Army Air Forces Statistical Digest,
World War II
Table 193 -- Twentieth Air Force -- B-29 Mining Operations: Aug 1944 to Aug 1945
Month Number of Missions New Fields Laid Airplanes Airborne Airplanes Mining Primary Fields Tons of Mines Expended a Tons of Mines on Primary Fields Airplanes Lost
  X X     B O M B E R     C O M M A N D
Total 8 7 175 155 540 485 -
1944              
Aug 1 1 14 8 12 8 -
1945              
Jan 2 2 76 66 233 197 -
Feb 1 1 12 10 36 27 -
Mar 4 3 73 71 259 253 -
  X X I     B O M B E R     C O M M A N D
Total 46 29 1,610 1,387 9,751 8,814 17
1945              
Mar 2 5 196 184 1,070 1,070 5
Apr 5 1 57 45 288 256 -
May 10 12 421 364 2,617 2,334 5
Jun 12 2 367 321 2,229 2,044 1
Jul 12 7 384 314 2,390 2,076 6
Aug 5 2 185 159 1,157 1,034 -

 a  Includes tonnage of jettisoned mines.