40 mm Bofors AA guns made in GB and US

[Hanno Spoelstra]

Stellan, in case you are looking for US references, TM9-252 is available on CD-ROM - see a review here.

And have you read WWII Tech Pubs Briefing 40-mm L/60 Bofors Anti-Aircraft Gun

H.

[Stellan Bojerud (RIP)]

Thanks Bill for the Sperry pictures. Such listening equipment were still used in early WW 2.

Hanno, the Tech Pub I had seen before. There are a few minor errors. The US Ref i had not seen. Thanks!

Enclosed: Australian Dummy Bofors.

[Hanno Spoelstra]

Originally posted by Stellan Bojerud
Enclosed: Australian Dummy Bofors.

Or: Dummy Australian Bofors?

[Bill Murray]

Or, Bofors by Dummy Australians.
This could go on for ever bloody ever.
And...Australians have always been my best mates so the post is in jest.
Bill

[Stellan Bojerud (RIP)]

Bofors gun operated by Katanga gendarmes. Elisabethville December 1961. British MK III or Canadian MK C 1 gun.

[Stellan Bojerud (RIP)]

Gun in UK home defence. 1943 type sights.

[Stellan Bojerud (RIP)]

Canadian AA units in GB summer 1941

HQ Drury Lodge
CO: LtCol G.A. McCarter, RCA

Trps: Colchester (Sobraon Bks and Goojerat Bks)

1st LAA Regt CO: LtCol W.E. Huckvale
35th Bty Sherbroke
89th Bty Woodstock
109th Bty Trail

Regt and Btys formed in GB

2nd LAA Regt CO: LtColE.W. Neville
2nd (ex-1st) Yorktown
4th Kingston (Permanent Force)
5th Montreal
54th Brantford

The first Regt that got to GB. 2nd Bty depoloyed under GB Command at Hartlip, Thames Estuary and 4th at Kerington Manor, S:t Mary´s, Kent. 54th Bty formed in GB.

3rd LAA Regt CO: LtCol B.R. Ker
15th Bty Winnipeg
16th Bty Vancouver
17th Bty Calgary
53rd Bty Toronto, formed in GB

From Canada in Feb 1941.

4th LAA Regt should arrive later.

Bty HQ and 3 Troops each of 4 guns. 8 Offrs and 273 ORs.

Guns
2nd Bty 12
4th Bty 12
Other Btys Nil. They were trained by using totally 8 guns MK III ob MK II platforms. In May 1941 increased to 12 guns.

Who has more on Canadian AA during WW 2?

Picture: MK III on MK II carriage.

[Godwin Hampton]

Stellan,as far as I know,

The Kerrison Predictor could work only with the Mountings Mk 1 and Mk111. The Mk1 was fitted with elevation and bearing receiver gears, which indicated to the layers where to point the gun by making a dial and a pointer coincide. This was the only way of "aiming" the gun, as no sights were fitted.
The Mk111 was the only mark fitted with the "Oil Units". The 2 layers ( for traverse and elevation) would unclutch their hand levers and dismount, leaving only the loader on the mounting. The Predictor would then control the gun via a cable plugged into a socket on the platform. This was connected to the oil units through a 15 way slip ring at the turntable. Data was fed into the predictor regarding the chosen target, giving bearing, speed, height, and angle of flight (horizontal or diving/climbing.)

The Predictor would work out a Future Position where hopefully the shell would meet the target, and worked the oil units so that the gun turned and elevated on its own to face the Future Position.

The gun was then fired by the loader using his foot pedal. Power to make the motors in the oil units turn was provided by a 2.75 Kw petrol engine driven generator, so this was also necessary in SP mountings. I suppose it would be carried in the Predictor vehicle.

All this became obsolete ( and simpler and cheaper) with the introduction of the Stiffkey Sight. On this the corrections were applied mechanically directly on to the layer's sights. The Sight Correction Number would control a handlebar with 2 motorcycle-type levers at its' ends. He would tilt the bar to match the angle of flight of the target, and would 'click' one of the levers a number of times,depending on his estimate of the target speed. After the engagement, the correction would be returned to Zero.
Thus many of the Mk111 mountings retrofitted with or produced with the Mk5 Correctional Sight are without the oil units.

[Stellan Bojerud (RIP)]

I agree. Here is a photo of the Kerrison predictor.

[Stellan Bojerud (RIP)]

Kerrision predictors were also made in USA by Singer Corp. Sight computing M 5. Here an Australian one.

[Stellan Bojerud (RIP)]

A Finnish Bofors.

[Godwin Hampton]

Stellan,

I was just looking back through this thread at the picture of a radar controlled Mk 111 mounting on Mk 1 platform. The loader is the only one on board. The writing painted on to the gun shield is the list of lubricants and their colour code. Each grease nipple or filling plug would have a coloured ring painted around it to denote the lubricant to be applied.

The Mk3 platform was the Mk2 without the rope-operated hydraulic brakes but instead had front wheel mechanical overrun brakes, cable operated. This simplified removing the axles as the connection to the platform was now removed.It also simplified maintenance and repair. The brakes were automatic now, so none of the crew needed to sit at the back of the tractor to apply the brakes when necessary.

[Godwin Hampton]

Originally posted by Stellan Bojerud
Now I have learned that a Polish made carriage has wheels with eight holes and six bolts (is that the correct expression?). A Swedish made has also wheels with eight holes but only five bolts. The Hungarian made guns I am not sure of yet.

Thus this could be a Polish made gun.

I would prefer "wheels with eight spokes......."

[Godwin Hampton]

Originally posted by Stellan Bojerud
Who is he? Not the man in bowler hat but the officer standing to the left (on the picture right) to the Prime Minister?

Gen Sir Frederic Pile, GOC British AA Defence?

The officer left in forage cap. Which unit had such multi-colour caps?

The wheels has six bolts wich suggest that this is a Polish-made Mk I gun or possibly an early made British Mk I.

Stellan, look at the photo:

The bombardier ( corporal to you infantry guys ) has pulled the quick traverse lever back and has been or will be traversing the gun by pulling it round onto another target. The lever, when raised, disengages the drive to allow the mounting to be swung round.

When using the predictor, this method could be used to align the gun with the predictor. An indicator would show which way to turn and when they were aligned and the lever was then folded down again to re-engage the drive

[sapper740]

While still a reservist in 2000 I had an opportunity to go on board one of the new small Coastal Patrol vessels at the Naval base in Esquimalt, B.C. It's main deck gun was a 40 mm Bofors so I guess these old guns are still soldiering on in Canadian service. Anybody who has recently served in the Canadian Armed Forces can tell you stories about old equipment! When getting flown about in Hercs it was always a perverse interest of mine to find out which was older....the pilot or the plane! No need to answer which was the oldest! An friend of mine in Fort Worth works for Lockheed and he tells me that the Lockheed engineers are very interested in the Canadian Hercs as they are the highest time C-130s in service with a military anywhere! Perhaps its got something to do with corrosion around the piss tubes!

Cheemo!

[Stellan Bojerud (RIP)]

Originally posted by Bill Murray
More misc stuff that some times comes up here. Sorry, Norwegian Bofors.

Bill!

That photo shows one of the 10 privatly owned Norwegian Bofors guns. They were bought by A/S Norsk Hydro in Rjukan (yes the heavy water plant - "Heroes of Telemark") from Bofors in 1939.

Photo: The Norwegian Army had an AA Bn in Germany during some years post WW 2. This Bn had 12 x MK 1 and 7 x MK 3 (Of which one in reserve).

[Stellan Bojerud (RIP)]

Thanks Godwin,

Here you have a WW 2 version of "Malta by night".

[Murray]

I couldn't resist adding this picture to the thread.
2nd LAA (Yorkton) Bty, 2nd LAA Regiment -Holland 1945

[Murray]

And another

[Godwin Hampton]

Murray, we're lucky you couldn't resist!

The bofors seems to be USA manufactured, with the Mk 1 welded platform and with the characteristic american combat wheels, but with all the british mods, like the shields and the Stiffkey sight.

[Stellan Bojerud (RIP)]

Hmm? The British Mk 1 (riveted) platform or carriage was copied in USA and designed M 1. Most of these issued as lend-lease to other countries.

The welded version of the British Mk 1 carriage developed in USA was known as M 2 and in a later version M 2 A1.

Photo: US 40 mm AA gun M 1 on carriage M 2.

[kevinT]

I know this is post war but sort of related.
I was going through some of my late Fathers old books etc the other day and came across
Gun Drill, for Gun-Equipment 40/70 L3 (land service) when used at hand or local power control. 1964.
Also
User Handbook
Truck, 3ton, GS, Cargo, 4x4, Bedford-R
Truck, 3ton, GS, Cargo, with winch, 4x4, Bedford-RLW
Chassis, 3ton,GS, Recovery, Light, Bedford-RLC
Issued Jan 1958
W.O. Code No. 18374

He was in the Royal Artillery, 1947-1973
Of any interest to anybody?
Cheers
Kevin T

[Crewman]

Hello Stellan!

Originally posted by Stellan Bojerud
A number of states aquired rights for licence production. Austria (Staatsfabrik) 1935, Belgium (Fabrique Nationale) 1936, Czechoslovakia (Skoda) 1938, Finland (State factory) 1937, France 1937, Great Britain 1937, Hungary (Mavag) 1935, Norway (Kongsberg) 1937, Poland (Starachowice) 1935.

Full name of the Polish Starachowice-based manufacturer is: Starachowickie Zak³ady Górnicze SA.

Originally posted by Stellan Bojerud
I know that 406 guns were made in Poland of which 168 were exported to Great Britain, Netherlands and Rumania, but I do not know how many guns to each nation.

The figures of these Bofors guns are the problem in Poland as well. According to various Polish data:

78 guns – ordered by the Polish Government in Sweden
414 guns – manufactured in Poland
168 guns – exported by Poland
358 guns – the number of guns that served in the Polish Army in September 1939


Sources:

Adolf Stachula
Dylematy polskiej artylerii przeciwlotniczej okresu miêdzywojennego
(The Dilemmas of the Polish Anti-Aircraft Artillery of Inter-War Period)
Przegl¹d Wojsk Lotniczych i Obrony Powietrznej
(The Air Force and Air Defense Review)
Poznañ, September 2002

Piotr Rozwadowski
Polskie armaty przeciwlotnicze 75 mm wz. 36/37 oraz 40 mm Bofors
(Polish 75mm and 40mm Anti-Aircraft Guns Models 36/37 and Bofors)
Dom Wydawniczy Bellona, Warsaw 1998
ISBN 83-11-08906-X

Marek J. Aszyk
Uzbrojenie Wojska II Rzeczpospolitej. Armata przeciwlotnicza kal. 40 mm wz. 36
(Armament of the 2nd Republic. Bofors 40mm Anti-Aircraft Gun Model 36)
http://www.wojsko18-39.internetdsl.p...ien/opl40.html



Polish Bofors 40mm guns wreckage pictorial after 1939 Campaign

[Crewman]

One more US specimen. Photo taken in 1943.


Library of Congress LC-USW33-000888-C

[Godwin Hampton]

Crewman,

Very interesting, and at the same time very sad pictures of the Polish Bofors guns. They seem to tell us though that they went down fighting! Another thing that struck me is that all the wheels have been removed.......sabotage?

[Crewman]

Originally posted by Godwin Hampton
Crewman,

Very interesting, and at the same time very sad pictures of the Polish Bofors guns. They seem to tell us though that they went down fighting! Another thing that struck me is that all the wheels have been removed.......sabotage?

Hello Godwin,

Hard to say if sabotage...

According to my knowledge all types of wheels are desired and valuable "war goods" for civilian people all over the world, always and at every war.

If sabotage then rather Polish troops sabotage against the Germans. I think that majority of the guns showed at the pics has its vital parts destroyed by Polish troops to make the guns unuseful for the enemy.

Best regards

C.

[Godwin Hampton]

Crewman,

The only one showing wheels in the background has had them removed complete with the axles. This could not be done with the original Swedish platform! Is this a Polish design? It seems to have 3 arms and levelling jacks, rather than the usual 4.

The Bofors with the barrel facing the camera and with the small shed behind also seems to have this type of platform. I have never seen this before today. Thanks for sharing them with us.

[Crewman]

Originally posted by Godwin Hampton
Crewman,

The only one showing wheels in the background has had them removed complete with the axles. This could not be done with the original Swedish platform! Is this a Polish design? It seems to have 3 arms and levelling jacks, rather than the usual 4.

The gun seems to have Polish camouflage and the pic comes from German soldier album of 1939 so I think it must be Polish-made. Unfortunately I do not know how much the Poles re-designed the original Swedish platform because I do not have all possible Polish articles about this guns so I am not top expert in this field. What I may write the Polish platforms had the Lockheed-type brakes and the Ackerman-system axles but I am not sure if it is something other than in the original design because I am unable to compare it with the Swedish materials on the subject of 40mm Bofors guns.

Originally posted by Godwin Hampton
The Bofors with the barrel facing the camera and with the small shed behind also seems to have this type of platform. I have never seen this before today. Thanks for sharing them with us.

All pics are "by Wehrmacht of 1939 Campaign" so I think the guns must be Polish-made. No doubt there were two types of the wheels in Polish Bofors because two types can be seen at the Polish photographs. I will try to post more Polish Boforses (normal, undestroyed) if I find copyright-free pics.

Best regards

C.

[Godwin Hampton]

The Ackermann steering and the Lockheed brakes were fitted to the original design. In fact the reason the axles could not be made removable was because the brake master cylinder / reservoir was inside the rear longitudinal girder, with the wheel brake cylinders at the rear wheels. Flexible brake hoses allowed the axle to rotate and thus lower the mounting onto the jacks. To remove the axle would mean having to remove the flex hose, and this would allow fluid out and air in, and necessitate bleeding the system after reconnecting!

The British Mk.2 Platform had the master cylinder / reservoir fitted directly to the rear axle, so this could be removed without disturbing the braking system.

[Crewman]

Originally posted by Godwin Hampton
The British Mk.2 Platform had the master cylinder / reservoir fitted directly to the rear axle, so this could be removed without disturbing the braking system.

Sometimes the number of Polish Boforses exported to the UK is mentioned as 150 pcs, other time as 168 pcs. Maybe 16 pcs were not exported in fact and they stayed in Poland but I do not know if they were equipped with the wheel system you described...?


Polish-built 40mm Boforses