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Passagemaking Under Power List

Bluewater Bilge Pumps

alweld@comcast.net

Tue, Oct 25, 2005 3:36 AM

Thanks to all the list members that provided a response regarding the value of a manual bilge pump on an ocean-going motorboat.

There were a total of eleven responses on and off list.

Six responders viewed the manual pumps as a positive asset.

Four responders, myself included, felt the manual pump was of no practical value (my interpretation of the others responses).

One responder detailed a very comprehensive electric and mechanical pump system in his own boat, but there was no manual pump. So I'll take the liberty to throw this to the nay group.

So there it is.

There were some very good suggestions regarding portable pumps, and backup pumps (spare pumps that could readily be put into service).

I think that I'll put my resources into an additional 12V high capacity submersible that will be plumbed but normally electrically isolated. With the jumper cables that I'll carry and three separate battery power sources (four if I were to carry a small inverter/gen like a Honda) there should be power available if the immediate source is not.

I consider the risk of flooding at sea rather remote, undoubtedly much more likely to get run down by a ship, and a pump likely wouldn't matter at that point. The bottom is 1/4" steel, with a crash tank forward, and I doubt that a semi-submerged container would make more than a dent. I don't have any below the waterline thruhulls, and the sounder transducer is isolated in its own vault. The only seawater entering the boat is for the watermaker and the fire pump, and those are standpiped to above the waterline. The greatest risk of flooding is from the shafts and stuffing boxes. The main shaft couldn't slide out because it would hit the rudder. The small shaft could escape but it's only 1" dia. and would be easily plugged. Has anyone any knowledge of a stuffing box seizing to the shaft and shearing the hose coupling?

Thanks again for your responses,

John Crowley

Thanks to all the list members that provided a response regarding the value of a manual bilge pump on an ocean-going motorboat. There were a total of eleven responses on and off list. Six responders viewed the manual pumps as a positive asset. Four responders, myself included, felt the manual pump was of no practical value (my interpretation of the others responses). One responder detailed a very comprehensive electric and mechanical pump system in his own boat, but there was no manual pump. So I'll take the liberty to throw this to the nay group. So there it is. There were some very good suggestions regarding portable pumps, and backup pumps (spare pumps that could readily be put into service). I think that I'll put my resources into an additional 12V high capacity submersible that will be plumbed but normally electrically isolated. With the jumper cables that I'll carry and three separate battery power sources (four if I were to carry a small inverter/gen like a Honda) there should be power available if the immediate source is not. I consider the risk of flooding at sea rather remote, undoubtedly much more likely to get run down by a ship, and a pump likely wouldn't matter at that point. The bottom is 1/4" steel, with a crash tank forward, and I doubt that a semi-submerged container would make more than a dent. I don't have any below the waterline thruhulls, and the sounder transducer is isolated in its own vault. The only seawater entering the boat is for the watermaker and the fire pump, and those are standpiped to above the waterline. The greatest risk of flooding is from the shafts and stuffing boxes. The main shaft couldn't slide out because it would hit the rudder. The small shaft could escape but it's only 1" dia. and would be easily plugged. Has anyone any knowledge of a stuffing box seizing to the shaft and shearing the hose coupling? Thanks again for your responses, John Crowley

John Harris

Tue, Oct 25, 2005 4:16 PM

John,

Yes - the Race Committee boat for one of the Yacht clubs on Long Island
Sound had a main shaft seal freeze on the prop shaft and tear out some years
ago. The crew was able to get a Coast Guard Cutter along side quickly with a
high capacity pump. They were towed to a harbor with a lift for repair.

I was not aboard at the time but I was aboard the boat a week later, after
it had been repaired - it was not seriously damaged beyond the modest
flooding that occurred before the Coast Guard arrived. I do not know what
type of seal was on the shaft not the details of the failure.

Regards, John Harris

-------- original message ---------------------------------
The greatest risk of flooding is from the shafts and stuffing boxes. The
main shaft couldn't slide out because it would hit the rudder. The small
shaft could escape but it's only 1" dia. and would be easily plugged. Has
anyone any knowledge of a stuffing box seizing to the shaft and shearing the
hose coupling?

John, Yes - the Race Committee boat for one of the Yacht clubs on Long Island Sound had a main shaft seal freeze on the prop shaft and tear out some years ago. The crew was able to get a Coast Guard Cutter along side quickly with a high capacity pump. They were towed to a harbor with a lift for repair. I was not aboard at the time but I was aboard the boat a week later, after it had been repaired - it was not seriously damaged beyond the modest flooding that occurred before the Coast Guard arrived. I do not know what type of seal was on the shaft not the details of the failure. Regards, John Harris -------- original message --------------------------------- The greatest risk of flooding is from the shafts and stuffing boxes. The main shaft couldn't slide out because it would hit the rudder. The small shaft could escape but it's only 1" dia. and would be easily plugged. Has anyone any knowledge of a stuffing box seizing to the shaft and shearing the hose coupling?