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ridgewayranger · 02-10-07, 07:52 AM

Hi,
This applies to British pre Nuke boats.
Klaxon pressed on bridge or verbally,Dive the boat. This depends on whether the full crew is to be used or just the watch.
Main engines are stopped and motors started, Full ahead if Klaxon initiates the dive.
Planes Hard to dive.
Main vents opened in sequence from forrard to aft, if 'crash' dive is needed, Q tank is flooded and holds about 10 tons. As soon as boat starts down, Q must be blown, for obvious reasons. At depth ordered, OOW catches the trim by juggling water between trim tanks and reduces speed to conserve battery.
Depth changes are achieved by pumping and flooding internal tanks, planes and speed.
It may seem strange but when going very deep it is necessary to pump out water, because the compression of the hull reduces displacement and in effect makes the boat heavier.
Compressed air is only used for surfacing, and then only enough to get positive buoyancy. Full buoyancy is gained by starting a low pressure air pump known as the L.P.Blower, this is usually started before the hatch is opened, to remove excess air pressure in the boat( It has been known for the hatch opener to be blown clean out of the tower!) If the boat is in an uncontrollable dive ballast tanks will be blown completely, along with fervent prayers!!!
Having served in British S T & A classes as HSD (senior sonar rating) then TI ( senior rating in charge of Torpedo Department), I'd be glad to answer any questions, perhaps privately, to avoid boring those who already know it all.
RR.

02-10-07, 07:52 AM	#14
ridgewayranger Frogman Join Date: Jul 2005 Location: Ipswich, England Posts: 302 Downloads: 281 Uploads: 0	Diving Procedure Hi, This applies to British pre Nuke boats. Klaxon pressed on bridge or verbally,Dive the boat. This depends on whether the full crew is to be used or just the watch. Main engines are stopped and motors started, Full ahead if Klaxon initiates the dive. Planes Hard to dive. Main vents opened in sequence from forrard to aft, if 'crash' dive is needed, Q tank is flooded and holds about 10 tons. As soon as boat starts down, Q must be blown, for obvious reasons. At depth ordered, OOW catches the trim by juggling water between trim tanks and reduces speed to conserve battery. Depth changes are achieved by pumping and flooding internal tanks, planes and speed. It may seem strange but when going very deep it is necessary to pump out water, because the compression of the hull reduces displacement and in effect makes the boat heavier. Compressed air is only used for surfacing, and then only enough to get positive buoyancy. Full buoyancy is gained by starting a low pressure air pump known as the L.P.Blower, this is usually started before the hatch is opened, to remove excess air pressure in the boat( It has been known for the hatch opener to be blown clean out of the tower!) If the boat is in an uncontrollable dive ballast tanks will be blown completely, along with fervent prayers!!! Having served in British S T & A classes as HSD (senior sonar rating) then TI ( senior rating in charge of Torpedo Department), I'd be glad to answer any questions, perhaps privately, to avoid boring those who already know it all. RR.