Rope Cutters

[Jerbro]

Do they work? Are they hassle to fit? Any views welcome as I may be moving to a shaft driven boat and will miss being able to raise the outdrive leg to get the rope off!

<hr width=100% size=1>Jerbro
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Click here for <A target="_blank" HREF=http://www.jerbro.btinternet.co.uk> My ex-boat pics</A>

 

[Moose]

I've got rope cutters and I have never driven over a rope, So yeah they really work!!!/forums/images/icons/laugh.gif
I wonder if that helps at all /forums/images/icons/wink.gif

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Moose

 

[hlb]

Thing is. You dont need rope cutters untill you need rope cutters. I went through a period when I was chomping through ropes nearly every trip. Dont remember hiting any ropes in the last two years. But then I wouldnt, would I, cos I've got rope cutters.

Yes. They do work.

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Haydn

 

[Guest]

Rope cutters are one of the best investments I have made with my boat.I had three seperate incidents with ropes around props on my last visit to the C.I.I already had small cutting discs on the props but these were nowhere near man enough for the kind of thick knotted stuff in the channel.I have now had a pair of strippers fitted on the shafts and know I have cut at least 4 obstacles from the props since. You know when something is around the gear as you still feel the jolt of the wrap round and engines still cut out but usually on restart they cut into the rope and feel the release of the obstruction and often see it pop up from the transom.They are not difficult to fit and most shaft sizes etc are catered for by the manufactrs.

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[Deleted User YDKXO]

This is a difficult one because there's two schools of thought. This is only a personal view but I dont think the cost (could be several hundred pounds) and, in most cases, the loss of speed (upto 3 knots on one of my boats) is worth the extra security. Some people also think that, if the cutters dont remove the obstruction, then they just make the entanglement worse as it then becomes more difficult to free the obstruction. I also think that on a twin engined boat, you'd have to be very unlucky to have both props disabled completely so the likelihood is that you'd still be able to make port at displacement speed
On the other hand, some people swear by their rope cutters and I respect their opinion


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[adarcy]

Re: Horses for courses

We (rather obviously) didn't bother when we had a sterndrive boat - once caught a v large bright orange ! plastic sack on our sterndrive but it floated off when we pumped the leg up. When we got a shaft drive we worried for a year and then got strippers and have certainly chopped at least 2 ropes that we know of and maybe many others. Loss of speed approx 1 kt but who drives reqlly Harry Flatters much so it is really just a bit of extra diesel versus safety.

Deleted User - surely the concern is when one comes to a halt to check it is a rope problem that the risk of the idling prop will catch on the flailing ends of the rope occurs - whilst limping home it will stream out behind. Anyway, it would be red face and ? bent shaft time......

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[Deleted User YDKXO]

Re: Horses for courses

There's arguments on both sides. All I know is that my previous boat (a Broom) gained 3 knots when the cutters were removed which is quite significant in terms of fuel consumption - about 15% in my case. As far as disabling both props is concerned, in my experience, any rope or netting tends to wind itself into a tight ball very quickly although I do agree there is always a danger of bending a shaft if both props are obstructed

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[adarcy]

Re: Horses for courses

Yes I seem to remember the contributor to MBY reckoned they knocked 2kt off his self finished Bennett 50 or 53.
I believe it can depend on the alignment of the cutters are in relation to the prop blades. Seem to remember they should in line with the middle of the blade areas, ours are. Can you remember where your's were ?

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[Deleted User YDKXO]

Re: Horses for courses

Thats a good point about alignment with the prop blades. I've not heard that before but it might help. In my case, I cant remember at all how they were aligned

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[hlb]

Re: Horses for courses

Each blade should fit behind the prop blades. Since I now have a four blade prop and the old three blade cutter. This is difficult to achive!! However I am informed that four blade rope cutters do not exist......./forums/images/icons/frown.gif

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Haydn

 

[Guest]

Thoughts:

Bad news: loss of 2 to 2.5 knots. Am told it also makes the water flow/props less efficient so cruising is also less economical. Doubt whether its proportional to loss of top speed, but could be say 5-7%.

Good news: Have definitely used them 3 times in first year. First sign is vibration. Cut engines. Gentle use of reverse, forward and vice versa has resulted in shreds of nylon robe regurgitated from under transom. Very comforting mid channel how ever many engines! Smiles and sounds of relief from family worth cost imho

John Rob

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[Guest]

Re: Horses for courses

Just a suggestion Haydn, but you may find it more effective to fit the cutters IN FRONT of the prop blades................. <falls of chair laughing>

I'm sorry about that Haydn, I couldn't resist it, humble apologies. I'll buy you a pint. Friends again?

I have Ambassador 2 blade cutters fitted in front of my 4-bladed props. I thought they did make a 4-blade cutter, but I'm not sure. I've never had the opportunity to carry out a genuinely comparative test, but I reckon mine take practically nothing off the top speed.

Nigel

<hr width=100% size=1>Medway Motor Yacht Club
<A target="_blank" HREF=http://www.mmyc.co.uk>http://www.mmyc.co.uk</A>

 

[hlb]

Re: Horses for courses

I dont think mine take off much really. But one sticking out in knowmans land, cant do alot of good. Gad I'm strugling with the new vary focal glasses and the cunfuser thingy...!!

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Haydn