Ballast Indicators

Rambler241 · 03-29-16, 03:54 AM

Indeed - the boat was trimmed to positive buoyancy on the surface, set to neutral to dive, and the planes did the rest. Maintaining level buoyancy trim was crucial while at periscope depth, and the planesmen had the important responsibility of maintaining depth - a loss of trim or depth on entering fresher (less dense), or more salty (denser) or warmer or colder water could result in the bow (or stern) breaking water.

In Das Boot, remember the crew running for'ard to compensate for the loss of weight in the bow when a torpedo was fired? I thought I'd spotted a technical error in an early (post WWII) British sub movie - there was no such rush forward on firing torpedoes, and no obvious action taken by the crew to compensate. Turned out, after a little research, I was wrong - most British boats of the period had automatic ballast shift to compensate for the loss of weight.

03-29-16, 03:54 AM	#5
Rambler241 A-ganger Join Date: Aug 2014 Location: High Wycombe, UK Posts: 76 Downloads: 5 Uploads: 0	Indeed - the boat was trimmed to positive buoyancy on the surface, set to neutral to dive, and the planes did the rest. Maintaining level buoyancy trim was crucial while at periscope depth, and the planesmen had the important responsibility of maintaining depth - a loss of trim or depth on entering fresher (less dense), or more salty (denser) or warmer or colder water could result in the bow (or stern) breaking water. In Das Boot, remember the crew running for'ard to compensate for the loss of weight in the bow when a torpedo was fired? I thought I'd spotted a technical error in an early (post WWII) British sub movie - there was no such rush forward on firing torpedoes, and no obvious action taken by the crew to compensate. Turned out, after a little research, I was wrong - most British boats of the period had automatic ballast shift to compensate for the loss of weight. __________________ There are only two kinds of vessels; submarines and targets.