Hi,

We probably all know lists like this one and we also know that they are not very accurate but how inaccurate are they really.

1939 # 101 - 9719
1940 # 9720 - 27039
1941 # 27040 - 50549
1942 # 50550 - 70000
1943 # 70001 - 90000
1944 # 90001 - 110000
1945 # 110001 - on

Now we have access to the BSA factory ledgers we know for sure that up to WM20 69699 there are inconsistencies in the list. But how about this list for the later years we don't have any factory information for.

I would like to get the frame number list on the website as accurate as possible and I have the feeling that not all later war dating is correct.

Henk

email (option): ahum@quicknet.nl

Hi Henk

It may be best to look at them by contract because I think the contracts overlapped.

One of my M20s has the frame number WM20 13142 and that didn't leave the factory until 1942.

Rob

email (option): robmiller11(a)yahoo.co.uk

Henk, up until the end of 1942, the Chilwell records show daily arrivals so some calculations can be made. I assume that you have the start number for 1942 ? Is 50550 taken from the ledgers ?

They used an odd system, I think based on six working days per week...contract C13290 commenced at 71818 on day 322 of 1942 and by adding together the daily acceptances, I arrive at WM20 73481 before the first 1943 deliveries. These will be a few days out as they were sent by train to Chilwell I believe.

I think that you can safely alter 1942 to 50550 - 73480 but after this it's guesswork as the planned delivery dates don't fit in with each other.

However, they do seem to have been able to produce 2000 per month if necessary and if materials were available.

This list comes from a guy in Australia so the 50550 isn't necessarily taken from the ledgers, not by me as least.

I'll get in to what you and Rob mention and alter the list where I can. New dating certificates available of course when necessary.

Thanks for your input, keep it coming if possible.

Henk

email (option): ahum@quicknet.nl

I have made a few mchanges to the frame number page. Here a new list with the best I can do with dating a BSA WM20.



Especially during the first war years frame numbers got very mixed up and very early frames could leave the factory much later then you would expect.

Up to WM20 69699 the exact day a BSA left the factory is usually available. After that frame number it's an educated guess made with the help of Rob and Rik. I would love to be proven wrong and I'll be happy to make more changes to the list to improve it.

Henk

email (option): ahum@quicknet.nl