1928 Thompson Ordnance Drawing D35512
Posted 10 February 2020 - 07:20 PM
( I do engineering change notices ECNs at work that why I guess curious)
Posted 11 February 2020 - 08:45 PM
I don't have a copy of the 1941 initial release drawing but, as an engineer, my takeaway from looking over the drawings for a little while is:
The superscript number following the revision number in the revision table indicates the number of affected drawing items for that particular revision. For revision 1, that superscript number is 5. Accordingly, the revision symbol balloons on the drawing for rev. 1 are five in total, and point to (in no particular order):
- the original drawing number (D35512), which is crossed out, indicating that rev. 1 changed the drawing number from the 12/31/41 initial release document.
- the original drawing date (12/31/41), probably also referring to the change in drawing number from that of the original date of issue. Some of the other component drawings with revisions that changed their respective drawing numbers have rev. symbol balloons that point only to the original crossed out drawing number, and not the original drawing date, so indicating both the original number and date may have been up to the personal choice of whichever individual was processing that ECP/ECN/NOR that day.
- the section view through plane X-X, which deals with "qualifying of thread for ejector."
- some seemingly ambiguous point in space between sections G-G and B-B -- I don't know what change this might be indicating.
- at least one dimension for the receiver rails on section D-D, probably a minor change to nominal dimension or tolerance.
I thought at first that the annotation written above the 10/30/51 date for rev. 2 read 'cancelled', or 'correction', but looking over more of the drawings from the set available, this same revision note and date appears on just about every drawing, and on some is much more clearly/obviously printed as "conversion." That's an ambiguous note. Conversion to new drawing format? Conversion to 'archival' status? Without knowing Army Ordnance Department engineering drawing control policies/practices of the era, I can't really hazard a solid guess.
Edited by TehVice, 11 February 2020 - 08:47 PM.
Posted 12 February 2020 - 08:55 PM
Doug Richardson always claimed to have "all the original drawings".....Phil
Posted 13 February 2020 - 09:14 PM
Anyone else read the title and think "Cooling a Thompson drawing (raffle)"