Post War British Naval cases

[Vasco Da Gama]

For interest attached are a couple of photos of 3 British post WW2 Royal Navy cases. These are 6in N5 152x1180 marked 6in Mk N5 Gun, RLB 1959 Lot 39. In paint N2 RNP 253 34lb 8oz. I understand that this gun armed the Tiger class cruisers. Next in calibre is a brass 4.5in Mk 3 to 5 115x640, this replaced the wartime Mk1 115x695, marked 4.5in Mk 3-5, lot 122, 1975 N5. In paint Mk N 9 12lb 10ozs RNB TRE 11/76. Last, in the middle, is a steel 3in L70 again from the Tiger class cruisers 76.2x662, marked 3inch Mk N1 Gun Lot 378, EOC 1965 and in very small type 21.7.65. Comments welcome!

 

[Tony Williams]

Nice trio!

I've had some difficulty pinning down the 4.5 inch variations, from the original fixed ammo at the start of WW2, through to the separated ammo during WW2 and into the 1960s, followed by the fixed ammo for the Mk 8 gun.

If the 114x695R is for the Mk 1 gun, I presume this was the fixed ammo?

The 114x640R Mk 3-5 would therefore have been for separated ammo (and the postwar Mk 6 used the same, I presume).

I understand that the current Mk 8 uses a 114x700R case - is this correct?

Confirmation or corrections welcomed!

 

[Vasco Da Gama]

Evening Tony, I currently have 2 115x695 cases dated 1940 and 1944 both marked with the N for naval use and both bearing the crimping marks for fixed rounds. I believe that these cases marked 4.5in Gun, without any further Mk numbers are for the Mk1 naval weapon. I have also had the same case without the N marking dated 1940, this I think was used in the army manned anti-aircraft Mk2 gun. This follows the description in Hogg's history of British WW2 artillery, which suggests that both the Mk1 and Mk2 used the same ammunition. I also have a training round for the Mk8 gun which was used in trials to cure issues with the auto- loading system. It has black and white tape on the case to help with high speed photography of the handling process. This round is definitely fixed and 115x700.

 

[radioman1]

Hello All
1 As you say the 6" and 3" cases are from the Lion Tiger and Blake class ( Should have been filled at ROF Glascoed )

2 The 4.5 case was filled at RNAD Trecwn ( The charge would have had a N39 primer fitted)

3 We also filled Mk 11 (This charge used a N43 primer )

5 Was told that some ships did not use the same voltage for the gun fitted

Hope this info helps

Steve Ex RNAD Trecwn

Ps may have been one off the cases that i filled

 

[charley777]

Well, comments invited so I will be pedantic........British naval 4.5 inch guns are actually 4.45 inch........therefore correct metric designation is 113x640R, 113x698R, 113x700R. And Tony W seems to have summed up the sequence of cases nicely....yes 700mm is the length for the Mk 8 autoloaders.

 

[Tony Williams]

That raises the interesting question as to whether cartridge designations should be actual or nominal.

The RN has always referred to this as the "4.5 inch" gun, and this has always been translated into metric as 114mm. It is described as 114mm in Jane's Ammunition Handbook and in Friedman's World Naval Weapon Systems. Nobody has ever called it 113mm. So I'll stick with 4.5 inch and 114mm. If the makers call it that, and the users call it that, then that's its official designation.

There are other examples of such nominal calibres, right down to current developments - the ATK/GD-OTS "Super 40" ammunition is still officially described as 40x180 even though during development the actual calibre was reduced to 39mm. It is of course right to point out in any description that the actual calibre is 39mm, but that doesn't stop the official designation being 40x180.

 

[Tony Williams]

Some data on the 4.5 inch guns and ammo from Campbell's classic Naval Weapons of World War Two, plus other sources:

The guns were given separate Mark numbers from their mountings, which complicates matters. The guns first:

Mk 1: breech design very similar to 4.7 inch Mk XII but with ignition modified to electric by omitting the percussion elements.

Mk II: army AA weapon, generally similar to navy guns.

Mk III: interchangeable with Mk I, differed only in that it was designed for electric firing only.

Mk IV: modified to suit use in converted 4.7 inch Mk XII mountings (destroyer single mountings).

Mk V: postwar gun introduced in 1947, although much development during the war. Different breech design with faster loading cycle, designed for separated ammunition. The standard gun until the automatic Mk 8 came along.

Mountings (main types only - there were variations):

Mk II BD (between decks - slightly recessed installation) HA mounting with two Mk I or Mk III guns, used in various aircraft carriers and modernised capital ships. Fixed ammo used (114 x 696R)

Mk III UD (upper deck) - HA mounting with two Mk I or Mk III guns, used in various ships. Fixed ammo used (114 x 696R).

Mk IV - HA mounting with two Mk III guns, in Battle class destroyers (separated ammo, 114 x 644R)

Mk V - LA destroyer mounting with single Mk IV gun (separated ammo, 114 x 644R)

Mk VI - postwar HA mounting with two Mk V guns (later both gun and mounting were redesigned Mk 6); the "rounded cube" turret as fitted in 1960s destroyers and frigates. (separated ammo, 114 x 644R)

Mk 8 - 1970s automatic gun/mounting, 114 x 700R fixed ammo.

So apart from the postwar Mk 6 and Mk 8, whether or not the ammo was fixed or separated depended on the mounting, not the gun - no doubt the cause of some confusion!

 

[radioman1]

Hi Tony

1 The smallest imperial gun size was 3"

2 Below that we used metric eg 40/60mm, 30 mm ,20 mm.

3 The charge weights used were in Lbs and ozs.

Hope this info helps

 

[steve rb]

Lovely to see some other 6" cases. I have a couple that come with a story - they were actually from the HMS Tiger herself when in Gibralter, and were the subject of a bet between a couple of RAF Buccaneer pilots and the duty officer on the Tiger in February 1973 (as ever I guess, apparently a plan devised in the bar the evening before....). It involved the frustration of the battle cruisers officer to have a huge 'splash target' used for training purposes for the fighter jets on board as it took up so much space. The RAF guys bet they could sink it (it was not supposed to be shot at, only to provide a large ship sized plume of water to shoot), the deal in return was a couple of 6" Mk5N cartridges to keep. Story goes that they did indeed bang seven shades out of this thing but didn't sink it - however it was so badly damaged it needed to be scuttled anyway! And the two cartridges were delivered to the pilots by helicopter as the cruiser departed. I am now the proud owner of these beauts.

 

[Quatermass]

Some data on the 4.5 inch guns and ammo from Campbell's classic Naval Weapons of World War Two, plus other sources:

The guns were given separate Mark numbers from their mountings, which complicates matters. The guns first:

Mk 1: breech design very similar to 4.7 inch Mk XII but with ignition modified to electric by omitting the percussion elements.

Mk II: army AA weapon, generally similar to navy guns.

Mk III: interchangeable with Mk I, differed only in that it was designed for electric firing only.

Mk IV: modified to suit use in converted 4.7 inch Mk XII mountings (destroyer single mountings).

Mk V: postwar gun introduced in 1947, although much development during the war. Different breech design with faster loading cycle, designed for separated ammunition. The standard gun until the automatic Mk 8 came along.

Mountings (main types only - there were variations):

Mk II BD (between decks - slightly recessed installation) HA mounting with two Mk I or Mk III guns, used in various aircraft carriers and modernised capital ships. Fixed ammo used (114 x 696R)

Mk III UD (upper deck) - HA mounting with two Mk I or Mk III guns, used in various ships. Fixed ammo used (114 x 696R).

Mk IV - HA mounting with two Mk III guns, in Battle class destroyers (separated ammo, 114 x 644R)

Mk V - LA destroyer mounting with single Mk IV gun (separated ammo, 114 x 644R)

Mk VI - postwar HA mounting with two Mk V guns (later both gun and mounting were redesigned Mk 6); the "rounded cube" turret as fitted in 1960s destroyers and frigates. (separated ammo, 114 x 644R)

Mk 8 - 1970s automatic gun/mounting, 114 x 700R fixed ammo.

So apart from the postwar Mk 6 and Mk 8, whether or not the ammo was fixed or separated depended on the mounting, not the gun - no doubt the cause of some confusion!

And don't forget the 4.5in 8cwt QF Mk I, a very different gun but still 4.5 inch and post war.

 

[charley777]

Thanks for sharing your thoughts, Tony W, on metric designations. A question that has exercised me for a while. What you say makes sense, though various inconsistencies come to mind. For example, Germany described some of its 105mm guns as 10,5cm, wheras others were known as 10cm. However i feel disinclined to list the latter examples as 100mm cases. And we do round things out a bit, eg 76.2mm versus 76mm. Or 87.6mm versus 88mm. Which does raise another interesting example.......should my various sizes of Austro-Hungarian 8cm case be listed as 80mm or the actual 76.5mm. The Super Forty situation is also interesting....thanks, i didn't realise that their bore is now 39mm. To me, this is one of the interesting aspects of studying/collecting ammunition.......all the inconsistencies and different methods of measurement (Imperial, metric, Pounders, etc).............always more to learn.

 

[Tony Williams]

Charley, you are right that the situation is confusing, and I certainly don't know the answers.

A further complication is with ammo which has stub cases of larger diameter than the calibre. Do you describe the cases by the actual inside measurement, which may be considerably bigger than the projectile calibre? For example, the German WW2 8cm PAW 600 hi/lo pressure gun is of 80mm projectile calibre but the inside diameter of the case mouth is 105mm. And there are the German squeezebores like the 28/20 s PzB 41, which has a 28mm case mouth but a 20mm muzzle diameter...

 

[charley777]

Yes, exactly................and the description of Blank cases too. Personally, to have consistency within my own database, I tend to use the starting caliber as the main listing....so that, e.g., a Swedish Blank case (at 245mm) for a 40x364R gun and a German Blank (at 350mm) for the same equipment are described as 40x245R and 40x350R respectively. If one used actual case mouth measurements it would surely complicate things unnecessarily. Similarly, with separate loading cases, the mouth may be quite considerably larger than the actual bore, so I use bore size. Don't want to get too anal about it........I guess it is more about communication and having a shared understanding of which particular case one means. It is something like the question of "correct" pronunciation of e.g. botanical Latin..........many systems are used globally........it doesn't matter how it's pronounced as long as the plant in discussion is clearly recognized by anyone from anywhere. So I use 81x155R to describe the 8cm PAW case (with further notes to explain the use of lFH cases).............and so on and so forth (-: Thanks Tony