correct bilge pump installation

[Guest]

I have a good Henderson Mk 5 bilge pump which I would like to fit to my 25ft boat. If I mount the pump in the starboard cockpit locker can I run the outlet through the starboard side of the boat? I cannot site the (nylon)fitting higher than 15 inches above the waterline, this means about 6 inches below the rail so the fitting will occasionally be submerged. Failing this I would have to run the pipe through 2 bulkheads to the stern and even then it looks mighty inaccessible. The boat has an outboard and the bilges are very dry, the pump is therefore for emergencies only. The lockers drain into the cockpit which is itself provided with 2 drains. What is the correct way to fit a pump like this?
Thanks in advance for replies.

 

[Mirelle]

Good question.

1. The pedantic answer is "with a seacock in the topsides" not just a nylon skin fitting, but this is expensive.

2. An answer which purists dislike is "arrange the pump discharge into the cockpit". This is not approved of because "if the leak is due to a cractured cockpit drain then where are you?", but frankly the answer would be "stuff a tapered softwood plug in" wherever the pump was sited and the other drain would still work.

My boat was thus fitted from 1937 to 1985, during which time she did not sink!

It does make a mess of the cockpit sole if the bilges are dirty, but if yours arte clean, why worry?

3. I have to confess that I have a dayboat / launch with the bilge pump mounted just as you describe and I have never been much worried about it - after all, to flood the bilge the sea has got to get past two flap valves. Maybe put a Whale nonreturn valve in the line as well - that would make three valves to get past.

My advice would be try (2).

 

[Johnjo]

I too have a large Henderson pump in the cabin, which discharges into the cockpit in the stern of the boat, also have two smaller pumps installed
in each of the stern lockers,both of which discharge into the cockpit,
on the engine it's self I have large Jabsco clutch driven pump fitted with
a diverter so it sucks bilge or sea water, can connect hose to it for
washing topsides down,also discharges into the cockpit,shifts an awful lot of water in no time at all,The only time the hand pumps get any use is when the
suctions get put in a bucket of water to test and flush them through,
As a surveyer said " need one hell of a hole to sink" but made no comment
on the siting of them,to be honest have never given them any thought myself,
as the man said "if it's not broke don't fix it"
cheers
mike

 

[alanporter]

My bilge pump outlet is three inches above the water line on the side of my sailboat. Even the slightest heel puts it under water. However I have looped the hose upward above the water line and fitted a one-way valve. The boat is 26 years old and this sysyem has never given the slightest problem

Alan Porter

 

[LadyInBed]

Could the outlet be mounted near centre on the stern. That would stop most of the heeling problems.

 

[johnt]

id like to make a few points

if its a manual pump ..it aint gonna save the boat !..and that surveyor was DEAD wrong !..all it will take is a hole 1inch in diameter!

the electric pump people tried it with a 38footer a few years ago ..they took out the log impellor and waited to see what happened ..water ingress overtook 5 large electic pumps!..........soooooooo.......the only pump that MIGHT save your boat is on the rescue boat ......maybe!

the reccommended place to put a pump outlet is low ,centre transom , with the actual pump as high in the cockpit as you can get it ...it should provide an airbreak automatically

and for anyone who's boat floods when heeled ..service your pump and change the non return valves !

you could also double up , with an electric pump in the bilges feeding through the manual pump .... mine works perfectly

and before anyone starts arguing about putting the outlet high .. a high outlet can loose up to a third of the flow volume !

 

[petery]

\'Doubling ip\'

interested in your 'doubling up'.

Do you just connect the electric pump in series with the hand pump? Will they still each work independently? Do both have to be diaphragm pumps?

 

[Johnjo]

Agree with you entirely.
surveyer made comment tongue in cheek,due to the number of pumps on board
and the pumping capacityof the large Jabsco which drives off the main engine
via a clutch, has a 2" suction and delivery, not sure of the G.P.H BUT
is considerable, hope this explains!