Raw Water pump failure

[BobFord]

I recently destroyed the water pump">raw water pump that services a Mase I S 11.2 generator. The drive engine is Yanmar 3TNV.
The problem was caused by a blocked raw water intake but was exacerbated because the auto overheating cutout activates well after the water stops. Hence , the pump is well ' cooked '.
The blockage was caused by a jelly fish . The large , soft ,blue type.
I have considered installing a parallel r/water intake , linked to the main intake.

Ideas and suggestions would be welcome.

[barnaclejim]

As long as your intake is sized correctly I would be hesitant to punch another hole in the hull. How about a bigger sea strainer.

[BobFord]

Hi Barnaclejim, I should have mentioned that the jelly fish , and the area i'm in , Moreton Bay ,is currently plagued by them, measures up to 300mm in dia. and is roughly sphere shaped. The blighter must have been suctioned to the inlet ! After fitting a recon pump, the blockage repeated within a short time.I was able to manually close down ! Eventually, was obliged to sail 20 nm to clear ,clean water as the boat was desperate for power and water !

[a64pilot]

How about an alarm that senses water flow instead?

[model 10]

Face it, you are going through a bad spell. There is a flow sensor for not much $$ and you have a temp alarm right?

[rwidman]

The water pump failed or just the impeller?

As others have suggested, you can install a water flow alarm. Problem is, next time something else bad will happen.

[boatpoker]

Aqualarm.net

Raw water flow detector/alarm sounds alarm the instant water flow is restricted.
Should be mandatory equipment on all boats.

[JK n Smitty]

Originally Posted by boatpoker

Aqualarm.net

Raw water flow detector/alarm sounds alarm the instant water flow is restricted.
Should be mandatory equipment on all boats.

Great link. Thanks

[cwyckham]

How did this cook the pump? Shouldn't it just have chewed up the impeller?

[BobFord]

I much appreciate feedback on pump problem. Clearly,the flow failure alarm is a positive solution because it will activate well ahead of the engine auto-cutout. It seems that an impeller has a life of less than 30 secs. without water, before disintegrating ! Cheers, Bob