6 pdr twin coast defence guns in WWII

[RodB]

I've come across some photographs labeled as 6 pounders, shown in twin coast defence mounts, the one at Hurst Castle purporting to be "built" in 1936, the other from IWM labeled as maintenance in 1943. The mounts don't look anything like the WWI Hotchkiss naval mount, which had recoil tubes alongside and just below the barrel. These later pictures show recoil tubes above the barrel and what looks like a long sleeve, lacking in WWI pictures. Are these what Ian Hogg describes as Hotchkiss 6pdr Mk I+++, being single-piece barrels manufactured on the cheap for the Navy early in WWI, and in 1917 brought up to scratch by rebuilding by boring out, lining with an A tube & shrinking a B hoop around it ? See below :

Hurst Castle, labeled as "manufactured in 1936" :

From the IWM collection, labelled "1943 Work being carried out on a 6 pounder twin coastal artillery gun"

Were these later twin mountings in fact recycling old Mk I Hotchkiss 6 pdr 8 cwt guns on totally new mountings ? Or some different 6 pounder altogether ? I'm aware a totally new 6 pdr 7 cwt came out about 1938, and became the anti-tank and Molins gun, but this had a single large recoil tube below the barrel & looks totally different.

All the other pictures I've seen of the 6 pdr Hotchkiss look something like this one below, with straight barrel, no sleeve, & the recoil tubes are just visible below the barrel :

thanks

Rod

[ionia]

Could this be the 6pdr/10cwt QF Mark 1 which John Campbell ("Naval weapons of WW2") describes as a coast-defence gun intended for use against MTBs and, in modified Mk 1 mountings, fitted to some V & W destroyers in WW2? Unfortunately the naval mounting has a very extensive shield and this prevents identification of the gun from photos of the ships concerned.

This weapon had an A tube and part-length jacket and breech ring with SA vertical sliding breech block. Recoil was 12" and rate of fire 36 rpg per minute . Elevation +80deg to -10deg. The coast defence mounting was hand-worked.

[RodB]

Indeed yes, thanks ! a quck search turns up lemairsoft's description which seems to match. Do you know anything of the ancestry of this gun - based on the Hotchkiss ? Unlikely to have come fully-formed out of somebody's head ! The overall setup looks like a scaled-down version of the twin 4 inch.

This picture of HMS Mackay, 1943, at the IWM is described as 6 pounders, is this the type of turret you mean ?

Rod

[ionia]

No indication of its ancestry. The implication is that it was designed between the wars.

[T8HANTS]

Is this the beast you are after?

This hand book was a Ian Hogg's own copy, which he gave to my father because of our interest in the twin six mounts on the top of Ft Albert on the IOW.

There is some very nice training film in the IWM, BTW.

Gareth

[Repulse]

Be careful with English Heritage properties' armaments !

At Dover Castle there is an Ack-Ack gun which is part 3.7 and part 105mm or something similar !

http://www.flickr.com/photos/robertkilpin/2451861285/

They are OK with your 32pdr smooth bores !

[Ness Battery]

TBHANTS - tried to send a message but not allowed yet.

I'm interested in the twin-six - and have been looking for that manual for some time!

There were several twin-sixes installed around Orkney and I have some great photos from the IWM of the one at Links Battery covering the western entrance to Scapa Flow near Stromness.

One particular piece of information I am trying to confirm is the gun's rate of fire.

I have seen several different figures given for this. The wikipedia entry and Tony DiGiulian's excellent NavWeaps site both give a figure of 18 rounds per minute, but not sure if that is the two guns combined or if the total rate would be 36 rpm.

In a couple of sources it suggests 72 rpm but this sounds unlikely. One local guide book even suggests 120 rpm!

Anyway,if you could shed some light on this I would be very grateful.

[Ness Battery]

Here's an image of the inside of the twin-six at Links Battery near Stromness, Orkney.