[PSUBS-MAILIST] SeaQuestor progress

Sat Jan 19 02:00:28 EST 2019

Hi David,
how are you ballasting when you are diving without a passenger?
Alan 

> On 19/01/2019, at 5:19 PM, David Colombo via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
> 
> Hi Cliff, the vbt i was speaking of is actually the lower section of one of the mbt sections which would still be in use. The way my wings taper off there is an area that will work for a weight insert area that i think will work well.
> David
> 
>> On Fri, Jan 18, 2019, 11:46 AM Cliff Redus via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>> OK I understand.  The only problem about using a MBT near the CG as a VBT is that it is soft with an open flood port.  As such, it would be like a scuba divers BCD and require tweaking as you change depth.  I think better to used your added dumbbell weights at CG as your primary variable ballast and keep all the MBT flooded when diving then you don't have to correct for decreasing buoyancy with depth.
>> 
>> Have you calculated your Reserve of Buoyancy (ROB) for the boat assuming you use all the MBT for freeboard?  Should be pretty good.
>> 
>> Cliff
>> 
>> 
>> 
>> On Friday, January 18, 2019, 11:44:02 AM CST, David Colombo via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>> 
>> 
>> Hi Cliff, I actually have a combinatation of variable ballast. I have assumed a front pilot weight of 200lbs in my design. For increased weight above the 200 I have a system simular to the snoopy with the trawler floats that I can add. For lesser weight I have a rack design to recieve dumbell type weights that would be added under the pilot seat that can be easily adjusted for different passengers. In addition to the internal trim weight, which is a sliding rail system. I have also decided to reserve one mbt located at the cg line to be controlled independent of the other mbt for the additional control if I need it.
>> David 
>> 
>> David
>> 
>> On Thu, Jan 17, 2019, 5:31 PM Cliff Redus via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>> Still not clear on your Variable Ballast setup.  What you describe is trim system with a 100 lbs weight that you can move longitudinally  much like I use on the R300.  This will affect trim of boat but not buoyancy.  I am assuming you plan on having the MBT either 100% full on the surface or 0% full while submerged.  What do you do for different weight pilot and passenger?  You either have to add or subtract ballast like I do in a bay near the CG of the boat or you have a VBT that can you can take on ballast in terms of water to get the boat near neutral after MBT are flooded.  The third option on variable ballast is what Alec did on Snoopy which is to add or remove syntactic foam externally prior teach each dive.
>> 
>> Cliff
>> 
>> On Thursday, January 17, 2019, 2:40:19 PM CST, David Colombo via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>> 
>> 
>> Hi Cliff, I plan on doing a manifold system that groups together a couple of tanks for both port and starboard tanks and foward and aft tanks. I hope to use electric valves. The varible ballast is a worm drive 100# weight internal under my battery area. The external mbt will all be molded fiberglass shapped around the ribs between the pressure hull and exoskeleton, with the exoskeleton being one side of the tanks. I also plan on a lifting bag component at the nose area forward of the front pilot to be used to lift that pilot higher out of the water to increase the freeboard height of the ct for on station personal transfers.  Question, if i have a starboard and port tank, would you manifold them to a single valve locatation at the 12 oclock position, or use two valves to control each side. 
>> 
>> David
>> 
>> On Thu, Jan 17, 2019, 11:14 AM Cliff Redus via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>> Nice to see progress on your boat.  I love the pics.  On your segmented wrap around MBT, how are you going to vent the individual MBT segments?  Are you going to use pneumatic actuated vent valves like Alec has on Shackleton or are you going to try and manifold the vent piping and have single MBT vent valves on the port and starboard side?
>> 
>> Back to Hank's question, are you going to have a VBT or are you going to handle variable ballast like I do by adding ballast weights at the CG of the boat?
>> 
>> What are you going to make the MBT segments out of, plastic like polyethylene, polypropylene or layup FRP?
>> 
>> Cliff
>> 
>> 
>> 
>> On Thursday, January 17, 2019, 8:59:28 AM CST, David Colombo via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>> 
>> 
>> Hi Hank, we have a trim weight inside using a worm gear drive, and the main ballast tank is a series of wrap around tanks between the hull and exoskeleton.
>> David
>> 
>> On Thu, Jan 17, 2019, 5:34 AM hank pronk via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>> David,
>> Will you have a VBT?  Is the fibre glass shell acting as the MBT or will you have tanks?  
>> Hank
>> 
>> On Thursday, January 17, 2019, 4:46:14 AM MST, hank pronk via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>> 
>> 
>> David,
>> Looking sweet
>> Hank
>> 
>> On Wednesday, January 16, 2019, 8:59:28 PM MST, David Colombo via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>> 
>> 
>> Hi guys, started to build the work platform for the building of the SeaQuestor exoskeleton. I couldnt resist setting the stations to get a look.
>> David
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