Would you fit engine driven bilge pump?

[PhillM]

It looks like the re-engine is going to go ahead with a Beta either 14 with a 12 inch prop or 16 with a 13 inch. We don’t need hot water – but it can be retro fitted.

We are considering an engine driven bilge pump. This is a factory fit option and cannot easily be retro fitted. However, it adds about £700 to the job.

We have decent manual and electric pumps and of course the engine can charge the battery to keep the eletric pump running.

Paean is a 51 year old wooden boat. We do get a bit of water in (about 1/3 bucket every day). But we are in the habit of manually pumping every couple of hours – just to keep her dry. Sailing will be channel / coastal but you never know, one day we may go further.

What does the forum think, is it worth the extra to go with a third pump or would you save the money for somthing else?

 

[NB Willawaw]

Personally I would stay with decent electric pumps as they are effectively electrically driven through the alternator ?

Why do you feel that an engine driven one would be an advantage ?

 

[pvb]

We are considering an engine driven bilge pump. This is a factory fit option and cannot easily be retro fitted. However, it adds about £700 to the job.

What capacity is the pump?

 

[michael_w]

If I had the space I'd fit an Ericson Safety Pump Impressive stuff, compared to the puny output of most electric pumps

 

[pvb]

If I had the space I'd fit an Ericson Safety Pump Impressive stuff, compared to the puny output of most electric pumps

Really can't agree with you. From time to time, people suggest the Ericson pump, but never consider the implications. Yes, even the smallest size has a huge pumping capacity (but, crucially, not in a boat). The pump's theoretically rated at over 40,000 gallons an hour. But - and this is a big but - this rated capacity is at 3500rpm (pump revs). The average 30-40ft cruising yacht has a small diesel which will do maybe 3000rpm flat out, connected typically to a reduction gearbox (say 2.4:1 ratio), meaning that the prop shaft (which the Ericson pump is clamped around) is only turning at a maximum speed of around 1250rpm. At this slower shaft speed, the output is much less, maybe only 8000 gallons an hour.

Next problem: the Ericson pump is huge -the smallest model is about 10” diameter and about 5” front to back. There’s no way it will fit in my 35ft yacht.

Next problem: before it will pump efficiently, the aperture around the prop shaft must be fully submerged. So there needs to be a hell of a lot of water in the boat before the Ericson will start working properly. This would affect the boat’s stability somewhat (understatement!).

Next problem: it’s most likely that a dramatic leak will occur in the front part of the boat, and the Ericson is much further back. For it to work, it will be necessary to have a virtually open bilge right through the boat. With modern boat construction, stiffening ribs, etc, this is difficult to achieve.

Biggest problem: the pump only works well when the boat is flat out in forward gear. As “Motor Boat & Yachting” pointed out in its review of the Ericson pump “it is probably the case that most collisions involving breaches of the hull would damage the vessel's forward sections. In this case, driving the boat forward would tend to fill her and negate the usefulness of the pump”.

So, if you could fit one in, and if you could open up your bilges right through the boat, and if you thought that motoring flat out with a hole in the hull (and a lot of water sloshing around inside) wouldn’t be a problem, then an Ericson might shift 8000 gallons an hour. And it costs about £600. Why not get 3 big 12volt bilge pumps (say 3000 gallons an hour each) instead? They’d be cheaper, they’d work as soon as water got in, they’d chuck out at least as much water, and you wouldn’t need to be motoring flat out in order for them to work.

 

[fisherman]

£700 will get you a big Jabsco, fit it yourself, not complex.
http://www.jabscoshop.com/marine/pumps/bilge-pumps/bronze-engine-driven-clutch-pumps/

I had a manual clutch pump, but fed up with adjusting and renewing the clutch changed to the electric clutch 1.5" model in 2000. Not touched it since, The boat has done 10,000 hours, it has been on at least half the time. Even on tickover it does 100 litres in less than two minutes (depends on pulley size). It is primarily deck wash, then bilge pump, and has been used for the engine cooling in emergency. One thought, if the power to the clutch fails, so does the pump.

 

[Latestarter1]

It looks like the re-engine is going to go ahead with a Beta either 14 with a 12 inch prop or 16 with a 13 inch. We don’t need hot water – but it can be retro fitted.

We are considering an engine driven bilge pump. This is a factory fit option and cannot easily be retro fitted. However, it adds about £700 to the job.

We have decent manual and electric pumps and of course the engine can charge the battery to keep the eletric pump running.

Paean is a 51 year old wooden boat. We do get a bit of water in (about 1/3 bucket every day). But we are in the habit of manually pumping every couple of hours – just to keep her dry. Sailing will be channel / coastal but you never know, one day we may go further.

What does the forum think, is it worth the extra to go with a third pump or would you save the money for somthing else?

I struggle to think of the benifit......

For 'normal' bilge pumping elecric pump will do the job more effectively. Stuart Turner used to do a real neat little sea cock which had open, shut and bilge pumping position. In the bilge pump position it was real useful when surge of unchecked water is rising above engine bearers, however with rubber impeller pumps need to be treated with care and not run dry.

 

[fisherman]

...........rubber impeller pumps need to be treated with care and not run dry.

You can get 'run dry' impellers.

 

[bedouin]

I don't really see the benefit of an engine driven pump - they are expensive and their output is puny compared to even a cheap electric pump. It is hard to think of any situation where the engine driven pump would provide significant benefit.

Unless there is a failure of the electrics you will be able to shift more water with an electric pump than the engine pump, and even if the engine fails you are likely to have a lot of pumping time in the batteries.

If you have any specific concerns I would think that you can address them by spending a fraction of that on making you electrical pumps more robust - carry a couple of spares and maybe up the battery capacity.

 

[fisherman]

??
Depends what size of each you fit. Incidentally my bilge pumping is primarily electric, as I would have to change the manifold from deckwash for bilge pumping. Were I to need it I can run both and hand pump as well, and that is a lot of water.

 

[lw395]

I don't think I would fit one on an AWB, unless it was primarily wanted for deckwashing or something.
If you read up on what goes wrong on your average yacht, there do not seem to be many cases where sheer pumping capacity is an issue.
It is not as if you can be absolutely sure the engine will always be available instantly in an emergency anyway.

 

[greenalien]

Spend some of the money on the biggest alternator that will fit, plus an Adverc smart charger, plus additional batteries. Then fit a couple of electric bilge pumps. You'll still have enough change from £700 to buy an electric wash-down pump which can double as an additional emergency bilge pump - and enough battery capacity to run the pumps for hours, even if the engine isn't working.

 

[JimC]

... If you read up on what goes wrong on your average yacht, there do not seem to be many cases where sheer pumping capacity is an issue.

As a matter of interest, what are the more frequent issues?

 

[lw395]

As a matter of interest, what are the more frequent issues?

There is a book about total losses of yachts.

Main causes are collision, fire, stranding, anchor dragging IIRC, I read it some while ago.
What struck me about it was the way that for every case where somebody was adamant that (e.g.) floorboards must be easily lifted to find holes, there was another where floor boards need to be properly secured so that they don't hit you on the head when the boat rolls or fall into the bilge when they are floating around.

I think it gets very easy to plan your response to a specific mishap, then go out and have a different mishap.

 

[Salty John]

It looks like the re-engine is going to go ahead with a Beta either 14 with a 12 inch prop or 16 with a 13 inch. We don’t need hot water – but it can be retro fitted.

We are considering an engine driven bilge pump. This is a factory fit option and cannot easily be retro fitted. However, it adds about £700 to the job.

We have decent manual and electric pumps and of course the engine can charge the battery to keep the eletric pump running.

Paean is a 51 year old wooden boat. We do get a bit of water in (about 1/3 bucket every day). But we are in the habit of manually pumping every couple of hours – just to keep her dry. Sailing will be channel / coastal but you never know, one day we may go further.

What does the forum think, is it worth the extra to go with a third pump or would you save the money for somthing else?

If money were no object I’d certainly have an engine driven bilge pump. Whether you think the investment is worthwhile or not depends on how likely you think it is that you’ll suffer catastrophic hull damage, or lose a through hull fitting. In such an event you’re likely to be dealing with an inflow of more than 12,000 litres an hour. Commercial and professional boats tend to have engine driven emergency bilge pumps.

There is no electric submersible pump or electric diaphragm pump that will come close to coping with that. Submersibles lose capacity very quickly as pressure head increases. A 12,000 litre per hour pump will actually struggle to handle 4,000 litres per hour with any appreciable vertical lift and length of pipe, even with fully charged batteries. Diaphragm pumps tend to be of relatively low capacity – around 1,800 litres per hour at 3m pressure head for the Par 36600, for instance.

On the other hand a Jabsco 51270-9013 with a manual clutch will do over 16,000 litres per hour at 3m pressure head. It’s quite a big pump, though, at 12” x 8” x 5” and has a 7” pulley.

 

[JimC]

Main causes are collision, fire, stranding, anchor dragging IIRC,

Interesting to see collision heading the list. Most small cruising yachts, including mine have a triangular 'sleeping platform' in the bow forming part or all of the v-berth. Usually the cavity beneath this is accessed via lift-off plywood panels. I've often thought there would be some merit in replacing these by waterproof hatches on the grounds that holing below the waterline is most likely in the forward part of the boat.

 

[prv]

floorboards must be easily lifted to find holes, there was another where floor boards need to be properly secured so that they don't hit you on the head when the boat rolls

That's not all that much of a contradiction. "Easily lifted" doesn't have to mean "completely unsecured". A quality yacht would have recessed latches that hold the boards in place when closed, but can be quickly opened if required. I remember being fascinated by them as a small child on my grandad's boat . However, it's a hell of a lot cheaper to use screws, so most builders now do.

I think it gets very easy to plan your response to a specific mishap, then go out and have a different mishap.

That's certainly true - but hopefully the preparations for mishap A don't actively hinder a response to mishap B.

Pete

 

[bedouin]

??
Depends what size of each you fit. Incidentally my bilge pumping is primarily electric, as I would have to change the manifold from deckwash for bilge pumping. Were I to need it I can run both and hand pump as well, and that is a lot of water.

I was really meaning the sort of pump it is likely to be feasible to fit on a yacht in the 30-40' range. There is likely to be little room for installing a large item. I seem to recall when I looked into the the sort of unit I could fit was rated in hundreds of gallons per hour

 

[PCUK]

I'll be fitting an engine driven Jabsco next year. Huge output compared with any electric pump. Although it is clutched I'll be running it with the belt off the pulley but readily accessible for emergency use. I'll also be installing a manifold system to allow selection of the area to be pumped.

 

[Spyro]

If you have real emerency you already have an engine driven pump it's the cooling intake pump, just take the cooling water feed hose off the stop valve and fix it as low down in the bige as possible