Thoughts on Rope Cutters, please

[Mikehp0]

I took my Prestige 32 to Bournemouth Pier yesterday to watch the Air Show. We had a great day. There seemed to be far fewer boats there than previous years. However, late in the afternoon, I had to do an emergency anchor lift and engine start to avoid a member of the "Birmingham Navy" who was drifting in a knackered, 20ft speedboat. "You're ***** drifting, not me" he said. He had a bit of string dangling over the bow with a tiny anchor probably just about touching the bottom. I had a heavy plough anchor, chained with over 4 times the depth in scope and a GPS alarm set. As I tried to explain this to him and his shirtless, life-jacket-less but heavily gold encrusted crew, I ran over a trailing stern line (one of mine, I'm embarrassed to admit) and stalled my starboard engine.

I dived in to try to free it but without goggles or mask I found it impossible. I called the amazing Seastart and their Pete was alongside in minutes - he'd had a busy day. He dived in and freed the rope (which strikes me as well beyond the call of duty) but after he left to tow someone else to Cobb's Quay, we discovered that the starboard engine had shredded a compressor belt. Pete's view is that the force of the sudden stall did it.

I had a spare belt on board but couldn't manage to work out how to fit it so we decided to head for Berthon. Without a compressor, the engine won't do more than 1800 revs. However, with my former RAF Tornado pilot father-in-law at the helm, we somehow went "over the hump" and the turbo kicked in and we ran up to full speed. He claims he put her into a dive! She ran beautifully all the way home - albeit with the proviso that we couldn't slow down. It was a bit like the film "Speed"!

Two questions for you.

1.Given that she ran so well at all revs on the way home, should I spend the money on another lift? She had one 2 weeks ago.
2. What do you think about rope cutters/strippers? I've found Ambassador Marine's website and their range of shaft-drive compatible rope strippers - see http://www.ropestripper.com/strippers.php

I look forward to hearing your views.

 

[Bandit]

I assume you have shaft drive?

I have QuicKutter fitted to my boat, see http://www.h4marine.com/QuicKutter01.htm

From a drag point of view its about the same cross sectional area as my thumb.

The advantages are: simple design , durable and minimal drag. As used by RNLI and some of the grey funnel line.

The rotating blade types have much greater water disturbance and drag and on some occasions cause cavitation on the propeller.

The old rule of thumb with rotating blade type rope cutters was they cost you a knot so substantial increase in fuel burn per Mile through the water

 

[boatmike]

I would second that. I really don't like the nasty serrated chopper things and have QuickKutters fitted. The advantages are
1. No reduction is speed
2. No terminal nasty smash ups if you are unfortunate enough to catch a chain or steel cable
3. Nothing works better so no reduction in rope cutting performance compared with anything else
4. No wearing parts or bearings to worry about.

Need I go on?

Only disadvantage is that they are unjustifiably expensive in my view for what they are even if like me you have your own lathe etc and can do it all yourself. If you need someone else to fit it for you its a simply ridiculous price on any small craft and I can see how people come to the conclusion it can't be justified and fit the very simple disc type which work to an extent and are better than nothing.

 

[Bandit]

Do I need a Ropecutter?

I have had shaft drive boats for 25 years and for 20 of those my boat has had rope cutters.

I have accidentally picked up pot lines on half a dozen occasions and you hear the cutter work and you see the debris.

I have stalled both engines when I went over a cheap woven tarpaulin and broken free with one engine and limped to my nearest port, it was about a cubic metre of the stuff that was removed by a diver but also a bent prop and shaft.

I work in a boatyard and we see a regular number of boats that get towed in with no propulsion and a variety of reasons, Fishing net ( absolutely no excuse this is thrown overboard) ships mooring lines ( same again) , crab pot lines , tyres ( rope cutters would not work on those) etc. Boats picking up their own mooring lines is also a popular one

There is not always damage caused , but resulting damage is often : bent props, bent shafts, damaged cutless bearings . The worst is when a twin screw boat catches a rope around both shafts and it winds the prop shafts and p brackets in towards each other with a lot of damage.

In extreme cases debris can cause a stern seal to leak or disable a boat near a lee shore but these are rare.

I saw a 52ft Sunseeker with a pair of 700 hp engines ( apparently the builder does not like rope cutters due to cavitation and speed drop of the rotating blade type cutters) a pot line had melted around one shaft and destroyed the cutless bearing and if it had run much more would have damaged the shaft.

We have loads of crab pots some better marked than others and our fair share of discarded, net , rope and other debris in our waters.

Personally I would always have rope cutters.

 

[JSYmartini]

I heard of a boat that turned up in Guernsey years ago after getting a heavy mooring line with steel in it round the prop. The owner did nothing, just came back in on the other one.

Engineer called in, goes into the engine room and finds the motor span upside down....

 

[Mikehp0]

In the end, I bought a telescopic pole for my GoPro ( a "selfie stick", my teenagers call it). I got great still and video images of a very clear prop, Skeg and rudder. No need for a lift and I can now take selfies wherever I go (assuming I'm happy to carry a white stick). Thanks for all your help. Will fit the cheap easily installed rope cutters at next lift - the last knot or mpg doesn't really matter - I'm a 50 hour per year boater.

 

[hector]

Not sure I would bother, have been boating 20years + crossed channel many times, 2000hours or more, and caught a rope just the once, and managed to remove myself. As previously said, join sea start, top guys.