What do you all think of engine-driven bilge pumps?

[sanibel sailor]

I am hesitant to swim in a marina with all the shore power on. Now I am going to be wading around, waist deep, likely in the dark (isn't it always dark when the shinola hits), with submerged 120V AC. I may not last long enough to drown!

[Andrew Troup]

Evans - that's a great list.

I hadn't fully considered the "metal stuff can fall...and jam in the engine ...belts"

I guess it's my natural inclination not to leave anything loose in the engine room, but I must admit that when I've carried out the thought experiment of imagining the boat rolled over and picked up by a crane and thoroughly shaken, I've never looked for things on (say) the floor of the engine room which might break free - sometimes with fairly minimal encouragement. Or such things as a 'wander light' ... So thanks a lot for that.

And you're right, I think, to say that all the points in your list can be addressed. And they are routinely addressed, eg in UK by the Royal National Lifeboat Institution specs (and presumably the Nth American Coast Guard organisations)

I must check back and see if there are any threads about these measures; if not, it would be interesting sometime to start one. I have a couple of ideas, frinstance, about fuel breathers which may not be in wide circulation.

And I'd like to better understand the oil mist separators which Yanmar (presumably among others) fit, presumably to the crankcase breathers and air filter/sump connections, to engines destined for lifeboats. These are rated for running without a hitch throughout a 360deg event.

[Andrew Troup]

Hmmm - didn't find a thread on engine installations for inversion, but I did find this, which is a bit sobering (these guys were just practicing - no pressure...)

http://www.cruisersforum.com/forums/...tml#post149350

[Andrew Troup]

Evans
Your point about affordable and reliable AC pumps for industrial submerged service is well taken, and if I had a genset I'd certainly follow your lead.

When I think of designating a 'pump of last resort', independent of electrical supply, for me it's a mindset to arrive at a high degree of rigour in planning, design and installation.

It's not by way of suggesting that other, supplementary pumps, dependent on electricity, might not end up being necessary and/or sufficient.

Those who talk of clogging making pumps inoperative might want to carry out the above thought experiment after mentally filling the boat with water and leaving it to marinate for a while.

It seems to me that carefully thought out stowage provisions for a serious offshore vessel (especially for things like books and paper charts, glass bottles and jars, etc) can address most potential clogging issues, and then it's up to good housekeeping, especially when bad weather is expected.

The aim is to cap the potential level of debris below what decent (ie oversized) strum boxes can handle. These should be fitted on flex hoses, with lanyards so you can haul them up out of their sump to clear them.

The strum box hooked up to the pump best equipped to pump debris should have really big holes, and be at the bottom of the deepest sump, with other pumps' strum boxes above it, if they have to share that sump. (I'm assuming the sump is big in relation to the strum boxes: if close-fitting, this order would need to be reversed)

And, if it's feasible to provide enough pumping capacity to gain on a major leak, then you have a fighting chance of finding it. I can't stress too much how difficult it can be finding a leak which is below the level of the water in the boat, unless the boat is a bare, uninsulated shell.

And if you can't find it, I can't see any value whatsoever in a rule which says you have to staunch it before making a serious attempt to get the water level down. The leaks on the Bounty were almost certainly unstaunchable without a dry dock and a team of shipwrights, but as Evans observed, if some of the pumps had worked properly, they had sufficient capacity to buy the time to save the boat.
They could, for instance, have flown out backup personnel and pumps, then fothered the leaks, once the conditions had moderated.

Even on a boat the size of ours, it could easily take hours just to locate a leak low in the hull, and large fractions of a day to staunch it. And it occurs to me that taking to the woodwork with an axe is hardly conducive to keeping the pumps from clogging.

One thing that people who've been through this generally report, is that their brains do not work at all well during the period when the water is gaining, especially at the beginning of that period ... I would personally rather have a known and practiced task to carry out, to get me through that "shocked and stunned" phase, such as getting all the big pumps going, than trying to take on something as unscripted and unscriptable as finding a concealed point of ingress.

[Andrew Troup]

Last thought: To anyone installing or carrying a seriously large-capacity pump: it could be worth giving some consideration to carrying an intake hose long enough to reach across to another vessel. It's pretty traumatic watching another boat sink alongside you for lack of pump capacity, and it can happen in conditions quiet enough to raft alongside.

If your vessel is shoal draft with big tankage, such a hose can also save a lot of time refilling the watertanks from a decent stream.

(I've now exceeded my self-imposed post quota, so you may be relieved to hear I'm signing off until another day!)

[estarzinger]

Originally Posted by Andrew Troup

Evans - that's a great list.

I hadn't fully considered the "metal stuff can fall...and jam in the engine ...belts"

.

I was interested, when divers finally found the Aegean engine, that they found a spare anchor rode (chain and rope) had wound around the shaft and transmission. We think it was stowed somewhere low and aft in a duffle bag and somehow found its way to the shaft where the duffle was ripped open and the chain wound up around the shaft. Its sounds improbably, but we have photos so it did actually happen.

[S/V Alchemy]

I find this a very helpful thread. We so often select to ignore the worst-case scenario, but that is wishful thinking. Considering what could foul one's bilges is an important part of planning for such a case. I vaguely recall that some voyager back in the day found his well-planned bilge pump solution was defeated by an open sack of flour or corn meal (I can't precisely remember) which clogged his pumps and left him with several days of two feet of water in the boat. He survived, but it was an avoidable trial.

And people wonder why I'm such a hard case about positive hold-down on cabin sole hatches...it's because you have to think "what would fly loose if we rolled?"

Not everyone will roll, but if you do and your gear is not secured, a fixable mishap could quickly turn into a death sentence.

[Dave22q]

engine driven bilge pump might be ok as an emergency back up only. in an emergency u do not want total dependance on engine not failing. stick with battery powered and possibly a manual backup. generally if the water gets to your batteries its time to grab you bailout pack. hopefully you were on the radio for help before you lost power or you have a portable.

[David M]

Originally Posted by foolishsailor

My understanding is that the raw water cooling pump moves very little water...what you see coming out your exhaust is the effective volume of water...nothing compared to even a small dc pump.

That depends on the size of your engine. The raw water coming out of my 330 HP diesels exhaust is significant, even at idle. For a 20 HP Diesel that would be much less. Something though is better than nothing and it is still probably more water volume than what you could get with a hand bilge pump or a bucket brigade.

[goboatingnow]

Having been all over the All-weather RNLI lifeboats (Im involved in the RNLI) You cant afford to build or buy "a worse case scenario " vessel. Thats really why they dont exist on yachts. Ive yet to set foot on a yacht where an inversion doesnt cause havoc, with lockers bursting open, food spilling and misc objects flying about the place, and there the good vessels.

Manual pumps have a place but they are no substitute for well engineered mechanically driven pumps. The problem is of course that few of us , outside the SAR services are prepared to pay the cost of such engineering.

I seen what the RNLI do to ensure engines and the boats survive a 360, and keep going ( actually the engines auto return to a tick over) and theres no way you can afford it.

Dave

[Andrew Troup]

The electrical system in sailboats is frequently problematic once a bit of the wet stuff from outside the boat starts surging around inside the boat.

It doesn't have to be deep enough to uniformly submerge items like alternators, switchgear, or battery vents: it's often a death sentence if it simply sloshes over them.

Whereas, if the figures Evans posted further up this page are representative, there's about an even chance of even a standard propulsion-diesel installation being usable after a near 180 inversion, and presumably that would be considerably higher if a non-electric start option were fitted.

Here's an example I just came across
http://www.cruisersforum.com/forums/...tml#post809120

This quote starts 19 hours after their major knockdown:

<< On the evening of Friday, around 18:00, we started the engine to recharge the batteries. I immediately felt a burning smell and smoke coming from the engine compartment. We stopped the engine and made an investigation of the engine compartment. We believe that there was an electrical short with possible wire melt down and blown fuse. Impossible to start the engine any more...>>

They had been taking on water from places unknown ever since sustaining some damage in that knockdown. The electric pumps had been well able to cope, but it was harder to keep up with manual pumps now that the batteries were flat.

This, combined with further bad weather and concern that they would lose the ability to communicate, led to the decision to abandon.

It seems entirely possible from a closer reading of the accounts in this thread (both by the captain and one of the crew) that this decision was largely dictated by the unavailability of electrics, in a situation where the continued safe operation of the vessel was not possible in their absence (particularly the autopilot and the pumps)

I personally think such reliance has become an achilles heel on many seagoing boats, and I don't think it needs to be.

[carstenb]

Originally Posted by estarzinger

I was asked to provide an "independent expert opinion" specifically on the chosen sailing route. To do a proper job of that assignment I felt I needed to understand the full status of the vessel and equipment and crew, which is why I now know more about her pumps and refit and crew resumes that I want to. It took me 6 pages of text and 22 exhibits to provide what I though was a complete and accurate assessment of the sailing route.

I agree with you that the captain made simple, avoidable mistakes, and he will be found responsible for them. But I also believe he did not make those mistakes in a complete vacuum. He was added and abetted and supported and even encouraged by multiple other people, professionals, institution's, regulations, and culture. If the final USCG report simply says the captain made mistakes, then it (probably not identical mistakes but similarly avoidable tragic mistakes) will happen again and again, because the same support structure for those mistakes will be left in place.

But back to the thread and pumps . . . . one thing you can certainly learn is that pumps both need to be used and maintained. Its easy for them to corrode with no use, and its easy for them to degrade in performance with use. The Bounty was certainly grossly deficient in their pump use/maintenance procedures, but they were not unique in this. I know several mega $ superyachts with highly regarded captains that for instance have emergency crash pumps that have not been tested in years. The people reading this thread can ask themselves when was the last time they dissembled their pump to but sure there was not hair or other debris wrapped around the shaft (above the impellor) which can cause friction and dramatically reduce capacity. When was the last time you checked each and every electrical connection in the circuit for voltage drop. These things demand a disciplined and systematic approach, but that is missing and is in fact 'counter cultural' (or just "too expensive") in some parts of the 'yachting' world.

Evans,

Would you care to start a new thread and tell us a bit more about the Bounty? I tried to follow the hearings on the net, but that was difficult.

Certainly, I, and most others feel that the decision to set sail was a bad one. And once out there, the decision to not seek harbor, was worse.

Thanks

[Andrew Troup]

Another story ending in abandoning a yacht, essentially because of reliance on electric pumps in a situation where, with a high capacity pump, they would in all likelihood have been able to lower the internal water level sufficiently to discover the source.

<< ... account by Angela Myer, from her brutally honest book SEA FEVER

... her partner made the tragic decision to turn back from their trip home (to NZ) - they were sailing from Colombia to the Galapagos - because the engine was playing up and he wasn't confident of getting into a refuge on an isolated stretch of the Ecuadorian coast, relatively nearby, without it.

Unable to make headway in the direction they thought they now needed to go, and exhausted beyond the power of rational thought by having to pump continuously for the last five days to keep up with a hull leak they could not stem (electrics down....)>>
they made the decision to abandon their trip.I think they also abandoned the yacht - but I don't (yet) have a copy of the book.

She's a friend of a close relative, so I may at some future date be able to get the story from the source.

[Pelagic]

This was discussed recently.
http://www.cruisersforum.com/forums/...ump-76344.html

I have a 2” electric clutch pump running off the PTO… similar to this Jabsco
Jabsco 50270-2311 - 2" bronze pump, 270-size, foot mounted with BSP threaded ports / Bronze Engine Driven Clutch Pumps / Bilge Pumps / Pumps / Marine / Xylem JabscoShop - Jabsco & Rule Pumps and more - from the experts

[Pelagic]

Originally Posted by estarzinger

....But back to the thread and pumps . . . . one thing you can certainly learn is that pumps both need to be used and maintained. Its easy for them to corrode with no use, and its easy for them to degrade in performance with use.... I know several mega $ superyachts with highly regarded captains that for instance have emergency crash pumps that have not been tested in years. The people reading this thread can ask themselves when was the last time they dissembled their pump to but sure there was not hair or other debris wrapped around the shaft (above the impellor) which can cause friction and dramatically reduce capacity. When was the last time you checked each and every electrical connection in the circuit for voltage drop. These things demand a disciplined and systematic approach, but that is missing and is in fact 'counter cultural' (or just "too expensive") in some parts of the 'yachting' world.

Excellent observation and for those of us who enjoy dry bilges….. an important reminder!

Emergency Pumps should be tested every month as part of your safety drills. So that requires some thought on how to do this without flooding your bilges.

On the SY’s where I have been involved in the specifications and management, the independent hand start diesel fire pump (located outside the Engine room) was tested every month and fire hoses pressurized.

Every crew member including the Stewardesses had to be able to start this hand crank diesel pump.

However this pump’s intake was also tied into the bilge pump manifold, so was a last resort emergency dewatering back up, if the large electric bilge pumps motors failed during a fire fighting event.

I now realize I have missed this multifunctional use with my own engine driven crash pump, so will look at plumbing in a thru hull and a fire hose take off, so as to have a fire pump which would also facilitate pump testing.

Before I just packed the impeller with Vaseline and tested once a year by flooding Engine room Sump