Bilge pumps

[Wakatere]

Wakatere currently has a single maunal bilge pump and I'd like to add electric pump(s). The heads bilge forward and the engine bilge aft (surprise) are separate from the main bilge for small amounts of water. I had thought to have small pumps draining the small areas into the main bilges and then a larger one to evacuate that. This would only require one additional hole in the hull, but it seems a pity to have any pump not contributing to shifting water out of the boat in an emergency.

Any advice?

 

[prv]

I'd suggest the engine bilge not be linked to the main bilge. Assuming it's likely to get oily, you don't want that oil spread throughout the boat. On the other hand, in this day and age pumping it directly over the side would be frowned on too. In my boat, I have no pump in the engine bilge, and on the rare occasions it needs emptying I bail it out with a small jug and a sponge. I was planning to fit a small brass cylinder pump I had lying around, in such a way that it could pump cleanish water direct into the main bilge, or oily water into a bucket for disposal, but I never got around to it.

If I had a heads bilge, I think I probably wouldn't want that draining into the main bilge - certainly not if a shower is involved. So a small electric pump seems like a good idea. Either centrifugal (probably cheaper) or diaphragm (won't clog up with hair etc - again, required if there's a shower). The outlet can be well up the side of the hull, just below the gunwale, so not a "hole in the hull" in the sinking-at-the-mooring sense. You will have to think about backflooding when heeled over though, especially if the heads is forward.

Pete

 

[Simondjuk]

Given that bilge pump outlets will be above the waterline, and therefore don't create any further sinking risk due to failure, I'm not sure why you'd have any concerns about making more than one additional hole for them in order to gain the benefit of all pumps discharging overboard.

As for pumps in the engine bilge, I'm not keen. They will discharge any oil and fuel which may have leaked along with the water they pump. Much better to get the engine oil, fuel and water tight. Similarly the shaft seal.

 

[pvb]

Easiest solution for preventing oily waste being discharged is to use a polypropylene oil absorbent pad in the engine bilge area.

 

[Salty John]

I agree with prv that the engine bilge needs special treatment. You might want to consider giving it its own small electric pump but with no automatic switch. Keep an oil absorbing pad in the engine bilge and the water should be ok to pump out, keeping it on a manual switch gives you some control over when and where you pump.

Often the engine bilge inconveniently divides the main bilge so that water from the stuffing box can't flow into the main bilge, so you need duplication of pumping systems. If you can arrange it, an engine sump hanging under the engine but above the main bilge works well, or you can run a pipe through the engine bilge to achieve the same thing - uninterrupted flow from end to end of the main bilge without contamination from the engine droppings.

For the shower I prefer a separate sealed sump with filter and automatic switch. Keeps odors at bay and prevents hair clogging up the main bilge pumps.

All other areas can be served by your manual pump and electric pumps as appropriate. Some thoughts on bilge pump systems here:
http://www.saltyjohn.co.uk/resources/Bilge_pump_system_design.pdf

 

[fisherman]

Not sure if this will help you, but some French built FVs had a hopper on deck into which all water outlets were directed, with one big drain overboard, so you could instantly see if a bilge scavenge was working overtime, indicating a problem. So you could have a hopper, say, in a corner of the cockpit connected to your existing outlet with all your bilge pump outlets going to it. Useful for peeing in as well.

 

[eagleswing]

my bilgepump set ups..nauticat 321

for the engine bilge --due to very large possible $10,000 to $100,000 fines in the USA for dumping oil overboard, i choose to not have an automatic bilge pump serving the engine bilge. instead i have a $10 plastic portable pump whose input line ends in a rigid copper tube which inserts into the engine bilge. the pump installs to a jubilee clip in the engine compartment and the output side of the pump has a hose that goes into a waste bottle . that pump w as handy when the engine blew an oil cooler line...

for the shower bilge: i have a manual hand pump mounted on the sink that one must use to pump the shower water into the head sink. (this requirement teaches people not to take long showers.) the shower bilge will eventually fill up and dump into the main bilge, which you DONT want , as all the shower debris/hair will eventually clog the filter of the main bilge pump.. the head sink and galley sink both have OEM seacocks on their thruhulls to shut off to avoid siphoning water into the sinks if the rail is buried (which is unlikely the way we sail..) however a friend nearly lost his classic 40 ft wooden boat from siphoning: a new sink was installed portside in the galley, with its drain exiting via throughhull a few inches above waterline. (no swan's neck possible in a sink drain as it would not gravity-drain.) when in heavy weather he buried the portside rail, the sink thruhull was submerged. water siphoned into his boat thru the galley sink drain ...by the time he noticed it there was a foot of h 2 0 over the floorboards. )

for the main bilge: 2 pumps, one a secondary shurflo and one a primary parjabsco belt drive. on 2 different 12 v circuits via house battery # 2 and house #3. output hoses swannecked high above water line to thruhulls . the parjabsco has the advantage of removing almost all of the water from the lines, with hardly any drain back. the shurflo has a lot of drain back, that is why it is the secondary backup bilge pump. primary is fitted with a pump cycle counter , and a bilge 'highwater ' alarm, audible in cockpit. (the highwater alarm is triggered by a higher float switch than the one on the primary bilge pump.

also a manual whalegusher pump OEM , operable from cockpit, and a portable whalegusher on a carrying board, operable from any where...

 

[Heckler]

Easiest solution for preventing oily waste being discharged is to use a polypropylene oil absorbent pad in the engine bilge area.

Otherwise known as Pampers?
Stu

 

[Deleted member 36384]

Otherwise known as Pampers?
Stu

Dont do what I did and throw the nappy into the bilge and forget it. Some time later I went to retrieve it and it disintegrated; what a mess!

 

[Seajet]

Skipper Stu,

I think these oil absorbing things are different; after all it's another chance to write 'special marine' on something and wind up the price !

 

[Deleted member 36384]

.... oil absorbing things are different; after all it's another chance to write 'special marine' on something and wind up the price !

http://www.asap-supplies.com/green/cleenlife-prime-range/cleenlife-prime-bilge-socks-311701

About £5 and quite effective.

 

[Billjratt]

How's about tieing up the pamper in an old sock?
Do pampers really work as well as bilge-hogs?

 

[pvb]

Otherwise known as Pampers?
Stu

Absolutely not! Oil absorbent pads are made from polypropylene, which absorbs oil but rejects water (totally unlike Pampers!). They can be squeezed out and re-used, but it's a bit messy.

A few years ago, a neighbour's oil tank leaked about 1000 litres of heating oil into the ground, and a lot ended up in one of our ditches. The Environment Agency came along with big sheets of oil-absorbing polypropylene and floated it on top of the water in the ditch, to absorb the oil. Hugely effective.

 

[Bobobolinsky]

I can't just pump the engine bilge, so I have a sump tray under the engine ala BSC

 

[prv]

Oil absorbent pads are made from polypropylene, which absorbs oil but rejects water

So a use for manky old blue polyprop rope?

Need a modern-day version of Victorian oakum-picking orphans to unravel it into strands for maximum surface area, I guess

Pete

 

[Wakatere]

Thanks All,

I don't have a shower so bits of crew in the heads bilge isn't a problem. Apart from the toilet (had the pump and tank out last weekend - oh ****!) the water here comes from the chain pipe if there's water on the foredeck. This is just when a pump outlet might be submerged, so would a pump cope with that?

Comments noted about the engine bilge (in particular not using automatic pumps). I'd forgotten about the existence of oil-absorbent pads - I'll put them on the shoppping list.

All of this seems secondary to the big fat pump in the main sump - perhaps I'd better get that done first.

Regards
Charles

 

[chrishelen]

Wakatere currently has a single maunal bilge pump and I'd like to add electric pump(s). The heads bilge forward and the engine bilge aft (surprise) are separate from the main bilge for small amounts of water. I had thought to have small pumps draining the small areas into the main bilges and then a larger one to evacuate that. This would only require one additional hole in the hull, but it seems a pity to have any pump not contributing to shifting water out of the boat in an emergency.

Any advice?

beware of what is says on the box I.E "1500 gallons a hour" thats in a horizontal straight line, there is a, or should be a little graph in the instruction blurb giving you a read out of "height of head" so if your discharge is higher than the pump its performance will be affected accordingly.

 

[Colvic Watson]

Thanks All,

the water here comes from the chain pipe if there's water on the foredeck. This is just when a pump outlet might be submerged, so would a pump cope with that?

This will create a large back pressure on the pump and make it much more difficult to pump out the bilge. Small 12v pumps are low power and can cope with only fairly small heads of water never mind a submerged outlet which may be heeled a further 2 feet under on the wrong tack.