THOMPSON DRAWINGS

[Doug Richardson]

posted by mkw

 

Drawings

 

In response to the recent subject of why Numrich could not get the dimensions right on their guns, someone made the statement that he could not understand why because the "drawings were readily available". Let me comment about that.

 

I made my first steel Thompson receiver in 1957 from drawings I made by reverse engineering the gun because I could not find any original drawings. I contiued reverse engineering the gun and searching for original drawings. We used the drawings I made to manufacture the 1/2 scale Thompson guns that were featured in a number of gun magazines. I continued spending a lot of time and money trying to find original drawings. My efforts finally paid off in the mid 1980s when I hit the "mother load of drawings". I then had most of the drawings. Again during the late 1990s, I located the missing drawings. So, it wasn't until about year 2000 that I had all the drawings. Some of the drawings were stolen from me and appeared on the internet. But every original Thompson "readily available" drawing came from me as far as I know. I have every drawing for every part of every model Thompson gun with the exception of the Models 1922, 1923 and 1927 and some prototype models. I also have the drawings for most of the accessories. Tracy Hill did uncover some early versions of some of the drawings. After what I went through to aquire the drawings, I did get a bit of a chuckle over the assumpton that the drawings were "readily available" in the 1950s. If Numrich had any drawings, they must not have known it.

[dalbert]

There is a drawing of the Thompson Model "F" of 1922 in TUTB, but no "Model of 1922" Thompson has ever been substantiated.

 

David Albert

dalbert@sturmgewehr.com

[reconbob]

In or around 1978 I obtained from the government via the Freedom of Information Act original

U.S. Ordnance drawings for the Thompson submachine gun. All of the drawings for the Thompson and all other

guns were archived by the government. I only requested the drawings I wanted such as receivers,

barrels, and trigger frames as well as many other parts, but I did not request everything. The

drawings were on the old IBM cards with a microfiche window which you could get printed drawings from.

I do not know if it would be possible to get prints from such a format today.

Now, this was only 3 or 4 years after the semi-auto came out so its likely that if Numrich knew about

the FOIA, who, where, and how to ask he also could have obtained original drawings as well.

This is interesting because the drawings I have from 1978 - U.S. government microfilm of U.S.

Ordnance drawings - are not what Doug refers to as the "mother load". The drawings he found must

be actual paper sheets of drawings found/leftover from the old days....

 

Bob

Edited August 30, 2014 by reconbob

[TD.]

Interesting comments by Doug. Of course, it is just his supposition that Numrich Arms did not have the original AOC drawings for the Thompson submachine gun and accessories like the C drum. What I can believe is Numrich Arms would not share this propriety information with someone that wanted to make receivers. That they did a lousy job in manufacturing this wonderful piece of equipment is not in issue.

[Doug Richardson]

posted by mkw

 

 

I was unaware that Bob Bower had gotten some drawings from an FOIA request. That probably makes him the first, last and only person to accomplish that feat. But like he said, microfiche never blows back up with the original detail. That is why I have steamer trunks full of hundreds of full size drawings. I tried to make them available to everyone but I had to give up because of the time involved. People did not understand that a simple request for the pivot plate drawing, for example, means a drawing for the trigger axis, another for the sear access, another for the plate, anorher for the assembly and another for the material, heat treatment and finish.

 

As far as the Model of 1922 TSMG is concerned, one which I discovered, inspected, took apart and photographed belongs to the French Government. Another belongs to the Russian Government and was inspected and photographed for me by my friend, Tom Nelson. A third one belongs to the Danish Government and was inspected and photographed by a friend. A fourth one is at West Point but it has been so modified as to be useless. It was undoubtedly used to develop the Model of 1923. Then there is a vintage photograph of George Goll demonstrating the gun to what appears to be foreign dignitataries. It seems that the model was developed to sell to foreign militaries and probably rejected because it had no provision for a bayonet. Since I discovered this gun and documented it (See my book "MODELS".), I felt that I had a right to name it. But, obviously, the only reasonable conclusion is that it doesn't exist.

 

Regarding the Model of 1923, the evidence is that only one was made, never sold and finally broken up for parts.

Edited September 1, 2014 by Doug Richardson

[dalbert]

Doug,

 

Yes, I have your book on models, and yes, the only reasonable conclusion is that the Model of 1922 doesn't exist. If it did exist, it would most likely be a skeleton stocked Thompson with a tubular receiver. (The Model "F" of 1922, as shown in the drawing on page 821 of TUTB)

 

The Model F is the only Thompson SMG design for which we have documentary evidence dating to 1922. It probably didn't go beyond the drawing board because more than likely, it didn't incorporate the Blish principle. A Model of 1922 was also not mentioned by Eickhoff, Payne, or Goll in any of their correspondence or interactions with Helmer during his research for TGTMTTR in the 1960's. The TSMG's you mentioned are either referred to as the Military Model, or the Model of 1923 in the Helmer correspondence.

 

David Albert

dalbert@sturmgewehr.com

[reconbob]

Doug is right about enlarging the microfiche. A large drawing such as a Thompson receiver, and many

others such as the trigger frame and barrel were D size drawings. This is a drawing 24" x 36" with the entire

area of the sheet used except for a border of perhaps 1". When they photographed the drawings for the

purpose of microfilm they must have placed them in a standard template based on the size of the drawing.

When the microfiche gets printed the 24" x 36" drawing is rendered into a rectangle that is now approx.

12" x 19 1/2" - in other words, its shrunk down about 50%. Here is the drawing we use on the shop floor

that was printed over 25 years ago from the microfilm. Please excuse the dirt, stains, etc.

 

http://i51.photobucket.com/albums/f392/reconbob/IMG_5317_zps1d3a42ec.jpg

 

Here is the title block of the same drawing. Note that it appears the drawings were archived in 1957,

the date of the drawing is December 31, 1941 (they were working on New Years Eve?) and that they

reference drawing "AOC -45-1-2" what ever that is.

 

http://i51.photobucket.com/albums/f392/reconbob/IMG_5318_zps2cbe5a01.jpg

 

Fortunately you can figure out all of the data and dimensions on this one with a magnifying glass. The

same is not true of very detailed drawings such as the M1918A2 BAR. I also have these drawings on microfiche

and when you shrink the BAR down 50% some of the areas become hopelessly blurred where the lines and

dimensions run together.

 

I recently was able to get some Grease Gun drawings from the government via an FOIA request. Now, at least

based on these Grease Gun drawings, it seems that many thousands of old drawings have been scanned and

saved in a variety of digital formats. The search and delivery of the drawings takes only a couple of minutes as

it would with any computer database. The drawings are sent via email - I requested pdf format which you can

zoom for printing and you get absolutely perfect copies - even better because you can zoom and print bigger than

the original sizey and everything is crystal clear....

 

 

Bob

 

[buzz]

When Numrich acquired the remains of the AO corporation (or however you choose to refer to the transaction), they did not get the drawings for the gun?

 

You would think that a factory that made millions of thompsons would have had multiple copies floating around to be crated up with the rest of the debris.

 

I work in engineering, in my industry nothing ever gets built without detailed drawings. If you took the drawings away we would have to stop all work.

Edited September 1, 2014 by buzz

[Mk VII]

45-1-2 appears to be AOC's drawing number for the receiver. 45-1-1 was 'Barrel', 45-1-3 was 'Lock', 45-1-6 was 'Sear', 45-1-7 was 'Magazine Catch Assembly'.