I just sold my 1/48th Scale Shipyards Japanese "B" class boat. I had it for years sitting on the shelf and finally had to let it go for the room. The B class boats were slightly smaller than the 400's, holding only one plane, but they were still big!
Year(s) Completed 1940-1943
Displacement 2,584 tons / 3,654 tons
Dimensions 356.5 ft x 30.5 ft x 16.8 ft
Machinery 2 diesels: 12,400 hp
electric motors: 2,000 hp
Speed 23.5 knots surfaced / 8 knots submerged
Range 14,000 nm @ 16 knots
Armament 6x533mm TT fwd + 1x14cm/50 cal. (17 Torpedoes) + one seaplane
Max. Depth 100 m (330 feet)
Crew 94 officers and men
The Scale shipyards boat is close to 90" in length.