<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:14pt"><div>Hi all,</div><div>This is my G.L. summary of Diving/Ballasting, Control/Compensating & Trimming.</div><div>It builds a little on a previous section "Stability & buoyancy".</div><div> All the ballasting controls & systems have to work under previously specified heel & trim <span style="font-size: 14pt;">requirements. Including when one main ballast tank is damaged.</span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt;"> It has to be possible to check these systems prior to diving.</span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family:
HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt;"> The sub must be able to surface after the failure of a compensating tank.</span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt;"> Flooding & bilge openings are to be protected with grids, filters or strum boxes to stop the entrance of foreign matter.</span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt;"> All the operating units for controlling positive & negative buoyancy are to be
grouped </span><span style="font-size: 14pt; background-color: transparent;">together & clearly marked on the control consul. This control consul is to have indicating instruments showing depth & trim.</span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt;"> Separate shut off valves are required for each ballast tank.</span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt;"> The vent valves are to be designed in such a way as to prevent unintentional opening.</span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica
Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt;"> Where diving tanks have flooding holes without means of closure, double shut-off</span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt;">valves "May" be stipulated for the vent pipe.</span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt;"> The blowing line for each tank has to have a separate shut off.</span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida
Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt;"> Blowing the tanks cannot cause an excessive over-pressure.</span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt;"> Where the diving tanks are pumped out there needs to be a closure valve & back up </span><span style="font-size: 14pt; background-color: transparent;">bilge pump. No excess under-pressure can be caused.</span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt; background-color: transparent;"> Compensating tanks are to be designed big
enough for all the changes in</span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt; background-color: transparent;">buoyancy plus 10%</span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt; background-color: transparent;"> Compensating tanks need contents gauges to give continuous readings.</span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt; background-color: transparent;"> The compensating
tank vent pipes need to be wide enough for maximum </span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt; background-color: transparent;">inflow / outflow </span><span style="background-color: transparent; font-size: 14pt;">and designed so that water can't flow from them unnoticed in to the hull.</span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt; background-color: transparent;"> The volume of the trimming tanks is designed in such a way that all planned trimming situations can be adjusted by combined filling & emptying of the various tanks.</span></div><div
style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt; background-color: transparent;">Alan</span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt; background-color: transparent;"><br></span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 14pt; background-color: transparent;"><br></span></div><div style="color: rgb(0, 0, 0); font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif;
background-color: transparent; font-style: normal;"><span style="font-size: 14pt;"><br></span></div><div><br></div></div></body></html>