CANNON..The Second World War Aircraft Gun

If you want to dig deeper try to get hold of a copy of Flying Guns WW2 by Emmanuel Gustin (the author of that page) and Tony Williams , possibly not the definitive book on WW2 aircraft armament (it just scratches the surface on turrets and sights) but by far the best reference I've seen so far on the gun themseves, beware that a lot of the info in it is also available on the author's web sites for free, but IMO the book is still worth reading.
Co-author Tony Williams also has a site and there are some very nice links there too.
BOOKS BY ANTHONY G WILLIAMS

 

Infantry Weapons and their Effects

http://www.youtube.com/watch?v=WT3b6sY34uI

 

From: http://ww2talk.com/forums/topic/50213-help-needed/

Firing the Hispano-Suiza cannon. Cor Blimey... I would not like to be on the receiving end of this!
Unbelievably good video. The last few seconds of sound bite will be with me for decades...

Tnx to everyone who restores and maintain all these important pieces of history! :S!

https://www.youtube.com/watch?v=bW0ob523z7k

 

That is a stunning clip, Fred. The word 'awesome' is totally devalued these days but certainly applies in this case.

I've always felt that the 'rocket-firing' aspect of the Typhoon, for instance, is over-rated. Just imagine being shot up in Normandy by a Squadron of them just with their cannon......

 

The 57mm gun used in the Mosquito mk XVIII was intended for anti shipping use. It added an auto loader to the 6Pdr (57mm) anti tank gun. There were no comparable British automatic weapons of that calibre on land or at sea.

I don't think it was easy to design the loading mechanism and the Tsetse 57mm installation seemed to work well. Looking at the chapter on Coastal command Mosquitos in my big book about the Mosquito (Sharp and Bowyer) the type was in use for just over a year and involved in dozens of anti shipping and anti-submarine strikes over the bay of Biscay and the Norwegian coast. I could only find two references to attacks being terminated through stoppages - and a few of Mosquito Mk XVIII air to air kills. It is superseded by the RP armed mosquito - probably because RP offers less risks to the aircrew who can engage from much further away.

The RAF had struggled to fit the 20mm Hispano Cannon into the Spitfire in 1940, feed problems being the reason. The job was given to the Molins Company (Lincolnshire?) which had no prior experience of building aircraft weapons, but were very well known for building cigarette vending machines. The MAP request to de Havilland to fit a 57mm gun was issued in mid march and the weapon tested on the butts in a mosquito nose on 29th April 1943. The aircraft was issued in September the same year.

The 57mm gun weighted 1,800 lb and the firing stresses were of the order of 8,000 lb. This wasn't the only big gun option considered. De Havilland seriously looked at fitting a 3.7"" AA gun into a mosquito with armour as a ground attack aircraft.

 

I do not care who you were... aircraft overflying aak aak emplacements or tanks or airfields under attack by intruder aircraft.
Who ever you were, if you were on the recieving end of this, your day just got very, very bad indeed. Indeed it did.

Thanks to those who started and participated in this thread.
By far and away one of my favorite subject study areas.

 

I have oft wondered about the life expectancy of artillery, cannon and their mounting systems that were not outfitted with incorporated recoil-absorbing designs.

Examples: Cannons not known for their in-built recoil mechanisms were installed in Spitfires, Mosquitos, Hurricanes, Typhoons just to mention a few.

Mosquito pilots are oft quoted as saying that an aircraft flying some 400 MPH or faster would come to a near halt within a second or so of firing these off.
The potential for airframe damage must have been a real concern.

Any experts out there who could fill in the blanks here?

Tnx!

 

A very good place to start reading up on the Hispano-Suiza Cannon is the exceptionally good wiki for it:
http://en.wikipedia.org/wiki/Hispano-Suiza_HS.404
and http://en.wikipedia.org/wiki/20_mm_caliber

That alone answered 90% of my questions.

 

It's often commented on at the Mosquito Museum that these aircraft - in common with nearly all operational WWII types - were built under 'emergency' conditions with not a great deal of thought being given to longevity. The average 'lif expectancy' of an airframe was often thought of in months, not years.

However, I've never seen any official guidelines about this, so I'll keep it in mind and see if I can ask someone who knows more about it than me......

 

The Big Mosquito book states that the 57mm barrels suffered wear after about 300 rounds. An anti tank gun isn't expected to fire a lot of rounds in war time. Aircraft do not need quite the same recoil systems as a tank or ground fired weapon. Air is a fluid medium. No amount of springs or pistons can counter Newton's third law.

 

300 rounds for such a small caliber weapon looks a bit too little, the Ordnance QF 6 lb was not an extreme design like the soviet gun of the same caliber.

I believe there was possibly another 6lb autofeed gun in the British arsenal, coast defence installations had a twin 6lb mount for use against light craft and they were used pretty effectively at Malta, a 6lb was also mounted on some MGB and Fairmile D MTB/MGB though that one looks a lot like the tse tse and wiki calls it Molins.

http://en.wikipedia.org/wiki/Fairmile_D_motor_torpedo_boat

But I'm not sure the coastal guns were related to the AT gun, IIRC the British called any 57mm bore weapon a 6lb, the Hotckiss gun used in the WW1 "male" tanks was a 6lb and the Malta guns were already there in 1941 when the Army still had to make do with the 2lb. It could be that some 6lb built before they stopped production in favour of more 2lb were turned to coast defence use, but if the coastal guns also had Molins produced autoloaders the story of the "no previous experience" at the time of the Mosquito design is mith.

EDIT: the coast defence guns were a differrent beast but had no true autoloader just man operated quick loader, they still achieved a quite respectable 40 rpm.
http://www.fsgfort.com/uploads/pdfs/Public/British%20Coastal%20Artillery%20P.pdf

 

Was it possible to change the barrels out of cannon installed in Aircraft? Leaving the remainder of a functional piece of artillery to carry on in its designed role and location?

Secondly:
I wonder if there is a "Guinness Record" list for each aircraft type for Intruder Missions?

At first glance, it does not look like anyone has published a study on this area...

 

Re 1. I checked the big blue book and the test in 1943 revealed wear after 300-500 rounds.

Re 2 Apparently the 6 Pdr gun using the Molins autoloader was a bit of a solution looking for a problem, having been designed in (1940-42?) as the armament for some form of Portee or Tank destroyer 6 pdr which was then scrapped. http://www.quarry.nildram.co.uk/Molins.htm This is Tony William's website .It isn't a primary source, but his research is very good,

Note the comments on the comparison between the manually loaded US 75mm in the B25 and the 57mm Molins

 

The big blue mosquito book has a listing of kills and irts own record beakers list of "noteworthy Mosquitos" MM466 was used to shoot down 11 German aircraft, over north west Europe a night fighter rather than bomber support. .

 

Up at the Mosquito Museum today, thought I'd take some photos of our Molins 6-Pounder especially for this thread...










And I thought I'd offer my own comparison of a 6lb projectile with a 0.50cal for comparison...

 

Great post, Martin, I am really curious about the auto loading 57mm. Was the installation in the Mosquito considered a success? Given the size of the cannon and airframe was it possible to reload, what ammunition capacity did it have and lastly are the references of it's use in combat ?

I presume it was ab anti-ship piece but perhaps it had other uses as well, could one reasonably expect to hit a tank or train ?

Gaines

 

The big blue mosquito book claims it was a success.


http://www.quarry.ni...o.uk/Molins.htm

 

Well I am a bit embarrassed, I thought I had read all of Tony Williams' works but missed this article and it answered everyone of my questions !

Many thanks and another reason to like this forum so much.

Gaines

 

Hello Gaines

The installation was considered a reasonable success, given that development had only limited priority. Really, it was intended only for anti-shipping use rather than tanks etc ( as we've discussed before, 'anti tank rockets' etc relied mainly on blast effect rather than pinpoint accuracy ).

If you can find a copy, I really do recommend getting hold of Des Curtis' book 'A Most Secret Squadron' ( Skitten Books 1995 & 1996, ISBN 9 780952 524700 ).. The author ( who I had the genuine privilege to meet ) was actually there, and tells the whole story of 618 Squadron.and, in the chapter ' New Artillery Of The Sea', describes at first hand the development and use of the 'Molins Gun'.

 

Don't be embarrassed it gave us a chance to bring up his site again so that anyone not familiar with it has less excuse to be so. IMO it's one of the most useful sites on the internet for such topics.