What a load of bilge?

[Hippohay]

I want to fit an electric bilge pump to our Moody 38. Moody recommends a Rule 2000. 2,000 gallons per hour! I know size matters, but OK or overkill?

 

[steverow]

You should really have two electric automatic switching bilge pumps on a boat this size, one backing up the other, and on different fuses and if possible primary circuits, both with manual override switches.
Personally I'd be inclined to fit two slightly smaller units, one with a built in auto float switch, and one with an external float switch at a slightly higher level.

Steve.

 

[Aja]

Depends on the size of hole. The bigger the better - how long before your batteries get flooded?

Donald

 

[bdsweeting]

Remember that the flow rates quoted are often for a very low level of lift. If you have a deep bilge then the flow rate will drop.

 

[Hippohay]

Well, thinking a hole somewhat seacock-sized. Not expecting to pump out a rock-sized hole from leaving my girlfriend on the wheel for a few minutes...
Hadn't considered having two electric pumps..

 

[cliff]

It was once said that the best bilge pump was "a frightened man with a bucket" personally I would fit two or three just in case - even a small hole can let in a lot of water.
--------------------

"Artificial intelligence is no match for natural stupidity"

 

[Lakesailor]

2000 gallons an hour is only 3.3gallons a minute. About half what a decent domestic cold water tap will deliver. Or about a quarter of the frightened man with a bucket.

 

[Hippohay]

OK - so I'm the frightened guy with one bucket and 15 bilge pumps... ?
Probably not - but maybe two electric and the existing manual?

 

[DavidGrieves]

Hi

Try this out:

2/3 x d squared x square route of P = Litres per min

d= dia of hole (mm)
P=pressure (bar)

So a hole of 38mm (heads skin fitting) and a pressure of 0.1 bar ( .1 if hole is 1m below water line).
2 x 1444 x .3162 divide by 3 = 304 lpm
Thats about 300lpm x 60 =18000 lph or 4000gallon per hour
Hmmm... I'm going to fit another pump...

 

[damo]

Better memorise the existing manual now - you may be too busy to read it when you need it for real /forums/images/graemlins/grin.gif

 

[Sui Generis]

May I suggest you consider ways of blocking the potential hole - may be more effective?

A 1" hole 2 ft below the water line will let in far more water than I can ever pump out, but a spare dirty seaboot sock in the right place might do the biz?

Just a thought

 

[Guest]

Blocking holes ....

As GRP tends to split and not make neat holes ..... best to gag a leak is a bin-liner with a rope on each corner .... drag it over bow and under boat ... water pressure holds it into hole.

It is what is termed : Collision Mat. It is the best tool when salvaging boats that sink on moorings .... that and air-bags to fill interior etc.

 

[duncanmack]

Phil,
I know that the Lake District is a world apart, but as far as I recall the normal rules of arithmetic apply even there.
2000 gallons/hour =33.33 gallons/minute. Your calculator got the decimal place wrong.

 

[Talbot]

33.3 gallons a minute - damm thats a lot of buckets, you had better be really frightened to keep up that rate!

 

[kengill]

Where do you fit three buckets operationally?

 

[Hippohay]

Right. Looks like a permanent berth in the dry dock is the way to go. No buckets. No nasty, cold water for us.
Ta all...

 

[pappaecho]

Also have a supply of different sizes of wooden pegs to drive into the hole when it leaks - remember that the bilge pumps must keep you afloat whilst you the spile the hole....

The fact that hole is totally inaccesible, means that with luck you can keep dry long enough for the RNLI to rescue you