40 mm Bofors AA guns made in GB and US

[Rob Fast]

as you know I am lapping up all of the Bofors info being generated on this thread, but my replies are few and far between, I am getting real busy on my golf course. 2 to 4 inches of rain expected tonight, flash flood warnings, and I have a big creek running thru my track! Yes, it all seems to be operational, but I have not manuals on it. In the next week I will try and supply you with a little more detailed info, and pics, keep your expert info coming, this is great. A quick question. I have been testing my Bofors with blank/ black powder rounds, in antisipation of a salute to veterans at the Winnipeg Assiniboine Park , Friday July 1, CANADA DAY. What do I use to clean the pinned barrel? Soap and water? That powder turns everyting rusty, quickly. Suggestions? Cheers Rob

[sapper740]

What do I use to clean the pinned barrel? Soap and water? That powder turns everyting rusty, quickly. Suggestions? Cheers Rob [/B][/QUOTE]


Hey Rob, I've shot a lot of black powder in my day both in a model 1884 Trap Door Springfield and when using .44 S & W. Special ammo loaded with black powder in a Ruger Vaquero for authenticity at Cowboy Action shoots. The only thing that cleans BP residue is warm, soapy water and a lot of elbow grease! After cleaning I dry the barrell thoroughly before running a swab soaked in gun oil to protect the bore. Here's something you might want to try; mill a sub-calibre insert that holds a.50 BMG blank round for your gun. You'll get a loud report with no large, smelly cloud!

[Godwin Hampton]

Rob,

In the good old Black Powder days ( what's so good about dirty, smelly, foggy and corrosive Gunpowder? ) the Drill Book ordered copious amounts of Hot water to sponge out the barrel as soon as possible after firing. The 'sponge' was a short-bristled brush the size of the bore, attached to a long stave to reach all the way into the bore.

Sapper's suggestion is brilliant. I was thinking about something on those lines, using a piece of stainless steel tubing, plugged at one end,and loaded with six or eight charges of smokeless or black powder or a mixture of both.
The charges would be individually packed and bound with string, and connected together with a short fuse to set them off in quick succession ( half-second intervals ).

The first set off would obviously be the one nearest the muzzle, possibly using an electric igniter. I would someday like to try out a torch bulb, carefully broken to leave the filament intact, with wires soldered on and buried in the powder. Connecting the wires, via a switch, to a car or motorcycle ( or golf caddy??) battery should set the first charge off, starting the chain reaction.

This is up to now all theory, and I will seek the advice of a pyrotechnic expert, so DO NOT TRY THIS AT HOME!!!! ( He, He.)

[Tony Smith]

Originally posted by Godwin Hampton
Now we can really start delving into this exotic piece of mind-blowing machinery! Do all the linkages on yours work? Did you study what happens when you muck around with those bits and bobs? Have you got any literature on how it ticks?

The Australian version was strangely a mirror version of the one in Rob's picture (No Down Under jokes, please). I have the Handbook for this and it does go into some detail. The actual sights themselves are very unusual to find on an existing gun, most seeming to have the plain spiderweb or "Stiffkey" sights.

[Godwin Hampton]

Tony,

Is the Handbook the 1941 version published by the War Office on 13/ 8/ 41? That handbook covers all versions in British Army service, whether bought from Sweden ( or Poland or Hungary ) or produced in Great Britain.

The Bofors Course and Speed Sight was only fitted to many, or possibly most, of the Guns ordered from Bofors.

The Guns produced in Great Britain, and later in the Commonwealth Countries,used Forward Area Sights when operating at direct laying, and the Kerrison Predictor when operating at indirect laying. The Predictor would lay the gun through a "remote control" system using electric motors/oil units to turn and elevate the Gun. Only the loader would remain on board, to feed and fire the Gun. Pretty impressive for 1941, eh?

Around 1944, the predictor gave way to the Correctional, or 'Stiffkey' sight on British, Commonwealth, and even American Guns. Towards the end of the War, RADAR replaced the Predictor on some of the Guns still fitted with the Oil Units, giving them the capability to engage aircraft invisible to the layers.

[Tony Smith]

Originally posted by Godwin Hampton
Tony,

Is the Handbook the 1941 version published by the War Office on 13/ 8/ 41? That handbook covers all versions in British Army service, whether bought from Sweden ( or Poland or Hungary ) or produced in Great Britain.

Yes, that's the manual I have, but it also has some loose leaf and pasted in Aust amendments.

The Bofors Course and Speed Sight was only fitted to the Guns ordered from Bofors.
The Guns produced in Great Britain, and later in the Commonwealth Countries, used Forward Area Sights when operating at direct laying, and the Kerrison Predictor when operating at indirect laying.

Ah! That would explain the lack of C+S sights on Aussie guns. I have seen many with Stiffkey sights and even a predictor unit.

[Stellan Bojerud (RIP)]

1. Am I right in thinking that the Bofors calculator could be turned 360 degrees around? That could be why Tony´s picture is a "mirror" version.

2. Tony´s picture is showing a Bofors FC m/35.

3. Rob´s is a Bofors FC m/38.

4. The first batches of Bofors guns delivered to UK from Belgium, Poland and Sweden had "Polish sights" = Bofors FC. The latter batches delivered from Poland to UK had no sights, since they should be used with the No 3 Kerrison Predictor and also be fitted by British crosswire-sights.

[Godwin Hampton]

Stellan,

Your identification of Tony's picture as an m/35 and Rob's photos as the m/38, in my opinion provides the solution!

Since the British ordered Guns fitted with this type of sight before 1938, they would be fitted with the m/35 sight. Those ordered last were fitted with oil units for the Kerrison Predictor (and forward area sights, but I agree with you that these may have been added by the British). Bofors continued development to the m/38, but these were sold to countries other than Great Britain.

The 1941 Handbook quoted by Tony has Plates showing three versions of Swedish/Polish Bofors Guns, thus;

Ordnance Mk.1 / Mounting Mk.1 / Platform Mk.1 (plates 11 to 13)
This version has bearing and elevation receiver dials, no sights, and 5 spoke/5 stud wheels

Ordnance Mk.1 / Mounting Mk.111 / Platform Mk.1 (plate 14 )
This version has Bearing and Elevation oil units, Forward Area Sights, and 8 spoke/ 6 stud wheels.

Ordnance Mk.1 / Mounting Mk. 1A / Platform Mk.1 fitted with the Bofors Course and Speed Sight, seen on its own (plates 45 & 46)

There is also a description and pictures of parts pertaining to the Mk.1B Mounting (a Mk.1 modified so that it could be fitted with the oil units if required.) and the Mounting Mk.11, similiar to the Mk.111 but with elevating and traversing handles that had to be removed for power operation, not like the Mk.111 handles which only required unclutching.

Unfortunately I do not yet have the expertise to post these pictures, but have not given up yet!

[Godwin Hampton]

Originally posted by David_Hayward
Has anyone got a photo of a CDSW Bofors tractor please?

David,

Have a look at www.canadianregister.co.uk Look through the MVT Kemble photos, particularly photo M010.

[nuyt]

In St Petersburg Artillery Museum

[Stellan Bojerud (RIP)]

The S:t Petersburg picture is of a 37 mm M 1939.

The Soviet Union bought at least one 25 mm m/32 Bofors gun and license rights.

The engineers L.A. Lokev and M.N. Loginov of No 8 Artillery Factory near Moscow made an upscaled version in 37 mm known as M 1939.

These were also produced in large quantities by factories 4 Krasnojarsk, 8 Moscow and 586 Kolumna.

After WW 2 this type of gun was also produced in China and Poland.

[nuyt]

That's funny, though my Russian is not perfect I understood from the small notice in front on the gun that this was a Bofors 40mm. There were other guns marked 37mm. They must have made a mistake?

[Stellan Bojerud (RIP)]

I think you are right.

Looking closer on the wheels and the outriggers I tend to think that it is a 40 mm US-made Bofors. Lend-lease I suppose. In such case made by Chrysler Coorporation. Chrysler made guns were the only type that had the welded version of the original riveted MK 1 type which if I remember right was US type M 2.

I was confused because the gun has russian sights. Could have been added later to facilitate training.

[Godwin Hampton]

Eric,

In my humble opinion it is a very American, very 40mm Bofors!

[John McGillivray]

Here are a few more photos of the 40mm Bofors in service with the Canadian Army.

The first is of the 3rd LAA Regt. RCA, at Bexhill on the South Coast, in the UK.

[John McGillivray]

Another Bofors on the South Coast.

[John McGillivray]

A Bofors and its tractor being help by a dozer across a flooded stream in Italy.

[Alan Brock]

There is a picture dated Oct 6th 2004 showing a Bofors next to a SCR584 radar set.
The radar shown is not in fact an SCR584 but the pictures attached are !

and another SCR584 pic...

[Tony Smith]

Time to revive this interesting thread.

Another Bofors has been located (more on that story later..), and can anyone ID the manufacturer (Stellan, Godwin??)

The platform is made by BPM Ltd in 1941:

[Tony Smith]

While the Gun Casing is made by AR in 1942:
Any ideas who these manufacturers may be?

[Godwin Hampton]

Tony.
The second picture refers to the mounting, so you still have to unearth the third plate stuck to the right hand front of the actual gun casing, starting ORD...

The PLAT ( platform ) plate in the first photo shows that it is a Mk11 model, not the original Swedish Mk1. This model, designed in England by Nuffield Mechanisation, used running gear off the Morris Commercial PU 8 cwt. truck. Hope the 9.00 - 13 tyres are in good nick!

These Mk11 models were produced in England, Canada and Australia, and many sub-contractors were involved.

According to the Terry Gander book, in Canada the main producer was the Dominion Bridge Company at Vancouver. In Australia the Government Ordnance Factory at Maribyrnong, Victoria with sub-contractors including the Ford Motor Co., H.V. McKay, Massey-Harris, and the Paton Brake Company amongst others.

Unfortunately none seem to fit the bill.....

Eagerly awaiting more on this Bofors

[Stellan Bojerud (RIP)]

I suggest AR stands for:

A.Reyrolle & Co Ltd, Hebburn-on-Tyne
Late 1941 – Dec 1943 totally 1.580 guns made.

Greetings

Stellan

[Hanno Spoelstra]

Wehrmacht Police Troops w/ Captured Bofors AA Gun!!! Item number: 290057375950

[alamotex]

Have only recently followed this thread. Does anyone have info on the trainer dome which was used to simulate gunlaying ? or was it only used for aircraft recognition ? I seem to recall that images were projected onto the curved ceiling and that the sound effects were realistic. Brian Mendes.

[Godwin Hampton]

Brian,
Dome Trainers were definitely used by the British Army for gunnery training, with a Bofors in the centre under the hemispherical dome, and a projector sending moving images of planes to be aimed at.

I have a User Handbook for Apparatus, Dome Training, No.6 and "Portobel", dated 1962. The introduction says "This apparatus is an anti-aircraft gunnery trainer developed on principles similar to the Apparatus Dome Training No.4. Used in conjunction with a service dome, it provides a substitute for field training with aircraft co-operation when training anti-aircraft gunners on L.A.A. weapons. It provides also realistic gunnery practice under conditions closely resembling those experienced in actual warfare."

Half a dome survives still in situ at the Malta War Museum, which is housed in a building that was originally built as a Territorial Army Drill Hall. No doubt the dome would have been very useful for evening training sessions, or when the weather did not allow outdoor training. The dome is made out of plywood stuck on to a wood framework, probably produced locally to a W.D. design. It is about 20 feet in diameter, and supported about seven feet off the ground. I have an impression that it would be painted in silver (or aluminium ) paint, probably to produce a more vivid image from the projector.

I do not know when they started to be used, but I would suspect that World War 2 was the ideal time as they were badly needed to train hundreds of gunners in as short a time as possible!

The 1962 "Portabel" was a portable structure made out of proofed fabric that could be inflated to form the dome. Entrace was through an airlock with two sealed doors at each end of a short entry tunnel. A blower kept the whole thing inflated, and made up for any leaks.

The projector provided images of different planes flying under varying conditions, as well as realistic sound. The apparatus also created gun noise and images of clouds, to add realism.

[Les Freathy]

Two more nice photos of the 40mm Bofors on the MK1 carrage

Les

[alamotex]

Godwin I did a photo search of the Imperial War Museums On Line Collections www.iwmcollections.org.uk and found photograph number CH 18567 taken in December 1943 at the RAF station Leuchars which may have been inside a No.4 Dome Trainer. Does the sound and film projector in the foreground resemble any illustrations in your user manual for the No. 6 trainer? The gun certainly does not look like a 40 mm Bofors.

Brian

[Godwin Hampton]

Brian, I'm out of my depth here!

The gun, as you pointed out, is NOT a Bofors but two Browning aircraft machine guns on some sort of anti-aircraft mounting, probably for airfield defence. I would suspect that the guns are mounted staggered to allow the ammunition belts not to interfere with each other.

The sight is obviously common to both guns, and mounted between them.

The projector is similar, but naturally less modern. The 1962 one was fitted on a cabinet with wheels, much like a mechanic's tool chest. The one in the picture is projecting the image on to a mirror, and this would then be turned and tilted to make the image on the dome move. Thus speed could be altered, as well as the angle of flight. I would imagine that this was limited to half the dome, 90 degrees to the left and to the right of the projector, but this should not have been a problem since each anti-aircraft gun would usually have a limited arc of fire in action.

Hope this helps.

Godwin

[Les Freathy]

Some more Bofors images, Fyll you will like the first two a crowd gathers around a recent arrival in Greece, note the locals sprinkled with sailors
Les

2nd King George of Greece visits a RAF base anti aircraft defences

[Les Freathy]

Excercises in the UK in 1941, demonstration for the benefit of junior officers