Figure 1 - Bureau of Ordnance Dr. No. 389143.2

2

Page 3. paragraph 2:

Page 68(c) Paragraph 12(c), (Change 1):

Change sentence, "The torque applied to assemble the mechanism should be not less than 60 ft./lbs. nor more than 75 ft./lbs.", to read, "The torque applied to assemble the mechanism should be not Less than 40 ft./lbs., nor more than 50 ft./lbs."

Page 90:

3(a) The modified depth setting wrench, figure 1, was approved by OCL No. M23-43, for use with Depth Charge Release Tracks Mark 4, Mark 5, and Mark 7. This modification of the standard depth setting wrench (Dwg. No. 180379-10) was required in order to elimi-nate interference between the handle of the standard type wrench and the track struc-ture of these tracks, when making depth settings.

3(b) Aside from eliminating interference, the modified wrench has proved to be more con-venient to handle and use than the standard type wrench, having particular application where depth settings must be made through hand holes in track structure. Such hand holes have recently been added by Ordalt No. 2238 to the next to aftermost posts of Depth Charge Release Tracks Mark 3, Mark 3 Mod 1, and Mark 6 to permit access for depth setting on pistols attached to the second after most depth charges in these tracks. Therefore, vessels having these tracks installed for service use, will find it advan-tageous to have the standard depth setting wrenches, issued to them with the service tool sets, modified in accordance with figure 1.

3(c) The modifications required are such that vessels can readily modify the standard depth setting wrenches, or have the work performed by tenders, bases or Navy Yards. The Bureau of Ordnance will .not supply the modified depth setting wrench. Since the modification of the standard wrench, as noted herein, will eliminate the screw driver end, a separate tool will be required for making the deep settings on Pistols Mark 6 Mod 1 and Mark 6 Mod 2. In this respect the use of a medium size screw driver, as noted in Para-graph 3, will serve the purpose.