Fortunately , in 1944 a redesigned Gould centrifugal pump replaced the noisy early - war pump , and effective diving depth was increased .
Cochrane , Chief of the Bureau of Ships , to limit test depth to 400 ft ( 120 m ) .
In 1944 a redesigned Gould centrifugal pump replaced the noisy early - war pump , and effective diving depth was increased .
Cochrane , Chief of the Bureau of Ships , to limit test depth to 400 ft ( 120 m ) .