Inglis 20mm Cannon
 

I ran across an article about this weapon a couple of weeks back, which included photos of a quad mount sporting them during WW2. A very nice looking design.

Does anyone have any information about this gun? The weapons were very secondary to the topic of the article and no real indication was given regarding the extent of production of the gun by Inglis. It was mentioned the gun was pitched to the British, but they were too heavily invested in the Oerlikon and Hispano to be interested. It would be interesting to know performance specs on the Inglis and how it really compared to it's two competitors.

David

Do you have Roger Lucy's "Secret Weapons of the Canadian Army? There are about 5 pages on this weapon. If you don't have it perhaps you could ask your local library to order it.
Clive

I am not sure this is much help did a quick internet search and found this

http://progress-is-fine.blogspot.ca/...t-gun.html?m=1

Clive: Thanks for that tip. I will see what the local branch can come up with.

Neil: Yes, that is the beast. That CMP was a trials vehicle used by Inglis while they worked out the details for the quad mount body. The article I read was about the armoured 6x6 the Canadians developed during the war, based on the Ford CMP 6x4 (with the trailing axle replaced with an active unit). Three versions were planned: 17-pdr gun tractor, APC and Quad 20mm Antiaircraft. A number of these vehicles went to England for evaluation during the war, and somehow, one Quad mount vehicle (minus the mount) turned up for disposal in Holland after the war.

David

Clive - update
 

Checked with the local library branch and they could not trace a copy so I went to the Service Pub site to order one. That 20mm intrigues me far too much not to learn more about it.

Best regards,

David

Your book is packed and will be in the mail tomorrow. Thnx.
C

David,

Can you tell us more about this, please?

H.

Inglis 20mm Quad
 

The early 1944 British decision to use only Oerlikon 20mm ammunition is what largely doomed the Inglis 20mm, which was designed (following British advice) around the Hispano-Suiza round. By the time the Inglis gun had been adapted to fire Oerlikon ammunition, the war was over. There is more information on the various projects using the gun at LAC: RG24 , Reel C-8414 File 9012-520,Quadruple ack-ack mount and RG24 Volumes 10061 and 10062 13/20 MM series, as well as among the ATDB reports at DHH (115.41013)

Attachment 65928 Attachment 65929 Attachment 65930 Attachment 65931

Inglis

Hanno: Give me a couple of days to borrow back the article in question from the friend that lent it to me and I will get back to you. I think there was actually a photo of the vehicle in question sitting somewhere in Holland, minus the quad turret mount at the rear.

Roger: Thanks for posting the photos. This gun is getting more interesting all the time and it is nice to know the concept of changing specs in the middle of a project and then killing the project, is not as modern a concept as we might like to think. ;)


David

Inglis 20mm
 

David,
Once you get your copy of my Secret Weapons book, you will see that that was pretty well par for the course.
Roger

There seems to be vastly more information available in relation to small arms than larger weapons which can be difficult to get any information on at all.

As I understand it the allies used two quite different 20MM rounds. One was the Oerlikon which was a short cased low velocity round that allowed its use in simple 'blowback' weapons. These had their origins in the WW 1 Becker which evolved into the WW 2 Mauser FF. This type of cannon can be identified by the large recoil spring around the barrel just forward of the receiver.

The other 20MM round was the Hispano which was much longer in the case, obviously had a much higher velocity and required the use of a locked breech mechanism. The guns for the two rounds were totally different which was, I would think, the problem confronting Inglis.

To stretch the discussion a little more. I would like to know where the Polsten fits into the scheme of things. This seems to be another weapon that not much is known about. The people who were involved in developing these guns must have been aware of each other. More so if they were Australian and Canadian.

David

David (motto):

I poked about a bit on the net as well, coming at it from a 20mm cartridge specs comparison angle. One site actually ID'd the Oerlikon round as also being used by the Polsten. The Hispano was a separate entity.

During the 1930's and throughout the war, quite a number of other 20mm cannons surfaced from a number of nations. Two distinct usages were quite clear: an aircraft weapon and a ground/surface based anti-aircraft weapon. From what I read, the Hispano was a very popular aircraft weapon, used outright or cloned by many nations on both sides during the war. On the other hand, the Oerlikon and Polsten seemed to be very popular as anti-aircraft weapons, particularly with Allied navies and ground forces.

I am by no means an expert on 20mm cartridges, but what I read appeared to suggest the Hispano round had somewhat better performance than the Oerlikon. One interesting ballistics site compared various 20mm rounds to the Browning .50 cal at 1000 yards. The Browning was still nicely flying along at near level at that range. The Oerlikon had dropped by about 8 feet and the Hispano was in the 6 foot range for drop.

From a performance perspective I can see why Inglis likely chose that round initially, as well as the British wanting to use it in the Inglis design for that reason. Maybe what changed British thinking and doomed the Inglis gun was the desire to keep the Hispano round an aircraft item. Since most of their Army and Navy 20mm stuff was already Oerlikon, they wanted to keep it that way with the Inglis.

Eagerly awaiting Roger's book for further enlightenment.

The 'other' David

Clive: The book arrived safe and sound in this mornings mail. Thanks so much also for the catalog. I have already flagged some extra reading items. Of course, that was your plan, wasn't it! :thup2:

Roger: Very interesting read on the Inglis 20mm. It reaffirmed my feelings the Hispano was clearly the superior ammunition, but the fact the British Army was so heavily invested in the cheaper, simpler (?) Oerlikon design, the Inglis was doomed. Can't help but think, however, that if the belt feed had gone into production and the Canadians could have floated the costs for putting into production for their own use, this item would have had a long, successful lifespan. Pity some clown scrapped all the items in storage. I guess that means no complete examples ever survived.

David

Sorry to revive such an old thread, but I stumbled across it while searching for information about the 20mm Inglis cannon, an example of which I spotted on a recent visit to the National Firearms Centre in Leeds, UK.

The information in this thread is very useful, but if anyone has more details of the gun, I would like to receive them.

For interest, shown below is a photo from the Ammo Photo Gallery on my website of some (not all) of the 20mm cannon rounds in service up to 1945. The Hispano aircraft cannon round is the 20x110 shown on the far right; the Oerlikon S is the 20x110RB next to it. As you can see, they are very similar but are definitely not interchangeable. Incidentally, both rounds are still in production to this day (those guns last a long time!).

You need to be careful in discussing 20mm Oerlikons as these came in various sizes. The Type S shown here was the biggest and most powerful of the WW2 versions and was used almost exclusively in AA guns, but there were also less powerful ones used in aircraft cannon: the 20x101RB (Type L, used mainly by the Japanese Navy in WW2 in the Type 99-2) and the 20x72RB Type F (used by Japan in the Type 99-1). The Luftwaffe used a variation of the Type F firing the 20x80RB ammo shown.

The postwar 20x128 Oerlikon is much bigger and more powerful.

http://quarryhs.co.uk/20mm1.jpg

From "The Machine Gun" Vol. 3 by George M. Chinn

Piotr

Following discussions with Roger Lucy and research in the UK National Firearms Centre in Leeds, I included a page on this gun ("Inglis EX-1-5000") in my new book: Autocannon: A History of Automatic Cannon and their Ammunition, which was published last year. See: https://www.crowood.com/collections/...ony-g-williams