MLU FORUM  

Go Back   MLU FORUM > MILITARY VEHICLES > The Gun Park

Notices

Reply
 
Thread Tools Display Modes
  #361  
Old 21-09-18, 18:50
Richard Suggitt Richard Suggitt is offline
Registered User
 
Join Date: Aug 2018
Location: UK
Posts: 21
Default

Quote:
Originally Posted by notenoughtoys View Post
Scans sent - if you need any other details please let me know. Still looking for one more reference book (no luck yet) so I will email you if it ever shows up !
Hi ! We've been working on the material you kindly sent me, it's been very interesting ! Can I ask for another favour though ?

In the scan of the Finnish manual that has exploded diagrams of the corrector and sights on pages numbered 34 and 35, there are lines leading to a set of 'U' numbers... ie U1 to about U48. Is there a key where these 'U' numbers (presumably part or component numbers) are listed and described; if so, would it be possible to get a scan of that please ?

Thanks in anticipation
Richard
Reply With Quote
  #362  
Old 17-10-18, 16:10
Richard Suggitt Richard Suggitt is offline
Registered User
 
Join Date: Aug 2018
Location: UK
Posts: 21
Default

On another tack.... we've been looking at the electrical wiring that is on our Bofors. A lot of it is for lighting; this is run off a 6v battery and the wiring and connectors are all (naturally) low current. We can trace the wiring runs pretty well.

However..... there are some items we are not sure about. There are a couple of heavy-duty pin sockets just to the left of the ejection chute; one has a lead that goes into the centre of the revolve drum, and another lead that goes to a pretty chunky brass brass socket that is positioned just left of the ejection chute. All this is totally separate from the lighting wiring, and we have no idea what it is all for. It looks like you would plug a power supply into one part of this, and some device that needs power into the other; we have no idea why one lead goes into the revolve drum, as it is inacessible and has not electrical brushes on it. The gun is all manual.... no electric motors anywhere. I'll post some photos below. Any ideas anyone.... ?

Incidentally, from info in the Terry Gander book we now believe that 'our' gun was made in Poland in about 1942 (but to the 1938 design) and was shipped to Portugal.
Attached Thumbnails
Pic1.jpg   pic2.jpg   Pic3.jpg   Pic4.jpg   Pic5.jpg  

Reply With Quote
  #363  
Old 11-12-18, 18:21
Richard Suggitt Richard Suggitt is offline
Registered User
 
Join Date: Aug 2018
Location: UK
Posts: 21
Default

On another tack.... someone mentioned that the Corrector had a habit of turning as the gun traverses. Ours does the same.... we are now pretty sure we know why this happens, and that it is deliberate. If anyone is interested let me know, I'm happy to explain.
Reply With Quote
  #364  
Old 20-12-18, 15:09
Richard Suggitt Richard Suggitt is offline
Registered User
 
Join Date: Aug 2018
Location: UK
Posts: 21
Default

Another new question... we have to replace or retemper the set of balance springs that support the weight of the barrel when it is elevated. [They are housed in the two cylinders that sit below the barrel]. Unfortunately, we dont know how 'springy' the springs should be. I gather this is expressed in engineering terms as the 'spring rate' and is the weight required to compress the springs by one inch.

Does anyone have any technical info about the characteristics of these springs, especially the spring rate value ?
Reply With Quote
  #365  
Old 20-12-18, 17:14
rob love rob love is offline
carrier mech
 
Join Date: Feb 2003
Location: Shilo MB, the armpit of Canada
Posts: 6,364
Default

I can't say for sure in British gun terminology, but in North American terminology they are equilibrator springs. Basically you tension them until you have easy, almost balanced, elevation from level. Since there are two in this case, you will balance them left to right.

I was just involved in doing this with a M109 the other day, although they are equilibrated by hydraulic/nitrogen pressure.

If you need to know the length of new springs, I believe I have some at home, and there may even be one or two kicking around this museum.
Reply With Quote
  #366  
Old 21-12-18, 14:40
Richard Suggitt Richard Suggitt is offline
Registered User
 
Join Date: Aug 2018
Location: UK
Posts: 21
Default

Hi Rob, many thanks for your reply.

Unfortunately... the springs in our equilibriator are already adjusted to the maximum possible, and still dont balance the weight of the barrel. Hence they need to be retempered or remade... but we of course need to know the spring rate to temper or construct them to. Any chance you could place a known weight onto a spring (held vertically) and measure the displacement ? We could work out the rate from that.

As is the way of things I cant offer much by way of returning the favour.... though if your gun has the Bofors Speed and Course Sight fitted (as does ours) then I can share with you our discoveries about how it is used...

Thanks and best regards
Richard
Reply With Quote
  #367  
Old 16-03-19, 12:24
Richard Suggitt Richard Suggitt is offline
Registered User
 
Join Date: Aug 2018
Location: UK
Posts: 21
Default

General update about the Bofors at The Shuttleworth Collection in the UK. ....

.... after much huffing and puffing we successfully removed the six balance springs from the gun, discovering along the way that one was broken. Our friendly spring factory says that they cannot be retempered (as they cant tell what material they were made from or how they were made in the first place), and also says that they cant make new ones using rectangular-section strip. So... does anyone know of a source of unused balance springs, or has anyone successfully made replacement springs from round section strip ?
Reply With Quote
  #368  
Old 21-05-19, 21:20
JohnT JohnT is offline
Registered User
 
Join Date: Apr 2019
Location: Sweden
Posts: 2
Default Rob Fast's Bofors # 201

Quote:
Originally Posted by Rob Fast View Post
of Swedish made/ Finnish used Bofors guns. My Bofors is just that: M/38 1939 40ITK 38U, No. 201. Sweden. It is missing the big brass data plate, but this info is stamped onto the side of the breech. Any history on the gun? Thanks Rob
Im afraid I have to tell that Stelllan Bojerud passed away in 2015
https://en.wikipedia.org/wiki/Stellan_Bojerud

I had the benefit of talking with him about the Bofors guns many years ago and have continued my research in Swedish archives.

What I actually knows is that Sweden managed to get a contract for 68 guns from Hungary in spring of 1938.
Hungary needed Dollars to import other arms and thus expanded their licence production for export orders the years before the war. (as did Poland)

At the same time Bofors of Sweden produced more guns for export than for the small Swedish order with a Serial number range from 1 - 100.
Actually Swedish private donations accounted for more guns than the governmental orders in 1939.

This Hungarian contract was above and beyond the Swedish long term plan and budget.
But Swedish prime minister Hansson promised the Procurement agency they could count on new money for the next fiscal year, so they dared to sign the order.
The Swedish designation was 40mm Akan m/38 and at least in 1945,
the guns where branded as Bofors and not MAVAG.
Serial number range for those guns that remainded in Sweden Autumn 1939
where from 208 - 268.

On the other hand there where no planned organization for these guns
so the bottle neck on Swedish side was officers and trainers.
While we had enough Bofors guns to keep the trainers busy.
So a significant number of the new guns where stored waiting for a crew.

In 1937 Finland had started to set up their own licence production of Bofors 40mm at the state gun factory "VTT" but setting up a new factory took time and the optimistic plans where delayed numerous times.

A few months after the Swedes Finland also made an order in Hungary of 30 guns. These where to be delivered later and from Swedish experience the Finns wanted to start training as soon as possible.

Sweden passed over the first 8 guns to the Finns as a loan early 1939, and the Finns started training crews.
On the 23 September 1939 the first Hungarian guns from the Finnish order arrived in Sweden and instead of moving guns between the countries again.
Sweden took the new Finnish ordered guns with serial number 1 to 8 and
Finland kept the Swedish guns which I assume are numbered 201-208.

To confuse matters Sweden renamed gun number 1 to 8 to 201 to 208 in October 1940, So you have to look at the actual document from the period to make sense of it.

So in short - I feels pretty sure that your gun was bought by Sweden sent to Finland in spring 1939 and remained there until post war.

Kind Regards
/John T
Stockholm
Reply With Quote
  #369  
Old 21-05-19, 21:31
JohnT JohnT is offline
Registered User
 
Join Date: Apr 2019
Location: Sweden
Posts: 2
Default

Quote:
Originally Posted by m606paz View Post
One of the bofors finish!




Regards
Nice preservation!

Do you know if this one was one of the first six guns delivered during autumn of 1939 ?


Kind Regards
/John
Reply With Quote
  #370  
Old 22-05-19, 06:09
Tony Smith's Avatar
Tony Smith Tony Smith is offline
No1, Mk 2** (I'm back!)
 
Join Date: Feb 2003
Location: Lithgow, NSW, Australia
Posts: 4,454
Default

John, that is sad news regarding Stellan.

We communicated by email regarding Australian/Commonwealth Bofors guns and AA equipment, a conversation from which I'm sure we both benefitted from and enjoyed.

In post #59, Stellan was interested in this Carbon Arc searchlight:
Quote:
Originally Posted by Tony Smith View Post
The searchlight is an 18 inch model made by the General Arc Light Co, Long Island and is powered by an Onan 2 cyl 40 volt, 50 amp (2Kva) generator. The reflector is polished aluminium. Rotation and elevation is hand controlled, but carbon rod feed to maintain the Arc is automatic
This is a small light by AA standards, but quite effective. It was recently illuminated from a lookout over town for the 100th Anniversary of Armistice Day in November. The photos below were taken from the town below the lookout, over 4Km away!

While it was lit to commemorate Armistice Day, the next opportunity we will salute Stellan too!
Attached Thumbnails
DSC03460-1.jpg   DSC03491-1.jpg   DSC03493-1.jpg  
__________________
You can help Keep Mapleleafup Up! See Here how you can help, and why you should!
Reply With Quote
  #371  
Old 18-03-20, 18:11
Hanno Spoelstra's Avatar
Hanno Spoelstra Hanno Spoelstra is offline
MLU Administrator
 
Join Date: Feb 2003
Location: The Netherlands
Posts: 11,553
Default 1-ton 2 wheel GS trailer, popularly know as the "Ben Hur" trailer

Quote:
Originally Posted by Hanno Spoelstra View Post
The F60B in the top picture is towing a 1-ton 2 wheel GS trailer, popularly know as the "Ben Hur" trailer after the Ben Hur Mfg Co. They were also built by American Trailer, Bantam, Checker Cab Mfg Co and various other manufacturers - apparently Willys as well (ref. Richard's note).
This question came up on another forum, so also sharing info from David Hayward's book on Pearson's of Liverpool here.

Click image for larger version

Name:	IMG_4692_cropped.jpg
Views:	0
Size:	968.2 KB
ID:	112557 Click image for larger version

Name:	F60B.JPG
Views:	0
Size:	130.3 KB
ID:	112556

This text is not entirely correct: 1-ton trailers were not used with Jeeps, nor was the "F60B converted to SP units and the trailers re-allocated for further use" - the F60B was a SP unit from the onset.

Click image for larger version

Name:	IMG_4693.jpg
Views:	0
Size:	315.2 KB
ID:	112555
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +2. The time now is 14:58.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Copyright © Maple Leaf Up, 2003-2016