-120 rpg that doesn't give a lot of leeway for gunnery practice. General practice was to re-gun (or reline) at about 1/2 the "expected" barrel life. Going into battle with a 1/2 worn and knowing that it will exceed it's expected life before the magazines are empty is not good. More modern powders helped. Lower velocity/lighter charges for HE shore bombardment rounds helped an awful lot.

If a battleship didn't wear out it's guns in 8-10 years of peacetime duty it probably wasn't getting enough practice/training to do it's job in war time.

Campbell's lists 335 EFC (effective full charge) as the life of the 15in gun.

The 15in British was 42 calibers in length. There was no 45 cal length gun.

New mountings for the old gun/design probable would have had the same problems as the 16 in or 14 in mounts. The guns themselves were not the real problems but the shell and powder hoists and safety interlocks.

 

[VBF-13]

For what it's worth, Navy Yard in Bremerton WA, battleship with worn out gun linings being refitted with new 14" guns (credits: Battle Stations, Wise Co., NY, 1946)...

 

[davebender]

Britain 15/45 (38.1 cm) Mark II
15"/45 was planned for the KGV class. So I've got to assume that's what they would get if the RN opts for 15" main guns.

 

[krieghund]

Germany was pretty much in the same boat. They improved the WWI pattern with the 15"/47cal but the Bismarck was merely an improved Bayern design but the citadel was still too high above the waterline and the deck armor was not as thick or as well protected as her contemporaries. Of course by WWII the battleship was past its day with the advent of air power.

Of course there is still to be something with a battleship at hand....just kicked the aliens ass off of Hawaii!!!

 

[Tante Ju]

Bismarck class had nothing to do with the Bayern...

 

[krieghund]

Bismarck class had nothing to do with the Bayern...

Did you mean that the other way round? anyway my source for my comment is from "Battleships and Battle Cruisers, 1905-1970: Historical Development of the Capital Ship" by Siegfried Breyer

 

[fastmongrel]

RN triple turrets on Nelson class battleships had problems. RN quad turrets on KGV class battleships were little short of a design disaster. Why not stick with the reliable twin turret armed with proven 15" main guns?

The triple 16" mounts did have problems for the first ten years of service shortage of money prolonged the fault busting but had the bugs worked out by 1939 and they proved reliable but didnt quite live up to the original designs with regard to rate of fire due to the loading cycle not allowing single tube reloads.

The 14" mounts were initially unreliable basically because they were a brand new design rushed into service. HMS Prince of Wales went into battle without a proper work up because an air raid had damaged her at the dockyard during fitting out and before the Battle of Denmark Strait she had carried out one partially succesful practice shoot and had a notably green crew. Bismark had carried out approx 6 months of shoots by the time she went to the bottom, if POW had not been damaged she would have had the same work up and she might have done more than just sign Bismarks death warrant. In 1943 against Scharnhorst HMS Duke of York showed good reliability considering she was pounding into a force 11 gale with every boiler lit and the ship pitching 40 foot. By 1945 the mounts were reliable with HMS Howe showing excellent reliability during shore bombardment missions off Okinawa. The 14" guns were always reliable it was the interlocks and shot hoists proving troublesome, accuracy was reckoned to be exceptionally good.

The 15"/42 was probably the best all round heavy gun and mount combination ever to go to sea but by 1939 it was past its best. With hindsight we can see that a KGV built with the 15/42 would have been better in 1941 but expecting the RN to fit Grannies teeth to a new battlewagon isnt going to happen it would be like fitting Vickers .303s to a Spitfire.

 

[mike siggins]

i read somwhere the italy had one of the best heavy ship gun of the war

 

[mike siggins]

not that they got used to there full potential

 

[davebender]

By 1945 USN torpedoes were reliable too. That doesn't help during 1941 when weapon reliability was a matter of life or death for British and American military personnel.

 

[fastmongrel]

By 1945 USN torpedoes were reliable too. That doesn't help during 1941 when weapon reliability was a matter of life or death for British and American military personnel.

The 14" mounts were reliable earlier than 1945 you have selectively quoted. In 1941 POW managed to fire 96 of a possible 132 rounds, Bismark fired 93 out of a possible 104 or 112 depending on source. With no gunnery records from Bismark surviving no one can be sure.

KGV which had had a longer (though still too short) work up had problems but only iirc after firing half broadsides without problem for 47 minutes.

In 43 DOY managed an 80% firing rate in conditions that meant 1540 pound shells were jumping out of the hoists. We dont know what Scharnhorst managed in the same conditions but from RN records she certainly wasnt firing at a higher rate per tube.

In 45 Howe fired at shore targets so it is not comparable to the earlier actions but she managed to better the rate of any US vessel firing at the same time. This of course means nothing as all complex machines have good and bad days on another day a US vessel might have bettered Howe for % of succesful firings.

In 3 ship v ship actions the KGV class 14" mounts were 2 for 0 not bad for a design disaster.