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2 Pounder headstamp "MK III GUN ONLY"
- Thread starter Falcon
- Start date
Hi Falcon,
Perhaps an experimental case/ gun development between the Mk II and Mk VIII?
Maybe the Mk III was designed to use the later steel-link belt rather than the original fabric belt? Although I'm not sure what the physical case difference would have been if any?
Interesting enough I also have a "SH&S" 2pdr case dated "/16", but slightly different markings - yours has the "SH&S" in capitals whereas mine is lower case etc
I will post a photo when I can work out why I'm unable to upload any more photos now!~!!
Cheers
Drew
Perhaps an experimental case/ gun development between the Mk II and Mk VIII?
Maybe the Mk III was designed to use the later steel-link belt rather than the original fabric belt? Although I'm not sure what the physical case difference would have been if any?
Interesting enough I also have a "SH&S" 2pdr case dated "/16", but slightly different markings - yours has the "SH&S" in capitals whereas mine is lower case etc
I will post a photo when I can work out why I'm unable to upload any more photos now!~!!
Cheers
Drew
S & S -
Deakins (Silversmiths)
Sidney Works,
Matilda Street,
Sheffield1
'phone: Sheffield 23143
T/a: "Sidney, Sheffield"
One of the previous titles of the company was 'James Deakin & Sons' In about 1936 the company changed its name to 'Sidney Silversmiths' also Sidney was subsequently spelt 'Sydney'
TimG
Deakins (Silversmiths)
Sidney Works,
Matilda Street,
Sheffield1
'phone: Sheffield 23143
T/a: "Sidney, Sheffield"
One of the previous titles of the company was 'James Deakin & Sons' In about 1936 the company changed its name to 'Sidney Silversmiths' also Sidney was subsequently spelt 'Sydney'
TimG
Tony Williams
Well-Known Member
Campbell's excellent book Naval Weapons of WW2 jumps straight from the Mk II to the Mk VIII gun, with no mention of anything in between.
It is rather confusing reading, though, as he also refers to the various mounting Mks.
Yes, this also what I found the other day on wikipedia - jumps from the Mk II to the Mk VIII, stating that the later MK was developed directly from the MK II... in the 1920s, hence why I'm wondering if it was "experimental"?
http://en.wikipedia.org/wiki/QF_2_pounder_naval_gun
I'm wondering if the "Mk III Gun only" was a later stamping?
Cheers
Drew
http://en.wikipedia.org/wiki/QF_2_pounder_naval_gun
I'm wondering if the "Mk III Gun only" was a later stamping?
Cheers
Drew
Hi Falcon,i have found a reference to the MK III gun. It was for naval use and weighed 1.5 CWT. Also not listed as an automatic weapon,so I think for submarine use only,which would tie in with the lightweight mounting. Info date september 1915. Hope this helps,also makes your case a pretty rare one I would say. Tig.
Last edited by a moderator:
Hi Tigbrand,
A very knowledgeable member on this site has kindly sent me a scan of the "Handbook for the 2-Pr Q.F. Gun on Mark III Mounting", dated June 1916, in which this mounting is described as a "High Angle Pedestel Mounting". The Handbook goes on to say "...The base plate is hinged to the superstructure at one side and on the other are provided two hinged screws, the nuts of which are fitted with handles. These screws clamp the base plate when in firing position to two lugs rivited to the superstructure. To house the mounting the screws are slackened one turn and swung into recesses provided in the base plate. The mounting can then be lowered into the well in the superstructure."
Drawings in the handbook show the mount folded down, so it would apear that this gun is for submarines, as you say. It is manually operated (not automatic).
Very little in the handbook re ammunition; all I could see was a small box on one of the diagrams, wherein it gave the following details:-
Charge (Cordite Mk.1) 3ozs 124gns
Projectile 2 lbs
Cubic inches in chamber 10.2
Cubic inches per pound 49.7
Density .558
Total cubic inches in bore 114.4 (I think, can't read it clearly!)
Volumes of expansion 20.45
Muzzle velocity 2000 fs
Muzzle energy 55.5 ft
The barrel was slightly shorter than that of the Mk II gun, but the charge wt given is the same as for the usual ammunition, so still no nearer knowing why is Falcon's case stamped for use with this gun only!
Roger
A very knowledgeable member on this site has kindly sent me a scan of the "Handbook for the 2-Pr Q.F. Gun on Mark III Mounting", dated June 1916, in which this mounting is described as a "High Angle Pedestel Mounting". The Handbook goes on to say "...The base plate is hinged to the superstructure at one side and on the other are provided two hinged screws, the nuts of which are fitted with handles. These screws clamp the base plate when in firing position to two lugs rivited to the superstructure. To house the mounting the screws are slackened one turn and swung into recesses provided in the base plate. The mounting can then be lowered into the well in the superstructure."
Drawings in the handbook show the mount folded down, so it would apear that this gun is for submarines, as you say. It is manually operated (not automatic).
Very little in the handbook re ammunition; all I could see was a small box on one of the diagrams, wherein it gave the following details:-
Charge (Cordite Mk.1) 3ozs 124gns
Projectile 2 lbs
Cubic inches in chamber 10.2
Cubic inches per pound 49.7
Density .558
Total cubic inches in bore 114.4 (I think, can't read it clearly!)
Volumes of expansion 20.45
Muzzle velocity 2000 fs
Muzzle energy 55.5 ft
The barrel was slightly shorter than that of the Mk II gun, but the charge wt given is the same as for the usual ammunition, so still no nearer knowing why is Falcon's case stamped for use with this gun only!
Roger
Hi Roger,interesting information,a copy would be great if possible. We now know what the mk111 weapon was for which is half the battle! The only reason i can think of to distinguish the case is that it either used a different seal at the crimp and primer,or that the primer itself was different, ie,electric. I think the primer is the most likely reason. Thanks for the input,tony.
Tony Williams
Well-Known Member
I doubt that they would switch to electric priming for a "wet" submarine gun, but the ammo may have received extra waterproofing treatment of some kind.
The Handbook states that the gun is fitted with percussion firing.
From reading the Handbook, and seeing the diagram shewing the mount folded down, it would seem that the gun barrel and recoil system must have been dismounted when the submarine submerged. Seems rather involved to have to set the gun up then take it down after any gun action.
Also, isn't this rather a small calibre for a submarine's gun? The (admittedly small) research I have done on the internet seems to indicate that most British subs had 4" guns. I suppose the 2-pdr could have been for anti-aircraft use.
Would the ammo have been kept in a "ready-use" locker close to the gun, or would it have been stored below? If it differed from the "normal" 2-pdr ammo by having better waterproofing, that surely would not have precluded its use in other Mks of gun; rather the other ammo should have been marked "Not for use in Mk.III Guns" if it was not sufficiently waterproof for submarines!
So many questions...
Roger.
From reading the Handbook, and seeing the diagram shewing the mount folded down, it would seem that the gun barrel and recoil system must have been dismounted when the submarine submerged. Seems rather involved to have to set the gun up then take it down after any gun action.
Also, isn't this rather a small calibre for a submarine's gun? The (admittedly small) research I have done on the internet seems to indicate that most British subs had 4" guns. I suppose the 2-pdr could have been for anti-aircraft use.
Would the ammo have been kept in a "ready-use" locker close to the gun, or would it have been stored below? If it differed from the "normal" 2-pdr ammo by having better waterproofing, that surely would not have precluded its use in other Mks of gun; rather the other ammo should have been marked "Not for use in Mk.III Guns" if it was not sufficiently waterproof for submarines!
So many questions...
Roger.
Roger, Tony etc al,
I had not appreciated the interest in the this obscure ordnance and apologise for this belated extract from the 1915 Annual Report of the President of the Ordnance Board on the subject. It is hardly a comprehensive report on the gun but I hope the brief notes give you an idea of the ad-hoc submission by Vickers.
... and then there was the Mark IV!
Tony Williams
Well-Known Member
Thanks for that - any more about the Mk IV?
Norman,
Thanks for posting those 2 pages; the more I find out about these early WW1 guns, the more fascinating it becomes! Line 10 on the 2nd page says "(See 2-pr. incendiary shell.)" - do you have any further information on that projectile, please?
And as Tony says, "Any more about the Mk.IV".
Roger.
Thanks for posting those 2 pages; the more I find out about these early WW1 guns, the more fascinating it becomes! Line 10 on the 2nd page says "(See 2-pr. incendiary shell.)" - do you have any further information on that projectile, please?
And as Tony says, "Any more about the Mk.IV".
Roger.
Tony & Roger,
The early small calibre guns are fascinating, I agree, and the PRO has a great deal of information on them in its collections of Ordnance Board minutes; the 1-Prs, 1 1/2-prs, 2-Prs and obscure 2 1/2-prs all feature (even the 1 1/4-pr might get a mention).
Re the Mk IV gun I will have to dig out some notes made many years ago when I thought I could remember everything forever which will why they will lack much in the way of substance.
The Mk IV was provided to meet an RNAS anti-submarine requirement and initially intended to be mounted on seaplanes but then tested on 'airships' (I might have the nomenclature wrong for these things). The Mk V and VI guns I think were both destined to be tank guns and certainly the Mk VI nearly made production but was stopped by the D of A in 1918.
I will see what I can find.
Ditto on the ammunition. As you will know only too well the experimentation on ammunition during WW1 was considerable but it would not be unusual to find that a design of say, a 2-pr incendiary, was broadly similar to another calibre (eg 1.59). I am hoping to get to the PRO on Saturday so if I get the chance I will see what I can tease out but dont expect anything diagrammatic.
Tony Williams
Well-Known Member
The Mk V fired a long 40x240R cartridge(see below). I had it down as for an aircraft gun, but it could have been for tanks - or dual purpose.
1 PR Maxim HE (37x94R), Vickers 1 PR Mk III HE (37x69R), Vickers-Crayford 1.59" AP (40x79R), 1 PR COW gun HE (37x190), Vickers 1 PDR HE(37x123R), Vickers 2 PR No.1 SAP (40x158R), Vickers 2 PR Mk V HE (40x240R). Note that the 1 PR Mk III and the 2 PR Mk V shells are both fitted with the sensitive No.131 fuze, intended to detonate on impact with fabric.
Had a quick rea of Janes WWI section on British submarines; lots of classes had 3in AA presumabley 3in 20cwt. D class had 12pr. F class were designed to take a 2pr pom pom but no guns were fitted. is there a clue here? but like all 'good' books on ships they dont seem to get the gun bits very precise.