Poor rope or poor weather?

peterandjeanette

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Having just returned from a week trip to Guernsey and Cherbourg I have had time to examine the remains of my mooring ropes.

It may seem a long time ago now, but the Bank Holiday storms extended to the Channel Islands. We were secured in Beaucette Marina, round the corner on the visitors berths. As the wind increased on Sunday night - reported at F9 N/W - the seas started to grow and enter the marina at an alarming rate.

Out came the new rope - 14mm - and the new rubber snubbers - and all the fenders I had on board. Two stern lines, one bow line and three springs.

The waves hit the breakwater, bounced across the outer marina and threw us against the pontoon very hard. The waves continued to the quarry wall 3 metres behind us, rebounded, and threw us off the pontoon. This continued all night so no sleep at all.

All ten fenders did a good job of protecting us from the inbound waves but at first light I heard - and felt - the bow rope part. With SWMBO hanging out of the forehatch and me hanging on to everything on the pontoon we managed to secure another two ropes to the bow.

(All this time a yacht moored ahead of us was also in difficulty. His crew was searching the car park for old tyres to act as fenders!!)

By full daylight all began to calm down.

The marina management was aware of what was going to happen. They had roped all their inner marina pontoons together to prevent too much movement. Unfortunately they could find no room inside the marina for us - although the afore mentioned yacht managed to secure a berth inside for the following high tide!!!.

The rope that parted was the new 14mm rope on the left. The stern rope, also new, on the right looks as though it was about to go. My only thought was, if I had used heavier rope, would it have pulled the deck fittings out? Maybe that 14mm rope is not enough to hold a 12 tonne boat.

IMG_0009500x375.jpg


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OK - hit me. Where did I go wrong?

1. Rope too small
2. Boat too big
3. Don't put into Beaucette in ANY sort of a blow
 

Divemaster1

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Two things from me;

IMHO ...14 mm rope is not enough for a 40 ft MY ... 16 - 18 mm should be the norm... We have a 45ft MY and use 20mm ..... and have damaged those in bad weather!

Rope type .... the type in the picture have no flex or give (know you state that you used new "rubber snubbers"), so by default would snag as they do not give.
Three strand braided hose or octoplait would be my pref. for mooring. I know the type in the picture is soft on the hands and makes for more pleasant handling. I have a couple onboard, but they are replaced if we are mooring up for more than a couple of hours, as they dont give and tends to snag more than thre strand.
 

duncan

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echo Alf

elasticity - elasticity - elasticity

the boat is going to move and build up inertia which will need to be damped not simply stopped - the latter is possible with about 20mm but the shock loading on boat and pontoon cleats ............. /forums/images/graemlins/crazy.gif

back in the Dec (?) storm the bow rope on Phaeton failed - 16mm on a 2.6 ton boat - as it simply didn't have the stretch and was taking one hell of a pounding (I got another line on when the first strand parted).
 

AIDY

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we were in cherb on the same night. one of our ropes decided to give up on us too. lucky for us we were being blown of the silly diving board pontoons. but the mobo next door got a hole in the hull from rubbing up against the pontoon. and a mobo on q pontoon started to take on water... fire chaps came to start pumping.
 
D

Deleted User YDKXO

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Agree with Divemaster1. 14mm is too small for a 40 footer in a blow and whilst that type of braided rope has a high load capacity, it has little flexibility. IMHO, the traditional 3 strand type nylon or polyester rope is better for mooring because of it's flexibility even though it's less pleasant to handle.
The other v important issue is the length of the lines that you used. The longer the line, the greater the flex and the better the angle is for resisting chafe in fairleads and, if you have to use short breast ropes fore and aft, some of the load on them can be relieved by using long spring ropes
 

Bandit

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I have a 36ft boat 10.5 tons and the main mooring lines are
18mm 3 strand nylon or polypropylene and I have some 18mm 8 strand anchorbraid. last winter I had one rope go in a gale down to one strand over a period of months but in the winter I have second head and stern lines that are slightly looser than the main lines, ie one goes then the load goes on the second.

I think part of the problem is thetype or raope you used with the exterior woven casing and a loose strand core. This type of rope is very prone to wear , the casing goes and there is no resistance to wear with the loose inner fibres.

3 strand ropes have a much tighter weave than the premade docklines you appeared to be using.

You would find 3 strand nylon or polypropylene much more durable and 18mm much stronger.

See the English Braids website for breaking strength etc.
 

adrianb

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Hi Peter

We too were in Guernsey and Cherbourg - Victoria Marina on the Sunday night and can confirm - my 14mm 3 strand nearly parted, and I had triple lines out, and all available fenders - including octoplait of the same size, and Fairline braid on braid warp, which was 18mm.

I can testify wholeheartedly to having no sleep, my spare ball fender was making a hell of a noise on the hull(it was on the oposite side to the pontoon, in case of rafting craft). It was too dangerous to retrieve it, now if I could have got hold of it through the port I would have stabbed it !

I will be purchasing some thicker octoplait soon !

Pity we missed you.

Adrian
 

peterandjeanette

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Hi Adrian

Spotted Nauti Secrets (what a beauty) in St Peter Port but didn't have chance to say hello. Was surprised that the marina seemed quite empty.

I thought you had done the wise move by not opting for Beaucette. Didn't think you would also have a bad night.

Hope to catch up with you again soon

Peter
 

jimg

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No, Beaucette is NOT the place to be in a blow.
I have been there in those sorts of conditions and several boats were seriously damaged on that occasion.
The marina is an old quarry and the waves just bounce around the walls, a very scary place in a storm!
 

RogerRat

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Hi Peter,
Seems you really know how to pick the weather. Beaucette has a rep for nightmares in a north easterlys' but what a great place. /forums/images/graemlins/cool.gif

I was surprised to see that you were using 14mm lines as well, I def. agree with the Divemaster and Deleted User. You have to go heavier, but I think Mike meant stretch/elasticity not flexibility as most ropes are flexible.

Nylon being the classic and the longer the springs the better, if its blowey. If you look at the boats moored with very short breast ropes they just thump away, jerking at their when there's a swell, then snap in a matter of hours. It can't do any of the deck fittings any good either.

You could use 16-18mm soft plat for general use and double up with 18mm 3ply when strong winds or minimal shelter is forecast.
 
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