40 mm Bofors AA guns made in GB and US

[Godwin Hampton]

Crewman,

The British wheel system I described was for the totally different Mk II platform designed by the engineers at Nuffield Mechanisations to be much simpler than the original swedish design. It can be seen in many of Stellan's photos and can be easily identified by the baloon tyres and the tubular outriggers.

One of the guns shown in your latest set of photos is actually a Russian copy of the Bofors. See Stellan's colour photo at the top of the previous page.

Sorry to have confused you about the wheels/brakes...

[Woj]

Originally posted by Crewman
[B]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...?

Marek Piotr Deszczynski, Wojciech Mazur, "Na krawedzi ryzyka. Eksport polskiego sprzetu wojskowego w okresie miêdzywojennym" ("On the Brink of Risk. Export of the Polish Military Equipment in the Interwar Period"), Warszawa 2004. Polish text with Summary in English.
This book you can find (for example) here: http://www.neriton.apnet.pl/product_...roducts_id=272 or here: http://www.lideria.pl/sklep/opis?nr=56177 or here: http://www.historyton.pl/catalog/pro...oducts_id=1511

Woj

[Crewman]

Woj,

Thank you! Writing the posts I did not know this new book. You know that Polish bookstores with the military history books are pressed down by the tons of Western books and sometimes it is hard to find something new in Polish.

Unfortunately the subject of the AA artillery is underestimated by our publishing houses and, to some extent, also by the authors that is why sometimes there is a space for speculation. The same goes for various technical aspects of the Polish Bofors 40mm guns. It would be hard to tell that small booklet I mentioned (ISBN 83-11-08906-X) is a kind of very good monograph of the Polish-built Bofors AA guns.

Thanks and best regards

C.

[Woj]

Originally posted by Crewman
Woj,

Unfortunately the subject of the AA artillery is underestimated by our publishing houses and, to some extent, also by the authors that is why sometimes there is a space for speculation. The same goes for various technical aspects of the Polish Bofors 40mm guns. It would be hard to tell that small booklet I mentioned (ISBN 83-11-08906-X) is a kind of very good monograph of the Polish-built Bofors AA guns.

Thanks and best regards

C.

Sure - new research would be needed. During last some years I found some important sources in the Polish archives. I hope that I will be able to clear some interesting issues soon (till end of this year?)

Best regards,

Woj

[Murray]

I posted some pictures to this thread last month of the 2nd Yorkton LAA Bty, 2nd LAA Regiment in Holland in 1945. The picture attached to this post is B Troop of the same Battery at Detling Airdrome in Surrey, England 1941. According to the Battery's diary, they were at Detling from April to July 1941. The equipment according to the Diary was "semi-mobile Bofors with No.3 Predictors, 4 to a Troop."

[sapper740]

I know this thread is about towed Bofors, but since we're all such great fans of the gun, I thought you'd like to see some pics I took last week aboard the U.S.S. Texas (BB35)

[sapper740]

Originally posted by sapper740
I know this thread is about towed Bofors, but since we're all such great fans of the gun, I thought you'd like to see some pics I took last week aboard the U.S.S. Texas (BB35)

[sapper740]

Originally posted by sapper740

[Godwin Hampton]

Originally posted by Stellan Bojerud
Thank you for the M 19 Bill!

This is the British version of the airborne Bofors gun. The Canadian version you can see on top of page 1 of this thread.

The Canadian version was called "Bantam" carriage. Was Bantam the producer?

What were those guns and carriages called officialy? Mk ??

Answer;

ORDNANCE, Q.F. 40-MM., MARK 1/2 on
MOUNTINGS, 40-MM. A.A., MARKS 9 AND 10 and
PLATFORM, 2-WHEELED, 40-MM. A.A., MARK 1

The Ordnance was the standard Mk 1* gun fitted with a muzzle brake to preserve stability during firing because of the lighter mounting and platform.

The Mk 9 mounting is a modified Mk 3, while the Mk 10 is a modified Mk 4. The frame, platform and seats were removed and replaced by others of different design. The electrical gear and the shields were also removed.

The Mk 1 platform was a new design, having 3 girders ( or outriggers ). Two were swung together to form the towing bar, while the third slides in and out of the platform.

Brakes were Warner electric, as used on other British heavy artillery pieces.

[Phil Waterman]

This winter I picked up a 3 phase generator which was designed to go with the US or UK version of the 40MM it was used to feed the fire control system and is set up for 3 phase at 50 or 60 cycles. The manual explains the power settings for the British fire control system.

[Godwin Hampton]

The Britsh produced a particular generating set for the Bofors and Predictor. This consisted of a Coventry Climax 4 cylinder side-valve engine of 847cc capacity belt-driving a Crompton Parkinson 3-phase alternator. Output was 2.75 KVA ( 130 volts, 12.2 amps ) at 3000 rpm. Frequency was 50 cycles per second.

I have the remains of two such sets, from which one can hopefully be assembled in the future.

If your generator is this type, I have the Field Manual, which only covers the set,though.

Could I be so cheeky as to ask for a photocopy of your Manual, as mine gives no details of the actual Fire Control. I will naturally cover any expenses incurred.

[Phil Waterman]

I plan to scan the manual in to a pdf file so it will be no problem to send it to you. The manual is for generator so it is just talking about the use and how to set it for the different voltages and cycle rate.

[Godwin Hampton]

Very nice of you, Phil! Thanks.

[Phil Waterman]

Originally posted by Phil Waterman
I plan to scan the manual in to a pdf file so it will be no problem to send it to you. The manual is for generator so it is just talking about the use and how to set it for the different voltages and cycle rate.

Here is the link to M5 Generator Manual sorry for the large file size I'll work on keeping it readable and making it smaller.

http://www.canadianmilitarypattern.com/ to my site
http://www.canadianmilitarypattern.com/Generator.htm directly to the Generator Page

[David_Hayward (RIP)]

In Britain the Bofors was produced in the main, by Nuffield Mechanisations, (part of Morris Motors). Their first one being delivered to the army from their Coventry factory on 15th June 1939.

'On 7th January 1939, Colonel NO Carr wrote to the DCE & ME, Department of National Defence, in respect of the body for a Field Artillery Tractor, No1, Mk I, for towing the QF 40-mm AA Equipment. He requested an order be placed with the British War Department for the supply of a copy of the General Arrangement Drawing, Design Drawing DD(V)630, together with photographs, of the tractor body as referred to in the R.A.C. Minutes A-7320 of 12th October 1938 and A-7349 of 9th November 1938'.

So far as I can see this body was the Morris-Commercial body as fitted to the CDSW, which of course went into production by Wolseley Motors initially in 1939 and then Austin Motors the following year.

[David_Hayward (RIP)]

Has anyone got a photo of a CDSW Bofors tractor please?

[Tony Smith]

Sort of off thread, but.....

If a Bofors gun is fitted in an AC130 gunship, should it still be called an AA gun? If not, what then? Pro-Aircraft? Anti-Ground?

[David_Hayward (RIP)]

Anti-Ground?

.. or 'Anti-anything'?

[Bill Murray]

Anti Social.
Bill

[sapper740]

Originally posted by David_Hayward
.. or 'Anti-anything'?

It would still be known as A.A.......Anti Arsehole!

[nuyt]

found by Lorenzo Tonioli of Italy:
http://cgi.ebay.com/ws/eBayISAPI.dll...sPageName=WDVW
What type of 40mm Bofors?

[Godwin Hampton]

Lorenzo,

The gun seems to be an original Swedish 1936 Model. You may have noticed that there is no apparent sighting system, but this could mean that the Gun is controlled by a Predictor. This would work out where the Gun should be pointed to the 'future position' of the aircraft to hit it. This position would vary with Speed, Direction, Altitude, and Angle of Flight of the target.

The Predictor would move pointers on dials in front of the layers (not visible in the photo) and the layers would elevate and traverse the gun to match the pointers, without looking at the target. When the pointers were matched, the Gun would be fired.

[Mats]

Eric and Godwin

I agree that it's a gun of the original pattern, known in Sweden as the model 1936. A lot of small details gives it away.

[nuyt]

no text

[Stellan Bojerud (RIP)]

The Bofors guns sold from Sweden to the Netherlands i think were m/35.

NL had no predictors.

The gun has normal "Polish sights" but they are hidden behind the guncrew. The man to the right is looking into the sight. Left gun trainer is hidden behind the standing loader in his greatcoat.

[Godwin Hampton]

Stellan, you are absolutely right!

Now that you have pointed it out, I realised that there are 3 seats, and the one nearest the camera is the sight correction number, bent over the BOFORS COURSE AND SPEED SIGHT corrector ( in British Army terms). I suppose the man standing next to him is the Gun Commander,giving him the data about the target to feed into the corrector.
The loader is obscuring the sight, but the cable to the graticule illuminating bulb remains visible.

The apparent absence of the rather bulky sight cross tube mystifies me! Could it have been 'censored out' of the picture?

[Stellan Bojerud (RIP)]

The NL guns should have the m/35 FC (picture).

[Godwin Hampton]

Originally posted by Stellan Bojerud
The NL guns should have the m/35 FC (picture).

.......also known as the Course and Speed Sight.
This was/is a very ingenious piece of equipment. It is fairly complex, and must have been pretty expensive in those days.

It can be described as an on-board predictor, and from the data fed into it, it mechanically turned both sights left or right, as well as tilting the sight bar to incline the sights up or down. This so that the layers would keep the sights centered on the target while the barrel would be delivering the shells to the 'future position' of the aircraft.

Data would be inputted by turning the two handwheels, one to set the predictor to the range to the target, and the other to set to the aircraft speed. The pointer on the arc was for setting the angle of dive.

Maybe Rob Fast would be so kind as to post some pictures giving us more details of this intriguing piece of equipment......

[Rob Fast]

photo as requested

[Godwin Hampton]

Rob,

Those pictures are better than a year's supply of Playboy!

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?

NOW the Forum is REALLY becoming interesting! ( Not that it wasn't, mind you, but this is something I always wanted to get to the bottom of, but never found the opportunity.)