Landships II

higgins · Corporal

Mark IV AP/HE/Canister question

Lothianman · Colonel

I too would be very interested to know. I'm trying to make sense of an odd report of a 6pdr accident in a Mark IV (don't want to go into details about it just now as I need to finish looking up the sources and don't want to publish stuff I'm not 100% sure about) and this is highly relevant.

I also wonder, did they use clearing charges/short rounds? The kind which was used to clean out obstructions in the barrel, with a reduced propulsive charge and perhaps some copper foil to clean out the bore? This would seem to be relevant for the occasions when the guns got mud up their muzzles. However I have no idea if the Hotchkiss QF 6pdr had such rounds ...

Gwyn Evans · Legend

My local artillery expert says that the Hotchkiss Nordenfeldt QF 6 pdr probably had clearing rounds but he's never seen one. He thought it highly unlikely that AP would be used because it wasn't needed, as armour plate was relatively thin. I asked whether it would be any use against fortifications but he thought it would still need a heavy HE charge, and added that the 6 pdr didn't really have the muzzle velocity for serious armour piercing.

Gwyn

higgins · Corporal

Thanks Gwyn,

That's helpful. A confusing subject to say the least.

David Fletcher mentioned to me that solid shot, a common shell AP/HE, and canister were used on the Mark IV (I'd figure in low percentages for anything other than the AP/HE). As the German A7V's 57mm cannon�used a "panzerkopf" AP (modified HE shell with a hard tip), APHE, and canister, I was figuring the Mark IV had something similar (being a 6pdr as well). Also, nothing I've seen (Hogg, etc)�shows what 57mm/6pdr canister/case rounds looked like, or how many lead/steel balls they carried. Shrapnel rounds didn't seem to be used for either gun.

Thanks for the help- and thank your resident artillery expert for me.

Dave

Pzkpfw-e · Commander in Chief

Weren't these basically naval guns, so whatever the navy used, the armoured corps would too?

Rectalgia · Legend

I thought the Navy intended them mostly for use against wooden-hulled motor torpedo boats Adam, with a blackpowder bursting charge which is very effective against wooden craft (lots of large splinters, doesn't snuff out flame to the same extent as HE). I could be completely wrong, that may have been superseded before WW1 had progressed very far.

Steve

CharlieC · Legend

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The Mark IV tank 6 Pounder was made by Vickers, it was similar although somewhat heavier than the Hotchkiss 6 Pounder. These guns (and the Nordenfeldt 6 Pdr) were originally designed as anti-torpedo boat guns - rapid fire guns with an effective range of about 1000 yards. The torpedo boats of the time were quite small, iron hulled, low freeboard boats powered by a steam plant often derived from railway locomotives.�

The point of these guns was their ability to engage fast moving targets at close range which the main armament of naval ships was mostly incapable of doing. The 6 Pounders were the last of an evolutionary arms race between torpedo boats and the guns starting off with the Nordenfeldt machine guns (25mm) through 1 Pdr (37mm) guns to 3 Pdr (47mm) and finally 6 Pdr (57mm).

The 6 Pounders in Naval service only had two kinds of projectile - common shell (HE) and armour piercing (solid). The Vickers 6 Pdr ammunition was 57 x 307 and there are images of this on the Web but I've never seen an image of the canister round.

The 6 Pounders were obsolete in capital ships around the turn of the century but lingered on in small vessels well into WW1 and even some survived in coastal defences into WW2.

Regards,

Charlie

I don't have any Vickers 6 Pdr images but there is a surviving Nordenfeldt 6 Pdr at�http://ammsbrisbane.com/documentation/nordenfelt_6Pdr_1.html - this gun was built around 1890.

Rectalgia · Legend

CharlieC wrote:
The torpedo boats of the time were quite small, iron hulled, low freeboard boats powered by a steam plant often derived from railway locomotives.�
...
The 6 Pounders in Naval service only had two kinds of projectile - common shell (HE) and armour piercing (solid).� ...

Ah, thanks (again) Charlie - we're talking about totally different classes of boat and I see the smaller wooden-hulled MTBs I was thinking of were only in British and Italian service during WW1 so the naval 6-pounder came into service before they were even thought of and was certainly not intended to counter those in British service.

I remain a little puzzled by the depiction of the (not quite) "common shell" or Steel Shell in Wikipedia (from the "Treatise on Ammunition" 10th edition 1915) which, as said, shows a F.G. powder bursting charge (4 oz blackpowder) for both Land and Naval service variants.� That wouldn't have been a lot of use against the (up to) 1,000 ton torpedo boats you properly point to as their intended Naval targets, I would have thought.

But that's all a little off-topic apart from illuminating the point that there wasn't necessarily much in the way of commonality between the Naval and the Land ammunition for 6-pounders.

P.S. Ah, but I see those Steel Shells were something like a hybrid between AP and the common shell and I believe we've (or I've) conjected before in these pages that the fairly insignificant base-fused black-powder charge might help to "hammer" the solid nose through armour.� One thing's for sure, it isn't HE, we must look elsewhere for evidence of more specific shells (or anything with "HE" in the designation) for tank use.

-- Edited by Rectalgia on Wednesday 11th of January 2012 10:56:11 AM

CharlieC · Legend

�

The Victorian torpedo boats were really small ships - a couple of examples:

HMVS Countess of Hopetoun 75 tons, 40m long, 24 knots max.

HMVS Nepean (2nd class) 13 tons, 20.4 long, 17 knots max.

Both of these boats were built of "galvanised Bessemer steel" which was supposed to be proof against the projectiles of Gatling guns and the Nordenfeldt machine gun.

The classes of torpedo boat built just before WW1 were much larger ships more like small destroyers. e.g.:

G132 (German) - 414 tons, 65.3m long, 28 knots

The WW2 MTBs and PT boats represented another solution where speed was the boats strong suit. By that time, of course, regular destroyers had taken over the role of torpedo attack in fleet actions.

"Common shell" is a usage more common in Victorian times - you could think of them as semi-AP rounds.

Regards,

Charlie

-- Edited by CharlieC on Wednesday 11th of January 2012 11:56:47 AM

jagjetta · Brigadier

was the 6lb gun in MKVs also made by Vickers?
JAG�

Gwyn Evans · Legend

Are we sure about the Vickers bit? I believe the gun in the Mark IV in Brussels has a makers plate that says Armstrong Whitworth.

Gwyn

MK1 Nut · Hero

This is the Information board on the gun at Bovi......

�

-- Edited by MK1 Nut on Thursday 12th of January 2012 09:09:08 PM

Morgoth · Major

According to Osprey new vanguard about Mark IV, it was equipped with solid shot ammo which could pierce 30mm of armour at 457m.

Rectalgia · Legend

higgins wrote:
Anyone know some specifics (and where images might be) concerning the ammo carried in Mark IV (males)? eg 6pdr armor-piercing, HE, and canister/case....

A quick browse of the British Ordnance Collectors Network indicates there could be some images there Dave.� You need to register to see all of what they have but from what I could see it looked pretty specific and promising.� Just have to wade through oodles of WW2 stuff to get to it (or ask).

I just might register there myself, one day (a few more immediate priorities in the meantime, my Goodladywife would doubtless remind me).

Steve

CharlieC · Legend

�

Sorry - my bad (to use an Americanism) - the Mark IV guns were Armstrong-Whitworth - licence built Hotchkiss 6 Pdrs. Vickers did make a 3 Pdr about the same time which was based on the Hotchkiss.

Interesting the tanks used the old mounting where traverse and elevation was performed by the gunner heaving on the gun. The naval mounts normally had gear driven traverse and elevation by the 1890s. I did find an image of a manually directed naval mount - this one is a Hotchkiss 3 Pdr from the 1880s.

Regards,

Charlie

higgins · Corporal

Thanks, Steve

The British Ordnance site was helpful. It answered nearly all my remaining questions- only "what does a British�57mm canister round look like," remains.�Considering there's probably not much need to update the technology (like with an AP round), I'm thinking those used with the Mark tanks were the same as those used with the navy (~1880+). I just didn't want to assume if I could help it.

Rectalgia · Legend

Glad that site was useful, I must look more closely myself (the missus will understand, I'm sure).� Assuming the tank canister rounds would be similar/identical in construction to the naval variety seems a safe bet.�

A little arithmetic indicates the acceleration of a projectile on firing identical ones from the tank gun (52" barrel, 1,350 fps MV) and from the naval gun in RN service (94" barrel 1,818 fps MV) would be practically identical at around 6,500 gravities in each case (just an extra 2 milliseconds to transit the longer barrel) so absolutely no need to modify shell construction on that score.

Steve

CharlieC · Legend

�

This might help...

A table of ammunition types for Nordenfeldt guns - the ammunition for the Nordenfeldts was similar to but incompatible with the Armstrong(Hotchkiss) 6 Pdr guns. The line of interest is for the 2.2in calibre.

The table was supplied by Rob Brassington who runs the�http://www.victorianshipmodels.com/ website and is from the Nordenfeldt

1884 trade book.

Regards,

Charlie

Rob · Legend

Has anyone had any luck finding a photo of the canister shot? Just bought a complete, I believe high explosive, 6 pounder round with strippable fuse. As you do.