Terry Spragg wrote:

Lew Hodgett wrote:

"TB" writes:

I have a new Henderson Mk V pump, will it be suitable for plumbing into
the system to empty the holding tank offshore, or will i need a specific
type. Any recommendations?



Henderson Mk V



I can use a bicycle pump or similar to evacuate my holding tank
offshore. I close both air vents, open the sea valve, and pump up the
holding tank with air. I watch the joker valve for back leakage / wear
indications, and now, use a 12 volt tire pump. When the pressure
reaches about a pound, out goes the poo.

If I did not open the sea cock, I could blow the contents out the deck
pumpout fitting. I have an elbo I am tempted to screw into the deck
fitting if ever any PWC gets too pesky, port side. Two elbows and a ball
valve could provide a fully aimable poo cannon. Long range shots might
be dangerous for the cabin crew / head attendant / leakage monitor. That
capability suggests a thru hull for sewage may not be required. I have
pressure tested the system when new with water. I can nervously saw I
would trust it to about 10 yards with short wait times at the ready.
Pirates? Bring 'em on!

This system also obviates no need for a working shoreside pump, and
requires only a holding tank on the gas dock, which could remove many
objections by marina operators about pumpout maintenance costs. It could
also make boats cheaper. Of course, a flexible vacuum hose to a parking
spot for a city services sewer sucker truck up on the bank would still
be needed. Oh, and a level indicating clear overflow tube / vent outside
the dock holding tank, wired to a pumpout service call buzzer / alarm. I
would not normally employ my system to blow sewage up more than about 3
feet, realistically.

Such a system would contribute greatly toward lowering shoreside pumpout
equipment costs, as a suction rated pumpout hose on the dock is no
longer needed. Mind, a leaky sewer hose on deck is quite noticable and
might be repaired more quickly than a plain cantankerous vacuum leaking
one.

Sell the pump.

Terry K

You Know how these things escalate, the pirates will go for bigger and bigger


holding tanks and i will soon be outgunned. I'll use the MkV.

Tony