Rope cutters - any use?

DrBob

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Apologies if this has been discussed to death before - but the search engine is slow here today.

I am soon to take delivery of a new 40 footer. Is it worth putting a rope cutter on the prop - bearing in mind it is a sail drive and I will be doing some racing as well as cruising. Do these cutters work?

Dr Bob
 

BlueSkyNick

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Not sure if the sail drive makes any difference because I haven't got one. On a standard direct drive, the effect on racing performance will be negigible, if not zero.

So on the basis there a no disadvantages, I prefer to have a rope cutter in the hope that it will work when needed rather not have one at all.
 

TigaWave

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When you hear the number of horror stories that we do being in the rope cutter business, then it would seem a wise precaution. Its not the chance of getting a rope which is kind of slim, its the potential damage they can cause. For sail drives they are particularly vulnerable to fishing line which can damage the oil seal in the leg. Shaft drives your likely to end up with bent P bracket or shafts, or the worst case so far was the gearbox pulled off a large engine. My last boat had a sail drive and it caught rubbish which prevented the folding prop unfolding just as I went to go astern....crunch (almost)
 

roger

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Yes - probably

I replied once to a thread on this topic saying that in Channel cruising a rope seemed to happen once in 10000 miles.
I now have a Stripper. I've sailed a few thousand miles with it and not apparently had a problem BUT when I hauled out last Autumn I found an interesting rub mark at the root of the prop. It looked as if I had had something round the prop but it had disappeared.
That is the trouble. If your cutter works you may not know. If it doesnt you will. Its the wrong market to be in. Now liferaft servicing is the opposite!
 

kandoma

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9 out of 10 times, I had my own line around the propeller. No linecutter for me, ever. A divemask saves the day.

I know, everybody else has never wrapped his own anchor line around the prop. Its just me. If the gearbox gets ripped off, it was high time to replace it anyway.
FUD = Fear, Uncertainty, Desinformation = business

Peter
 

Ifraser

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we have rope cutters on our 38' workboat which is used almost daily...she is lifted every 6 months and it is unusual not to find some eveidence that they have done there job ie a few tell tale strands caught on the cutters.....I think rope cutters are an absolute boon on anything that you can't get to the props of....how it will affect performance while sailing I've no idea....Iain
 

eyehavit

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Sometimes, diving over the side to cut propeller-entangled rope is not convenient and can even be downright dangerous. Where this is definitely not nor never ever going to be the case it does seem pointless to fit a rope cutter.
In my line of business I see first-hand what can happen when rope or line is caught by a propeller.
Let me assure you that synthetic line material such as polypropylene rope as well as nylon line, in particular commercial fishing long-line complete with metal hooks and swivels can get caught and tight-wound to the shaft by the propeller. Despite that this occurs underwater, rope & line, hard-turned against the bearing carrier by a powerful engine generate intense heat. The temperature can quickly rise to a point where the line material melts and extrudes into the lubrication grooves. The localised temperature of the propeller shaft can rise significantly and being a good heat conductor, together with friction-generated heat, fuse innermost closely wound coils into solid plastic. Removal underwater is therefore extremely difficult if not impossible. The effect of melted plastic in respect to the aft bearing is to deny it lubricant. The bearing will either seize on the shaft or disintegrate. Either way it will require replacing. A well designed rope cutter eliminates this problem.
 

DrBob

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Guys,

thanks for the inputs. Sounds like it will be beneficial to have one as diving overboard wont always be easy and safe. I'll go and have a look around the internet to look at the options. Any more comments on which rope cutter to buy (Spurs and Stripper mentioned).

Plan is to put it on with a Gori 3 blade folding prop.

Dr Bob
 

Shanty

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Current boat had one of the disc type fitted when I bought her. The only thing it managed to cut was me. It was a positive hazard when trying to remove a rope that it had failed to even mark.

It has been replaced by a Stripper. No problems since.

As others have said, go for the Stripper, or Spurs type. Ignore the disc type.
 

Santana379

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My disc rope cutter works brilliantly - when I forgot I had the dinghy attached by a long painter when using reverse to slow down for a mooring, it duly set it free.

I wonder if it was helped by both ends of the warp being attached to something - not unlike taught string being easier to cut with scissors.

I have found evidence of other cut rope on lift out though.

As our prop is accessible without full personal immersion - we carry a strong serrated bread knife to tape and lash to the boathook. We also keep a mask and snorkel aboard for a better view from the surface when hanging out of the Avon.

Francis Fletcher
 

nmelton

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If you go to the Ambassador Marine web site there is a link to an item written in Sailing Today. The article compared most of the types on offer and suggested that the Stripper came out tops.

I certainly would go along with the suggestion that the Stripper or Spurs are the most effective and robust. I believe that the RNLI fitted the Spurs to their boats.

As a result of a friends experience I decided to go for the Stripper and, touching a large bit of wood, have had no problems. Once or twice whilst motoring I have heard the engine 'cough' only to see rubbish in the wake. Similarly, after lift out, I have often found the remains of various sorts of plastic rope. Fitting one may seem pricy but I see it as an insurance!

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eyehavit

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Spurs & Stripper are mentioned above and rely on a scissor cutting action. Disc cutters are also mentioned and they rely on a circular spinning knife action. What is not mentioned is a completely new sleek design that works by rapidly shaving off debris. The RNLI is trialling this design on its latest vessel.
Without doubt worth a look.
http://www.h4marine.com/Rope%20Cutter.htm
 

PaulR

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hope so!
just fitted spurs today before relaunch on friday- got fouled prop last year sailing in chichester harbour and finally had to have tow in to portsmouth harbour rather than wait for ebb to slow down - decided then that once too often ( totting up have had something round prop probably 5 times over past 10 years - lost a blade from prop once and had to be lifted out to clear another time) so hoping that spurs do the business,

only grouse is that i hadn't realised quite how hard it is to drill through a stainless steel p bracket- finally finished it today but not as easy as fitting instructions suggested!
 

VicMallows

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I'm sure you'll be very happy with the Spurs; before fitting mine (Stripper), had to go over the side several times in mid-channel (securely attached)......it's a strange experience the first time you do it, for no logical reason!. Fitted one because going through the French Canals, and didn't fancy going in the water there!!

I'm intrigued by your stainless P-Bracket though? ... never heard of one before, and conventional wisdom suggests it is wrong. However, have had to replace a supposedly bronze one due to dezincification, although also discovered it had never been electrically bonded to anything.

Vic
 
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