National Maritime Museum gun turret model

[JFC Fuller]

Browsing the NMM ships models collection looking for something else today i stumbled across this:

http://collections.rmg.co.uk/collections/objects/68917.html

It certainly looks post-war and fast firing. The glazed section beside the gun is reminiscent of sextuple bofors mounting, the 3" Mk 6 and of course Green Mace. The overall footprint of this mounting is reminiscent of the 4" guns supplied by Vickers for the Chilean Almirante class. The NMM gives the following description:

A working model of a gun turret made in wood, painted a uniform grey, with metal working parts and plastic fittings. The rear section of the turret, is a half-hexagon in shape and can be removed to show the elevating mechanism. The turret is an elongated hexagon shape in plan view, the underside of which has an integral shallow wooden turntable with a rounded metal pivoting pin at its centre. The gun barrel and housing is made of wood and can be elevated to almost 90 degrees. On the right-hand side of the barrel is an enclosed cockpit, glazed on three sides with a pitched glazed roof canopy. The gun is linked to the elevating mechanism by two chains worked over a drum.

I would add that the gun appears to have a dual feeding mechanism which reminds me of Green Mace though there are no signs of water cooling (that I can see) on what is a detailed model. Does anybody have any thoughts or know more?

 

[Tony Williams]

Interesting. Not seen anything like that before.

 

[Abraham Gubler]

The single recuperator over the barrel looks like the 3.7” AA gun. Also the two feed systems appear to be dropping rounds onto a Ratefixer style tray on either side of the breech. Perhaps a naval mount for the 3.7?

 

[smurf]

The central part of this mounting that pivots vertically (roughly wedge-shaped plus the barrel) looks rather like the drawings of Zenith and Marquardt versions of DACR at 34 or 40mm. These usually show things like calculated recoil forces, but it is never clear on those I have seen how the gun would be mounted on a ship. This might be the answer. The whole turret is not unlike the 57mm twin DACR. Still can't get at my photos though.

 

[Petrus]

Still can't get at my photos though.

Hopefully your computer will be running again.

P.

 

[Tony Williams]

The central part of this mounting that pivots vertically (roughly wedge-shaped plus the barrel) looks rather like the drawings of Zenith and Marquardt versions of DACR at 34 or 40mm.

I'd be grateful for any information you have about these.

 

[uk 75]

Found this interesting gun turret model on the excellent National Maritime Museum site

http://collections.rmg.co.uk/collections/objects/68917.html

Anyone know more than they appear to?

Edit : Topics merged and picture added

 

[Grey Havoc]

The reported naval version of Green Mace?

 

[Tzoli]

More like the 4inch Mark N/R mount:




(drawing resized)

 

[Abraham Gubler]

Its the original design for the Vickers 4" Mk N mounting called the Vickers Universal Mounting. There is an article in "Warships 2013" by Peter Marland (ex RN WEO) about this gun which has drawings of the original design that match this model. It used the same L45 barrel as the legacy Mk 16 4 inch gun which was later replaced by a new L62 barrel in the production weapons for Chile. The production version also enclosed the entire mounting in the gun house as this version as the two ammunition hoppers mounted outside. The hoppers were also angled to the mean of the gun's elevation and here they are horizontal.


This system is a great gun and could have made a significant improvement to the RN's destroyers and frigates if it had replaced the Mk 6 4.5 inch gun and the later Mk 8. Lighter, cheaper, more reliable, greater weight of fire and so on. The only problem about such a 'What If' is the Iranians would have had them on on their Vosper Mk 5s and that would have cost the lives of a lot more merchant sailors when they were shooting up, almost at random, cargo ships in the Persian Gulf in the 1980s.

 

[Abraham Gubler]

More like the 4inch Mark N/R mount:

That's a large scan of a copyrighted image (A.D. Baker III's) and its not this forum's policy or good behaviour (ie illegal) to upload such to the internet. You should really delete it and replace it with a lores scan (under 480 pixels wide) to preserve the rightful ownership of the artist who drew it.

 

[Tzoli]

Its the original design for the Vickers 4" Mk N mounting called the Vickers Universal Mounting. There is an article in "Warships 2013" by Peter Marland (ex RN WEO) about this gun which has drawings of the original design that match this model. It used the same L45 barrel as the legacy Mk 16 4 inch gun which was later replaced by a new L62 barrel in the production weapons for Chile. The production version also enclosed the entire mounting in the gun house as this version as the two ammunition hoppers mounted outside. The hoppers were also angled to the mean of the gun's elevation and here they are horizontal.


This system is a great gun and could have made a significant improvement to the RN's destroyers and frigates if it had replaced the Mk 6 4.5 inch gun and the later Mk 8. Lighter, cheaper, more reliable, greater weight of fire and so on. The only problem about such a 'What If' is the Iranians would have had them on on their Vosper Mk 5s and that would have cost the lives of a lot more merchant sailors when they were shooting up, almost at random, cargo ships in the Persian Gulf in the 1980s.

Really interesting! As you can see the Vickers firm included this type of weapon for many of it's export cruiser designs. Sadly Navweaps side does not contains info about the gun and mounting as it have a different Mark N mount listed:
http://www.navweaps.com/Weapons/WNBR_4-40_mk7.htm
Looks like it is a good idea to get hold of that Warship issue?

 

[Tzoli]

More like the 4inch Mark N/R mount:

That's a large scan of a copyrighted image (A.D. Baker III's) and its not this forum's policy or good behaviour (ie illegal) to upload such to the internet. You should really delete it and replace it with a lores scan (under 480 pixels wide) to preserve the rightful ownership of the artist who drew it.

I bought the book, did not said a single thing about I draw it or even selling it, just posted it as the mounting looked like the ones used on this export cruiser proposal. Also people should know more about the never were designs!

 

[Abraham Gubler]

Really interesting! As you can see the Vickers firm included this type of weapon for many of it's export cruiser designs. Sadly Navweaps side does not contains info about the gun and mounting as it have a different Mark N mount listed:
http://www.navweaps.com/Weapons/WNBR_4-40_mk7.htm
Looks like it is a good idea to get hold of that Warship issue?

The Conway Warship series, now edited by John Jordan, are great resources. Most of the information on unbuilt ships of WWII and the post war period that we all know were first published in these books in the 1980s and now as an annual they keep coming up with good stuff. It can be a bit frustrating the wide coverage from the 19th century to modern times and the price is stiff. But its quality stuff.

The 2013 edition has an article on British post war ship offers to South America and an article on the Vickers 4 inch gun including its fire control system as fitted in the Chilean destroyers. The 2014 edition follows up the 4 inch gun article with another on British post war fire control systems and the 2015 edition on British post war guns and missile launchers. All good stuff.

I bought the book, did not said a single thing about I draw it or even selling it, just posted it as the mounting looked like the ones used on this export cruiser proposal.

Actually it does on the page before the contents where it says the book is copyrighted and all rights reserved and no reproduction allowed and so on. Under international copyright law you are able to present some limited copies for the purpose of review and education and the like but high resolution scans falls outside what is legal.

Also many books include reproductions of artwork that is not copyrighted like US Government drawings or time expired imagery. This stuff can be freely copied and distributed as long as you make sure it doesn’t include any original work. The drawings by AD Baker III are original works and are fully copyrighted. Just like your own drawings which you can sell or freely give away if you want.

Copyright does not extend to information and ideas presented in articles. It does cover the word arrangements and original stories so you can’t copy text verbatim or rebadge someone’s stories.

Also people should know more about the never were designs!

Sure which is what this webpage is all about. But people still own their original work unless they decide to give it away. Professional writers and artists rely on their copyright protection to make a living off their work. Without that living, or supplement to it, they often don’t have the time to go and research the information, analyse it and package the results into a book or article so we don’t get to find out about it. Without copyright Norman Friedman would be some guy down at his local pub who could tell you everything about 20th century warships and not an author or 10 or more books that anyone can access to find out the same. And Dave Baker would be similar but who also had an amazing collection of drawings at home that he might let you come around and look at if you were lucky.

 

[Tzoli]

Looks like this mounting is very similar to the Vickers 4inch Mark Q mounting used on the Chilen Almirante Williams class destroyers:

The mounting is fully enclosed:

http://www.navweaps.com/Weapons/WNCHL_4-62_Vickers.htm

 

[Abraham Gubler]

Looks like this mounting is very similar to the Vickers 4inch Mark Q mounting used on the Chilen Almirante Williams class destroyers
http://www.navweaps.com/Weapons/WNCHL_4-62_Vickers.htm

Mark N and Mark Q are the same thing (sort of). The mounting was called the Mark N(R) and the 62 calibre barrel gun was called the Mk Q. The gun mount was also called the Vickers Universal Mount. The early version of the gun mount (as in this model) was pithced to the RN in 1953 and was based on the Vickers design for a land servicec anti aircraft gun called the "X1". The model is of this "X1" derived mounting aka the Vickers Universal Mount , which was later developed into the Mark N(R) as fitted to the Chilean ships. This version of the mounting was to be fitted with the Mk 16 4"/45 gun hence the shorter barrel.

 

[Tzoli]

That is good to know, now at least I know how would these turrets really look like other then just outlines for the export cruiser designs.
Looks like quite a good turret, wonder why not used on British ships...

 

[Abraham Gubler]

That is good to know, now at least I know how would these turrets really look like other then just outlines for the export cruiser designs.
Looks like quite a good turret, wonder why not used on British ships...

Not invented here (in the Navy), wrong place/wrong time, etc.

 

[Tzoli]

That is good to know, now at least I know how would these turrets really look like other then just outlines for the export cruiser designs.
Looks like quite a good turret, wonder why not used on British ships...

Not invented here (in the Navy), wrong place/wrong time, etc.

I meant the 4inch Vickers Mark Q/N gun and mount.

 

[Tony Williams]

Several months ago I sent the following email to Conway for the attention of John Jordan, editor of Warship. Sadly, no response to date:

I have some comments and questions for Peter Marland concerning his notes on the Vickers 4 inch Mk N(R) on pages 174-177 of Warship 2013. I would be grateful if you could pass these on to him.

My main interest is in the ammunition used by this gun. I note that the gun was originally designed to use the standard Mk 19 45-calibre ammunition, but that this was later changed to a 62-calibre barrel. According to the data I have, the Mk 19 ammunition fired a 15.9 kg shell at 811 m/s, while the Mk N(R) fired a 16 kg shell at 900 m/s. That represents an increase in muzzle energy of 24%, which is quite considerable. I would be very surprised if such an increase could be achieved merely by increasing the barrel length – I believe that a cartridge case containing more propellant would be required.

Which brings me on to the Green Mace link. To provide some more information than is in your Note, the 4" and 5" versions of Green Mace were both prototypes, the ultimate version was intended to be a 5.68 inch (144mm) smoothbore (never built). The 5" smoothbore firing HEFSDS ammunition was built and tested, but problems were experienced with this ammunition in the 4" version so a rifled barrel, firing conventional spin-stabilised shells, was made and tested instead. I have some photos of both the 5" HEFSDS and 4" spin-stabilised ammunition.

The overall length of the 4" Green Mace round with a conventional shell was almost exactly the same as the Mk 19 (1,140mm vs 1,146mm) but the other dimensions are different; the Green Mace round has a shorter but fatter cartridge case, which will almost certainly contain more propellant. The dimensions of both cases are as follows:

4" Green Mace: 670mm long, with a rim diameter of 173mm

4" Mk 19: 730mm long, with a rim diameter of 150mm.

The shorter case for the Green Mace allows the shell to be a better shape within the same overall round length, with a longer ogive for improved ballistics.

I believe that the larger Green Mace case, in conjunction with the longer barrel, would be able to achieve the 24% increase in muzzle energy stated for the Mk N(R).

So, my question is, have you come across any official drawings of the Mk N(R) ammunition which would allow a definite identification to be made? If it helps, the following markings are on the 4" Green Mace round in the photo:

Cartridge case headstamp:

RLB 1955 D2/L/6750/E


REQN D2/52/903


CODE 46/30/221


Markings on projectile:

C J 509


102 MM QF HE 4"


D2 ' L ' IC ' 310 ' E


D2 152 ' 804


AMEND 25


A ' 321

Incidentally, I found it interesting that the calibre is marked as 102mm first, and 4" afterwards. This made me suspect that it could have been made for a foreign customer, and I had tentatively tagged this as the possible round used by the Vickers guns in the Chilean destroyers even before I read your article.

 

[JFC Fuller]

I know we have effectively settled this but I can now confirm beyond doubt that the model in the NMM is the early version of the Vickers 4" mount as ultimately sold to Chile as I found a file in the UK National Archives that included a large diagram of exactly this mounting.

Tony,

This probably doesn't help you at all but the file I was looking at referenced replacing the earlier shorter barrel with the barrel from the X1 4" prototype Army AA gun.

 

[covert_shores]

Very cool, kudos for the primary research

 

[Jemiba]

I know we have effectively settled this

No theme should be put aside without a definite answer like that . Chapeau (kudos) and thank you !

 

[Grey Havoc]

I know we have effectively settled this

No theme should be put aside without a definite answer like that . Chapeau (kudos) and thank you !

It's always nice to have the t's crossed and the i's dotted.

 

[Tony Williams]

Not all of them, for me - still the ammo question left uncertain.

 

[Tony Williams]

Tony,

This probably doesn't help you at all but the file I was looking at referenced replacing the earlier shorter barrel with the barrel from the X1 4" prototype Army AA gun.

Actually that is helpful, since the chamber into which the ammo has to fit is formed as part of the barrel (with a few exceptions, like revolver cannon and the 40 CTWS). So fitting a barrel from another gun almost certainly means using that gun's ammunition too.

 

[Abraham Gubler]

Several months ago I sent the following email to Conway for the attention of John Jordan, editor of Warship. Sadly, no response to date:

I have written down that the cartridge for the 4"/62 was 102x670mm. I don't have written down beside where this is written down where this that I wrote down was written that I read so as to write it down. Bad note taking on my behalf. Also there is this (see attached) from N.J.M. Campbell's article series "British Naval Guns" as published in Conway's Warship back in the 1980s.

 

[Abraham Gubler]

Incidentally, I found it interesting that the calibre is marked as 102mm first, and 4" afterwards. This made me suspect that it could have been made for a foreign customer

Could be a NATO thing: the use of metric measurements first.

 

[Tony Williams]

I have written down that the cartridge for the 4"/62 was 102x670mm.

Excellent - more evidence pointing in the same direction.

I don't have written down beside where this is written down where this that I wrote down was written that I read so as to write it down.

Also there is this (see attached) from N.J.M. Campbell's article series "British Naval Guns" as published in Conway's Warship back in the 1980s.

Of course - I have the entire set of Warships and should have thought to check....too many books, not enough time!

Could be a NATO thing: the use of metric measurements first.

I don't think so - I have a 1978 dated 4.5" naval gun case and the headstamp only says "4.5". No mention of 114mm.

 

[starviking]

Could be a NATO thing: the use of metric measurements first.

I don't think so - I have a 1978 dated 4.5" naval gun case and the headstamp only says "4.5". No mention of 114mm.

But wasn't the only other NATO navy using 4.5" the Dutch? Also, they were getting rid of it at the time, modernising the Van Speijks to 76mm. Perhaps there was no need for metric on such rounds, as there was no commonality to serve.

 

[Tony Williams]

But wasn't the only other NATO navy using 4.5" the Dutch? Also, they were getting rid of it at the time, modernising the Van Speijks to 76mm. Perhaps there was no need for metric on such rounds, as there was no commonality to serve.

But there was no commonality over 4" rounds either, so why give them a metric designation?

 

[starviking]

But wasn't the only other NATO navy using 4.5" the Dutch? Also, they were getting rid of it at the time, modernising the Van Speijks to 76mm. Perhaps there was no need for metric on such rounds, as there was no commonality to serve.

But there was no commonality over 4" rounds either, so why give them a metric designation?

Non-Nato metric using nation makes sense.

 

[awhalen61]

I believe this thread has solved the mystery of the mountings shown in this 1950s Almirante Lattore refit proposal:



Given the date of the proposal and the information provided in this thread, I believe it is a twin 102mm/45 Mark N BD mounting- although until i can see the original plan, this is still just an educated guess.