Fouled prop Gah!

[Brentwales]

Following my last post about flat batteries, now sorted that.

My prop is now fouled. I'm on a tidal river, couldn't pull the rope free so in the water I went and cut a long trailing line free but the ebb current was too strong and holding my breath after numerous attempts I had to call it a day. Engine running and goes into forward and reverse with no issues and took it up to 3000rpm but no wash from the back either in forward or reverse.

No loud clunks or bangs or struggling from the engine at any point.

Would rope still around the shaft result in no power through the prop at 3000rpm either in reverse or forward?

I'm either going to get a tow to our clubs drying posts or considering buying a telescopic saw to see if I can cut the remains from the tender, anyone tried that?

 

[pete]

Is the shaft spinning /slipping in the coupling behind the gearbox?

 

[Brentwales]

It did look like the shaft was spinning, no slippage at around 2000rpm

 

[pete]

If the shaft is turning it could have sheared the key on the shaft to prop taper but that's more unlikely unless it wasn't a good fit on the taper in the first place . If you are lucky it may just have stopped the wash from the propeller by the rope being wrapped around the blades.

 

[Brentwales]

Thanks, sounds like best course of action is to get her on the drying posts for a good look over.

 

[Tintin]

And before you do that, just make sure you have a prop there still - waterproof gopro copy on a pole works well. Just double check after running it after you last saw it.

 

[Neeves]

If your prop is secured with a castellated nut and a cotter pin my vote is a lost prop. When you caught the rope and then removed the rope the cotter pin failed and then worked its self off. If this is the case the prop is roughly where you tried to run the engine - hopefully where you are now. So don't move the boat - until you find out if you have lost the prop. If you don't have access too a cheap go-pro, and the water is too murky to see anything, you should be able to 'feel' a prop, on the shaft, with a broom handle (or long pole - if your yacht is 'bigger').

Jonathan

Good luck

 

[peter gibbs]

If you've run up to 3000 revs with no outboard effect, and thee prop shaft viewing internally is rotating, it's definitely nothing to do with inboard mechanics. The prop is no longer present. If it's valuable it may pay to have a diver look for it, otherwise a haul ashore and a new prop (£200 basic 3 blade alu?) is your least cost recovery plan

Rotten luck - my sympathies.

PWG

 

[Brentwales]

It's strange as before I went under the boat I was putting it in forward and reverse and the long line in the prop was being pulled and twisted. When I went in the water there was zero visibility and I could definitely feel the prop.

Would sufficient rope still around the shaft affect the propellors ability to pull water over it which would reduce the visible wash?

 

[duncan99210]

If the rope is wrapped round the prop in sufficient quantity, it will stop the prop working. So if you can still feel the prop there are two possibilities. One is that the rope is preventing water from getting to the blades, stopping it working, although the prop is still turning with the shaft.
Second is that the prop is still in place on the shaft but the key between it and the prop is broken, allowing the shaft to turn and the prop to remain still.

 

[anoccasionalyachtsman]

It's strange as before I went under the boat I was putting it in forward and reverse and the long line in the prop was being pulled and twisted. When I went in the water there was zero visibility and I could definitely feel the prop.

Would sufficient rope still around the shaft affect the propellors ability to pull water over it which would reduce the visible wash?

Definitely. The hardest prop to turn is a clean one.