Rope cutters...

SeaAndSea

SeaAndSea

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....how many people have them fitted? We go back in the water in a couple of weeks so wondering if we should fit. Can't find a lot in the way of reviews online - what's the opinion of the group please, worthwhile? Which type is best? To be fitted to a pair of Caterpillars 3208s on a Trader47. Cheers
 
Not knowing what your cruising speed is, if drag and fuel burn is an issue fit H4 quicKutter shaft rope / line cutter .

I have them on my Aquastar 48 and they work well absolutely minimal drag, the blade bolts on to your "P" Bracket an runs over a composite bobbin bolted to the front of the propeller boss and from a drag point of view has a minimal cross sectional area of about 20mm x 15mm approx.
 
I've had a fouled prop twice. Once by a large brown polypropylene coal sack, the other time by a discarded metre-wide bundle of orange polypropylene fishing net. That one needed a diver to cut it off, the sack floated off after several astern/ahead shifts. I retrieved it and took it ashore. No line cutter would have been the slightest use in either case.

I've often wondered if I'd ever read a post by someone who has one and had a single thinnish line conveniently offer itself up to be cut. Or would they know if it had?
 
I have QuicKutters fitted on basis of the RNLI use them. Don't know if they have been used in anger or not; not aware of it.
 
Mines a sail boat, but I’ve definitely caught something round the prop twice and my cutter did it’s job. The first was a definite clonk-chop-chop and no interruption. The second was on arrival in Cherbourg. Started engine, dropped sails, engaged gear to motor into marina, nothing! Several forward and reverse selections nothing. No revs, no drive, and being blown towards the rocks. Quickly re hoisted sail and sailed back out to the Grand rade to give myself some space. Continued with the same forward and reverse selection and you could feel a small increase in the rotation of the prop shaft. Still no rev. After a few minutes it cleared and engine revved and I could motor in. Dived the next day to find all clear. Long reply I know, but I for one believe that a rope cutter is a very beneficial addition.
 
Bandit said:
Not knowing what your cruising speed is, if drag and fuel burn is an issue fit H4 quicKutter shaft rope / line cutter .

I have them on my Aquastar 48 and they work well absolutely minimal drag, the blade bolts on to your "P" Bracket an runs over a composite bobbin bolted to the front of the propeller boss and from a drag point of view has a minimal cross sectional area of about 20mm x 15mm approx.
Click to expand...

crusing speed - 10-12 knts
 
Rope cutters that have a blade that rotates in front of the propeller, ie the cutter blade stays in the same place relative to the prop often cause cavitation at higher speed on the prop blade.

Rope cutters with rotating and fixed blades such as Stripper and the fixed discs with sharp blades or discs with serrated blades all cause significant drag. By drag think loss of speed and more fuel per mile at speeds of low twenties think 1 to 2 knots loss of speed. Sunseeker don't like fitting rope cutters because of this and arguments over speed.

We had a 50ft Sunseeker in one day , no cutters and a disc of rope had melted underwater at speed to fill the gap between the prop boss and the "P" bracket, we had to remove the prop to get the disc off. The Cutless bearing had overheated and destroyed itself in fact it smelt of burnt plastic, all at speed under water and 25 + knots.

I have had Stripper cutters and you know when you go over a pot rope it sounds like someone hitting the hull repeatedly with a hammer.

We have a plague of crab pots around the Channel Islands some better marked than others, some are plastic cans or even underwater, as well as other floating crap, nets, woven bags think cheap garden waste bags to larger.
This is why I don't run in the dark, in rough weather you cant spot pots either.

With Quick Kutter you don't hear the banging noise because it effectively rips or shaves the rope to destroy it and you could quite easily know you have been over a rope.

I have had rope cutters on shaft motor boats for 35 years now, with Strippers I certainly went over several pot lines, with eh Quick Kutters I don't know.

I have only got stuck once when with a twin screw boat off shore on the way to france 20 miles from land I went over a large garden waste bag which stalled both engines ( 370 hp diesels each). A sloppy day so I restarted the engines and eventually ahead stall, restart reverse stall etc etc I worked one engine free and limped in to LesArdrieux at 4 knots, a large wheelie bin of destroyed bag was removed by the diver, one prop was depitched, one shaft bent.

Eventually you will find a net or mooring rope that your cutter cant cut, I have seen all makes of cutter damaged or broken off.

I would not run a motor boat without rope cutters.

The best I have seen was a boat that came in complaining of fouling and he had a car tyre perfectly fitted around all of the blades on one prop, that caused a drop in speed.
 
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