Installing big pump to deal with large boat leaks

[Refueler]

The best way to stop the boat filling up with water and sinking - strong bin liners outside hull hung by ropes from either side to block of the hole. Once in place you can slowly move under power.
Even big ships carry Collision mats as they are called, but made of strong canvas and other materials to take the greater pressures.

As you have found - the water coming in is at such speed and force that a suitable pump would be huge and power req'ts unreal.

 

[Seanick]

Fair enough! We have a 2" manual pump, with a 5' handle.Three stokes fills a large bucket.

Our main 'oh sxxt' modification is an extension to the air inlet of the engine. This brings it right up under the coachroof. The idea is that the main engine will continue to run for as long as poss as one motors hard for shallow water.

We also have 3 flotation bags with two Co2 cylinders to fit under the fore and aft decks. They are American and come off a transat wooden boat that was a bit leaky!

We have (albit partially completed) a collision bulkhead fwd.

Our final defence against holing is a selection of sails to cover a hole and a pile of timber and tools.

We don't carry a liferaft but we do carry a small Rib and an inflateable.

I think any petrol pump would have to be run up ever few months to check its ok. The spate pumps are buggers to prime too. Any electric pump would have to be run by a battery bank placed high up above the estimated flood line.

With regard to the Y peice for the engine inlet, Stuart Turners had this bilge pump option 50 odd years ago. On a larger engine it would need a very very large filter/stum box for obvious reasons.

After many years building the boat I am keen to keep it afloat. I suppose the advantage of a production crusier is one can claim on the insurance and buy another of the peg, if you live.
I could not find another 7 years of spare time to rebuild this one again!

 

[jfm]

Hmm that's a good point. Yep, need a bit of sunbrella canvas stuff, a metre square (plus another 2mx 1m perhaps) with eyelets all round, to lash over the hole. The pumps alone isn't a good enough answer. Will get on the casse with that!

 

[Refueler]

When you put over the bow ... people either side tending the lines and walking it back .. once you get to hole area you pull in lines so water flow 'sucks' the liner against hull. Tie off and water pressure will keep it hard up on the hull. Done well you will find that water coming in may stop completely. Motor carefully and away you go to beach her.

I used to salvage boats like that ... boats left to sink at tidal moorings, up rivers etc. We'd "bag'em" and then pump like mad before tide came back. Bin liners would prevent water getting back in .. we'd bring them to slip.

 

[Deleted User YDKXO]

I dunno, I leave petrol in my lawn mower for months on end and I always seem to start the thing eventually. I find a good dose of swearing always helps to fire the thing up /forums/images/graemlins/smile.gif

 

[MedDreamer]

I don't have a problem with my lawnmower either Mike but the outboard on the boat is a different matter. If I leave petrol in for a few months - especially over winter - it goes stale and the engine won't start. Not something you would want if you were depending on it to get you out of a sticky situation.

 

[hlb]

And my 20? year old 2T outboard starts every time, second pull, no service for the passed 8 years. I keep hopeing it will pack in, then I can have a new one. No such luck. /forums/images/graemlins/frown.gif

 

[Deleted User YDKXO]

You should get yourself a Johnson o/b, Meddy. Mine always starts after a few months inactivity and it's even survived a couple of tankfulls of fuel without oil (it's a 2 stroke)

 

[MedDreamer]

Honda 4 stroke, reliable (touch wood) but noisy and a bugger to start when its been left for a while.

Bit like SWMBO really!!!!!!!!!!!!!!!!!!!!!!!!!! /forums/images/graemlins/blush.gif

 

[Refueler]

I have a genny - Wolf 700 that is reluctant on fresh, old no matter what juice I throw at it. So answer is plug out, shot of petrol in plug-hole ... plug back in ... pull and away she goes.

Particularly with 2st's - I'm told is dry crankcases and lack of 'pull' on the carb at low revs of starting. Right or wrong I dunno - but the remedy shown me works.

 

[WindermereColvic]

Takeing the engine air intake above the flood line sound like a good idea, but wouldyou have crankcase breathers ect to worry about? or would it survive with them submerged???

 

[oceandrive]

JFM.
Just returned after five days at the boat show. and spent two of those days with with the top guys in the build team. ( I will be polite and not name them) We have discussed this topic at great length. covering all the options so far discussed. It would seem that there is no real reason why your origional idea of the machine mart pump would not work.

However the y valves pre strainers option seems to be confirmed as great as an additional last resort but not such a good idea as a definate solution to a 3" hole. I think we had already determined within the forum, not enough GPH to realy keep you going. So I retract my origional thoughts.

However the marine sea water fire hydrant with a y valve to a strum box all seem to think is a good idea. As you have the fire hydrant for its designed use Putting out a fire and at the flip of a y valve you have draw from the engine room. I cant see that this option is much more expensive than the pump at the top of the thread.
As the fire hydrant will throw a 2.5" torrent of water 30' then I recon it will have the GPH required ( Not worked it out)
Another point raised in this sometimes horrble world we live in you have a powerfull water cannon as legal defence against pirates, or being boarded by any unwanted visitors. Splat /forums/images/graemlins/shocked.gif so you have a three in one system fire, bilge and defence.

Hydrant hose to be fitted under seat in cockpit with draw from sea and y valve to engine room draw.

 

[ADLS]

Why not just buy a submersable type pump then you can drop it in where ever needed, just make sure you have a long enough lead to reach all compartments.

A friend dropped his wooden boat back in after 8 month ashore, she took on a lot of wet stuff but the bilge pumps were able to control. But after an evening ashore he came back to water lapping the floor boards, one pump had blocked with debri even though he was very carefull to clean up after doing jobs aboard. As we were on shore power he just dropped his submersable in the bilge and 10 mins later all was good. he could have powered it with onboard power if needed.

another way is to install a Y branch and valves in the raw water intake system so that the enines power or genny take cooling water from the bilge and aid the bilge pumps.

 

[jfm]

Sounds good. Seems Sunseeker agree the general premise that some big pumps could be good idea. And fit the Y valves, as they are easy extra pumping, and even if not capable of keeping up with a 3inch hole they'll make a contribution. Si I'm virtually mind made up to go with a couple of Machine Mart submersibles 230v plus a sunbrella sheet 2mx1m with eyelets to block off the hole.

Ref your mention of hydrant, I'm not clear what product this is. Does it have a built in pump of its own, or what?