RE: [PSUBS-MAILIST] Sound Absorption

[Hugo Marrero <HMarrero@hboi.edu>]

In our sub we have an external hydraulic pump. The pump also monitors the
ambient pressure so that the hydraulic pressure is always constant above
ambient pressure. This gets more complicated, but it keeps the noisy
components out of the hull. It can also get very expensive, so make sure you
have deep pockets... some of the valves we use are for aircraft hydraulic
systems and as you know, anything "aircraft" is very expensive.

Hugo