View Single Post
Old 03-31-08, 12:44 AM   #4
edjcox
Engineer
 
Join Date: Apr 2005
Location: Shang Gri La
Posts: 219
Downloads: 61
Uploads: 0


Put a bubble in safety... We might need to purge completely if the flooding continues. Blow her gently so as not to allow the enemy sonar operators the oppertunity to hear the roar of a balleast tank purge.

The safety enabled a small differential in bouyancy that floated the sub positive yet allowed planes and velocity to keep the vessel submerged at commanded depth without having to blow the main tanks. In combination with the comand flood negative or blow negative, the boyancy of a boat is more readily maintained and controllable. Often the boats bouyancy balance was crucial in an attack approach and setup against a listening adversary. With out these crucial settings the blowing of tanks is a noisy affair and can often warn an enemy surface combatant not only as to where you are but what you are doing. Ideal neutral bouyancy was a constant balancing act with temeprature, salinity, and operating depth all factors.
A limited compressed air supply could be extended if a boat was primarily running slight positive bouyancy and using planes and velocity for depth maintenance. Only in emergencies and crash dives would one open all the bllast tanks and take on the tons of water to claw down to the deep and silent world of submerged safety. The captain and crew that did this imprudently or did so with holed or leaking tanks are mostly still out here on permanent patrol.

So "put a bubble in safety" means to get the boat to positive or near postive bouyancy so that the planes, forward velocity, an a slight purge of the main tanks would send her back up to the surface realm. Once at the surface low preassure turbo blowers would charge the main tanks and float the sub above the water...

An intial surface condition often had little freeboard unless the captain and crew were sure they could recharge their air they used to blow....

Laters

edjcox is offline   Reply With Quote