prop rope cutters

[jason -and the arguenauts]

Thinking of buying one and I had always mentally dismissed the circular disc ones as a cheepo alternative of doubtful worth, but watching the MBM test of cutters ( http://www.mbmclub.com/mbm/video/tested/rope-cutters.html ) it seemed almost as if they worked better than the scissor type.

Particularly interesting since my boat doesnt have a P bracket but a short length of thin walled grp tube to which half the scissor type would be attached. Worry is - hit a wire rope and either the engine stalls or the stern tube breaks free and rotates. Glug, glug!

Any practical expewriences or comments?

 

[pappaecho]

Bought boat with Spurs cutter fitted in 1991. In 2005 engine stopped off Cowes for no reason, and found fishermans rope round the prop. Pulled the free end and the engine started OK.
In early 2006 hauled boat ashore for annual careen and found half the cutter missing. Got spares from supplier in Yarmouth IOW cheaply, so obviously the cutter did its job

 

[PetiteFleur]

I fitted an Ambassador Stripper when I re-engined and it worked a few weeks ago - my genoa sheet is now 2 metres shorter! (the engine was idling in gear and it did stop the engine but restarted OK) Highly recommended.

 

[MoodySabre]

I have an Ambassador too and on lift out found strands of polyprop there but the cutter still operational. I would imagine that there would be considerable forces applied to the fixed part with thick rope or netting let alone wire. I wouldn't want those forces applied to a vulnerable area like you describe. A circular one would overcome that and is certainly an improvement on nothing.

 

[Anonymous]

Thinking of buying one and I had always mentally dismissed the circular disc ones as a cheepo alternative of doubtful worth, but watching the MBM test of cutters ( http://www.mbmclub.com/mbm/video/tested/rope-cutters.html ) it seemed almost as if they worked better than the scissor type.

Any practical expewriences or comments?

We've done a lot of miles and had one fouled prop not dealt with by the disc cutter. But how many times was it called into duty? I can't say though we do a lot of night sailing and bad viz sailing.

From all I have heard here on these forums and seen for myself over-winters looking at yachts on the hard, I would only have a disc. The other bits of kit are smart and no doubt effective when they work but one really big rope and you have serious trouble, I suspect. Most non-disc cutters, on yachts on the hard, are defunct. Part of them is missing or bent. When did you ever hear of someone with a disc cutter asking how to repair it?

QED?

 

[ChrisE]

Oh what a load of cobblers, with all due respect, we have a stripper, the scissor type. It has successfully dealt with quite a few bits of rope over 15 years. I don't know how big the bits of rope it has cut but in over 40k miles no probs.

This could easily turn into another anchor/engine/boat/etc type of debate

 

[Neil_Y]

As the MBM test involved fixing one end of quite a short piece of debris at the bearing carrier end, it never tested what would happen if a rope was caught by a prop blade and was revolving with the prop and shaft and wrapping around the shaft between prop and stern tube/P bracket.

By fixing one end at the bearing the rope/debris was drawn tight across the disc cutter/scissor cutter but it was also fixed relative to the spinning blades of the disc or scissor cutter.

With a stern tube this is never likely to be the situation, and even with a P bracket it is more likely the prop blade will catch the rope/debris than the P bracket.

When a rope is caught by the prop, it will be rotating with the shaft and will wrap around the shaft between the prop and the bearing, gradually building up pressure between the two, and this was never tested.

The shaver cutter is designed to deal with just such a situation, and that is why it is used by many fishermen the RNLI.

One broken in use in the UK in four years and many happy fishermen.

Many fitted to stern grp stern rubes (including the latest RNLI Tamar class) no stern tubes damaged. If you think about it, this part of the boat is subjected to huge forces if there is no rope cutter and rope winds in the gap. The force can remove th gearbox from the engine so this part of the boat is quite strong.

 

[jason -and the arguenauts]

which type do you mean by "shaver cutter" ?

P.S. I have a beard

 

[Tranona]

Thinking of buying one and I had always mentally dismissed the circular disc ones as a cheepo alternative of doubtful worth, but watching the MBM test of cutters ( http://www.mbmclub.com/mbm/video/tested/rope-cutters.html ) it seemed almost as if they worked better than the scissor type.

Particularly interesting since my boat doesnt have a P bracket but a short length of thin walled grp tube to which half the scissor type would be attached. Worry is - hit a wire rope and either the engine stalls or the stern tube breaks free and rotates. Glug, glug!

Any practical expewriences or comments?

You can get a kit to clamp the fixed cutter block to the stern tube, so that is no problem. Suggest you geet on the websites of the suppliers and get more information.

 

[Neil_Y]

It's brand name is the quicKutter™

But as it is a fixed blade and the debris is turning and being forced into it it shaves through rather than trying to cut the whole rope in one go. Much as a lathe tool can cut thick metal with gentle pressure.

 

[saxonpirate]

Like so many things "sailing" there are many differing opinions based on experiences. On my own boat a First 35 I have fitted a circular cutter after a particularly nasty incident with the original scissor type cutter. I picked up a rope which nearly ripped the P bracket out of the boat. Now this could have been a one off experience, but it was enough for me to change to the circular design. I'm sure they both have their benefits/faults although after my little drama I'm plumping for my circular cutter, which incidentally has nicely sliced through a piece of 6mm fishing net.

http://www.carpentersw.com

 

[Gypsyjoss]

1st season with a boat with a Spur cutter. Managed to cleanly sever my own 12mm kedge line and on another occasion a 6mm marker buoy line. Yes, I did manage to retrieve my kedge from the harbour floor! Can't comment on the pros and cons of the various types, but I guess you're looking for a cutter that will work quickly before too much line gets wound around the prop shaft. The Spur cutter was certainly quick! I don't know if a disc cutter is as effective.