The Offshore Voyaging Reference Site

Crash Pump

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The sound of gushing water from below has got to be right up there on any voyaging sailor’s list of worst nightmares. On Morgan’s Cloud, given that we believe that any pump that is practical for a yacht, no matter how powerful, is going to be of limited use in a flooding situation, we have always pursued a strategy of prevention, coupled with the gear and training to quickly stop a leak if one did occur.

But two of the comments to our recent bilge pump post got us rethinking:

  • Matthew pointed out that the pump we put such faith in is not thermally protected and will likely burn out in under an hour in an emergency situation.
  • Dick pointed out that large manual bilge pumps, like our huge Edson, are really pretty useless for a short handed crew because they are exhausting to operate and, worse still, using them will distract the crew from what should be the primary goal in a flooding situation: find and plug the leak.

Thanks to these two comments, and the others on the post, we came to the following three conclusions:

  • Our bilge pumps on Morgan’s Cloud were not adequate to at least slow the rising water while we looked for the cause of flooding, or to pump out the huge volume of water that might be left in the boat after we (hopefully) found and plugged a bad leak.
  • That we needed a pump that would run continuously for long periods and that would automatically cycle on and off using thermal protection if it did overheat.
  • There was no recreational electric bilge pump that was large and robust enough to do the job and had thermal protection.

So we went looking for an alternative in the commercial and industrial world and found a good solution.


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Dennis K. Biby

Interesting in the sense that a former girlfriend defaulted to engine starting in a crisis. Works great IF the engine starts but if it doesn’t the crisis becomes starting the engine – not sailing oneself away.

A hole four feet below the waterline spews a 1.73 psi geyser of water. See http://www.kylesconverter.com/pressure/feet-of-water-to-pounds-per-square-inch

Perhaps tis better to stuff a sock, plug, or … in the hole, a simple solution while others ignite the engine, rely on bilge pumps, or waste time trouble-shooting same.

Dos centavos,

Dennis
s/v Ferrity

apt George Wall

Which is precisely why water detection should start with detecting traces of any water (or at a very low level before pumping begins) in an otherwise dry bilge. Waiting to start looking until when the “high water alarm” goes off or pumping starts, puts you behind the power curve in locating the source of the water.

Charles Starke

Great article!
How come you bought the 1/3 hp vs. the 1/2 hp?
It has larger diameter and flow output.
I am selling my large aluminum Edson on a board. Anybody want one?
Thanks!!!!

Steve A

Hi John,
I have also been looking for a back up AC “crash” pump, and this one goes to the top of the list as I trust & respect your research & opinion. Can’t have too many pumps or redundancy. I wonder how long it could run dry before it burns up? Seems like the auto switch would be a good idea, rather than stationing someone to moniter water level at the pump.
My primary dewatering pump is a hydraulic Stanley SM21. It is made for use by utility companies to lower down manholes. Ok to run dry, pumps solids. According to the specs it pumps a staggering 5 gallons per second, 300 gallons per minute (1135 lpm) 18,000 gph, 50′ head max, 2 1/2″ hose. If you could direct the discharge stream it would probably propel the vessel! Weighs 20lbs, 6″x16″. Needs a 4-9 gpm hydraulic pump to power it, like a Vickers VTM42, which is a fairly small and common pump, though I installed something larger.
I agree that adding hydraulic pumps, compressors or alternators to the front of an engine is not the ideal solution. My dream engine or gear will accept a bolt on hydraulic pump…..however my Volvo has a bracket on the front to mount accessories on. My previous (commercial) vessel had an engine on flexible mounts and a hydraulic pump mounted to the hull. This was installed by the previous owner and as it was my first inboard I never gave it any thought. I discovered the misalignment while under full power and was shocked, it was obvious to the naked eye, but it was in the middle of a long summer season and there was no stopping to fix it. I carried a spare pump & clutch for a quick swap out, which was needed at 4,000 hours. The bearings on the $150 electric clutch were shot. I’m amazed that it didn’t eat belts (I kept them fairly loose) and the misalignment probably wasn’t doing the front end bearings any favors. I sold that boat with 9,000 hours on the engine and it is still going strong. I don’t advocate abusing machinery & would never install a pump like that myself….but feel pretty confident with a well aligned pump on a bracket that moves with the engine. That said I do carry several sets of belts, and a spare electric clutch.

richard s. (s/v lakota)

i still think it’s a good option to be able to switch the engine raw water intake from outboard to inboard including a well mounted and robust strainer for the inboard line…this could be just one of several remedies for flooding…probably can’t have too many…also means activating the valve switch from time to time probably using a sizable bucket to hold the water for the engine to pick up…just flipping the valve switch occasionally is obviously not enough to be really sure the option will work when and if really required although this is better than nothing when the bucket is occasionally just too inconvenient…cheers

richard in tampa bay

Svein Lamark

Hi John,
I think this is a good idea. I have had a pump like that for years and it works good. It is also an advantage that the pump is portable, you can move it around in the ship if necessary or also important: Help another ship that has a leek. Most yachts does not have a large portable pump, so if you inform The Coast Guard on the radio that you have that pump, you can be ordered to save another boat. This has happened to me and it ended good.
In Europe you can get cheap versions of this pump made of plastic, not polished stainless steel and they have a floating switch. The price is around 10% of yours. I have had one for many years and it is still working, but of course the quality is not the same as yours. On the other hand it is better than nothing.
Most marine diesels have a large pump built into the engine (in opposition to car engines converted to boat engines). This pump will always run as long as the engine runs to keep the engine room dry. Even if I have such a pump, I go for your solution because I feel safer that way.

Joris

Hi Svein, which pump could I get in Europe? I’m living in the Netherlands and preparing for an Atlantic trip next year. We’d like to buy a European version of the pump.