COMPARATIVE VALUE OF TARGETS
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REQUIREMENTS FOR AIR ASCENDANCY Tab B Japanese Theatre - Appendix J-III Naval and Commercial Bases |
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NAVY YARDS |
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No. |
Name and Location |
Building Capacity (a) |
Repair Capacity (a) |
Combined B/R Capacity |
Target Priority |
|
A. |
Kure, Japan |
28.0 % |
26.4 % |
27.2 % |
1 |
|
B. |
Yokosuka, Japan |
26.2 |
20.7 |
23.5 |
2 |
|
C. |
Sasebo, Japan |
19.3 |
27.2 |
23.3 |
5 |
|
D. |
Maizuru, Japan |
15.0 |
12.8 |
13.9 |
6 |
|
E. |
Port Arthur, Manchuria |
7.5 |
6.4 |
7.0 |
10 |
|
F. |
Ominato, Japan |
2.5 |
2.2 |
2.4 |
13 |
|
G. |
Bako, Pescadores |
1.2 |
2.6 |
1.9 |
16 |
|
|
(All others) |
|
1.6 |
0.8 |
|
|
|
TOTAL |
99.7 % |
99.9 % |
100.0 % |
|
|
COMMERCIAL YARDS |
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|
No. |
Name and Location |
Building Capacity (b) |
Repair Capacity (a) |
Combined B/R Capacity |
Target Priority |
|
1. |
Nagasaki, Jap. (2 yds.) |
26.0 % |
6.6 % |
16.1% |
3 |
|
2. |
Kobo, Japan (2 yds.) |
22.0 |
6.2 |
14.4 |
4 |
|
3. |
Osaka, Japan (6 yds.) |
8.0 |
17.2 |
12.6 |
8 |
|
4. |
Yokohama, Jap. (2 yds.) |
12.1 |
9.4 |
10.8 |
7 |
|
5. |
Okayama, Japan |
12.2 |
5.1 |
8.7 |
9 |
|
6. |
Shanghai, China |
– |
13.0 |
6.5 |
11 |
|
7. |
Harina, Japan. |
11.0 |
1.8 |
6.4 |
12 |
|
8. |
Innoshima, Japan |
3.3 |
9.0 |
6.2 |
14 |
|
9. |
Hiko Shima, Jap.(2 yds.) |
– |
6.3 |
3.2 |
15 |
|
10. |
Taku, China |
– |
4.3 |
2.2 |
17 |
|
11. |
Onomichi, Japan |
– |
4.1 |
2.1 |
18 |
|
12. |
Dairen, Manchuria |
– |
3.5 |
1.8 |
19 |
|
13. |
Hakodate, Japan |
0.9 |
2.8 |
1.7 |
20 |
|
|
(All others) |
4.5 |
9.8 |
7.3 |
|
|
|
TOTAL |
99.0 % |
99.1 % |
100.0% |
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SUMMARY: Japan's annual potential shipbuilding capacity (both naval and commercial vessels) is estimated to be 800,000 gross tons. Of this, about 250,000 tons may be allotted to navy yards and 550,000 tons to commercial yards. It must be noted, however, that the large commercial yards are important builders of all classes of naval vessels. In the assignment of priorities among the shipyards, equal weight has been given to merchant and naval tonnage as well as to building and repair facilities. Finally, certain qualitative factors, not shown in the statistics above, have influenced the over-all priorities. NOTE: Due to the lack of current data, such important yards as those at Soerabaja, Hong Kong, Singapore and Cavite have been emitted from this report. (a) Percentage based on total footage of ways or docks. (b) Percentage based on deadweight tonnage. |
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1. DESCRIPTION OF TARGETS
The shipbuilding yards comprise slipways, floating docks, cranes, gantries, machine shops, work shops, etc., etc. The plant layout varies so considerably that no reliable figures can be given for areas.
2. NUMBER OF DIRECT HITS AND TYPE OF BOMBS REQUIRED
In order to do effective damage both to the shipping under construction and the various shipyard facilities and work shops, it is considered that a heavy weight of attack should be made such that not less than 50 - 1000 lb. bombs fall within an area of 1000' by 1000'. Due to the dispersed nature of these targets, several aiming points varying from two to ten will be required to be taken for each of the various targets.
3. NUMBER OF SORTIES AND BOMBER FORCE REQUIRED
Based upon detailed calculations taking into account all operational factors involved in making attacks against highly defended targets with appropriate allowances for probabilities, aiming errors, losses, etc., etc., it appears that in order to make effective attacks upon the twenty (20) shipyards Included above, it will be necessary to fly:-
22,440 SORTIES
In order to carry out these sorties in sixty (60) operational days, a force of:
46 - B 29's and
298 - B 17e’s
must be set up.