Ropes for trot mooring

[Reptile Smile]

Hi all,

I am, as ever, on a nano-budget, but my mooring will be a trot mooring in St Pierre Pill in the Bristol Channel. Whilst the mooring is sheltered, it does have to contend with a pretty major tidal surge.

I need to connect two mooring ropes to the chain (5 metres apart), and then a single riser rope coming up from these to the buoy, both fore and aft. What sort of rope and what sort of diameter should I be getting for these?

 

[Reptile Smile]

Hmm, didn't say - the boat is a Copland Foxcub 18' trailer sailer

 

[KAL]

Hi all,

I am, as ever, on a nano-budget, but my mooring will be a trot mooring in St Pierre Pill in the Bristol Channel. Whilst the mooring is sheltered, it does have to contend with a pretty major tidal surge.

I need to connect two mooring ropes to the chain (5 metres apart), and then a single riser rope coming up from these to the buoy, both fore and aft. What sort of rope and what sort of diameter should I be getting for these?

I would have thought that the mooring authority would provide the buoys for you to tie your boat to. If they don't then I'd suggest you shackle chain (8mm at least) to the main mooring chain and into a rodded buoy with a ring on the top. Then tie some nylon or polyprop line (8mm or so) between the mooring buoys to act as a pick up line. Putting a small pick-up buoy onto this line prevents it from sinking in the water and makes the job of picking up your mooring much easier.

Next, make two mooring ropes for each of bow and stern (i.e. four in total) and shackle these independently to the ring on each mooring buoy. I'd suggest tying the 'boat' end of these lines to the mooring ring while the boat is out playing. It keeps them dry and clean, otherwise you get crud all over your foredeck and stern every time you re-moor.

Make sure you 'mouse' your shackles, (through the small hole in the pin) either with monel wire or a plastic tie, as they can come undone really easily, otherwise.

You then approach your mooring, pick up your pick-up buoy to steady yourself in the stream, then tie on port and stbd lines fore and aft. The doubling up gives you 4x peace of mind and also keeps the boat straight in its slot if there's a crosswind.

Have fun, but do double-check that the mooring authority doesn't supply the fore and aft buoys. I've never heard of one that trusts us to supply and attach our own!!

 

[stownsend]

If your with CDYC, have a chat with the mooring master.

Cheers

Stu

 

[VicS]

I would have thought that the mooring authority would provide the buoys for you to tie your boat to. If they don't then I'd suggest you shackle chain (8mm at least) to the main mooring chain and into a rodded buoy with a ring on the top. Then tie some nylon or polyprop line (8mm or so) between the mooring buoys to act as a pick up line. Putting a small pick-up buoy onto this line prevents it from sinking in the water and makes the job of picking up your mooring much easier.

Next, make two mooring ropes for each of bow and stern (i.e. four in total) and shackle these independently to the ring on each mooring buoy. I'd suggest tying the 'boat' end of these lines to the mooring ring while the boat is out playing. It keeps them dry and clean, otherwise you get crud all over your foredeck and stern every time you re-moor.

Make sure you 'mouse' your shackles, (through the small hole in the pin) either with monel wire or a plastic tie, as they can come undone really easily, otherwise.

You then approach your mooring, pick up your pick-up buoy to steady yourself in the stream, then tie on port and stbd lines fore and aft. The doubling up gives you 4x peace of mind and also keeps the boat straight in its slot if there's a crosswind.

Have fun, but do double-check that the mooring authority doesn't supply the fore and aft buoys. I've never heard of one that trusts us to supply and attach our own!!

The ring on the top rodded type of mooring buoys is sometimes/ often/ usually not suitable for mooring. More likely that the mooring ropes should be attached to the chain below the buoy.

 

[oldbilbo]

'Zackly as VicS says....

Look carefully at the two pics below. The first one shows a normal arrangement of the underside of a 'rodded' mooring buoy, and it is common to find an owner who has shackled his riser chain to the prominent elongated link shown.... and his boat ropes to the ring on top.

At the risk of waking the 'armchair admirals', that's a long way less than adequate.

On the second pic, look closely. The elongated link is reatined in place by a quite small and very-swift-to-corrode split pin. With your boat secured via the ring on top, the whole kit-and-caboodle is dependant on that split pin. Once it goes, the buoy will rotate on the elongated link within a day - or an hour - or two. Then your boat goes walkabout.

Yeah, it's a locknut. Yeah, locknuts corrode in salt water....

That's why it is VIP that your boat ropes are secured solidly to the top of the riser chain, with the buoy simply holding the weight up.

 

[lw395]

If you want to make a rod buoy like that reliable, my method is to use two full nuts. Assemble with loctite. hold the first nut in the vice and tighten the second onto it using a BIG spanner.
Then drill through the second nut 4mm hole, tap it M5, countersink and put a zinc plated csk M5 machine screw through it, again loctite. Then bolt an old anode to the eye.

Worked well for me. Think the rod was 20mm?

The split pin in the picture is only any good for damaging the ropes of cretin sea-schools who lassoo your mooring when you are away.

 

[lw395]

That's why it is VIP that your boat ropes are secured solidly to the top of the riser chain, with the buoy simply holding the weight up.

So the eye on top the buoy can wreck your topsides...

 

[KAL]

'Zackly as VicS says....

Look carefully at the two pics below. The first one shows a normal arrangement of the underside of a 'rodded' mooring buoy, and it is common to find an owner who has shackled his riser chain to the prominent elongated link shown.... and his boat ropes to the ring on top.

At the risk of waking the 'armchair admirals', that's a long way less than adequate.

On the second pic, look closely. The elongated link is reatined in place by a quite small and very-swift-to-corrode split pin. With your boat secured via the ring on top, the whole kit-and-caboodle is dependant on that split pin. Once it goes, the buoy will rotate on the elongated link within a day - or an hour - or two. Then your boat goes walkabout.

Yeah, it's a locknut. Yeah, locknuts corrode in salt water....

That's why it is VIP that your boat ropes are secured solidly to the top of the riser chain, with the buoy simply holding the weight up.

I'd agree entirely. However, our boat is moored in the Dart, and the Harbour Authority stipulate that the boat's mooring lines are attached to the ring on the top of the buoy. I just duz loik oiz telled...

 

[DogWatch]

If you want to make a rod buoy like that reliable, my method is to use two full nuts. Assemble with loctite. hold the first nut in the vice and tighten the second onto it using a BIG spanner.
Then drill through the second nut 4mm hole, tap it M5, countersink and put a zinc plated csk M5 machine screw through it, again loctite. Then bolt an old anode to the eye.

Worked well for me. Think the rod was 20mm?

The split pin in the picture is only any good for damaging the ropes of cretin sea-schools who lassoo your mooring when you are away.

Why not just weld it up if you are going to go that far?

 

[BlueLancer]

Why not just weld it up if you are going to go that far?

I would have thought that welding would cook the galvanising off, encouraging rust.

 

[lw395]

Why not just weld it up if you are going to go that far?

I am competent in the use of spanners, vices and so forth, but I don't have welding kit or the ability to use it properly.
I've always wanted to learn to weld decently, but a mooring is not where I'd do my early practising!
It's also a possibility that welding the nuts will damage the plastic buoy.
Not to mention ruining the galvanising.
Although my method sounds like a rigmarole, it really doesn't take long. It also has the advantage that it can be undone. In fact I've undone a buoy rod that's had this treatment after two years' use, when the inflatable part of the buoy was destroyed by some swine lassoing it.

By the way, I also replace shackle pins with bolts and an extra locknut the same way. I don't have much confidence in simply mousing mooring shackles. Our local mooring contractor welds shackles that will be underwater. He seems to be insistant on welding them properly, he does not trust a little dab of weld that some people use.

 

[oldbilbo]

Every mooring contractor I've listened to - more than a score, now - is absolutely, swear-on-a-stack-of-bibles, on-my-mother's-grave, certain that HIS methods are THE RIGHT ONES. Boats still break free of their moorings, however, and it's always 'someone else's fault'. They all have a 'rogue's gallery' of failed and very-nearly-failed kit....

Few owners I know give more than a cursory glance at their mooring tackle, and that's one reason for ever-escalating insurance premiums.

The thread, male and female, on shackles and buoys' through-rods seems to erode faster than other parts. Physical abrasion of rust scale by movement under load also seems to play a part. There seems no substitute for regular, critical inspection and 'as big as possible' gear.

Right now, it's blowing hard along the coasts of Southern England and South Wales. When did you last check YOUR mooring gear?

 

[lw395]

Good pictures. It's quite amazing how thin a bit of chain can get without actually breaking!
We now use mooring contractors for virtually everything up to and including the buoy. At low water, it's not too hard to capsize the buoy and inspect the swivel and connection to the riser. I've done it by attaching a 4:1 tackle (old mainsheet system) to the riser and raising the riser by hand.
Haven't spotted anything worth chasing drifting out of the harbour yet. I think this morning might have been a good time to watch, some big winds on Chimet. When all is said and done, the incidence of boats breaking free from swinging moorings is pretty low, but you wouldn't want yours to be the one. I don't own my own yacht at the moment, but when I did I was far happier with it on the mooring than under the care of our esteemed boatyards...

 

[rob2]

Going back to the original question, the ropes should be as large as you can attach to the boat and protected against chafe - many people here recommend using time-expired firemans hose for this. I had a fore and aft mooring for a while and had two heavy lines to each buoy, I think they were 20mm polypropylene. Normally I would not advocate polyprop, but in large sizes they seem to survive OK despite UV degradation. Anything too large to drop onto your cleats or pass through the fairleads will be wasted, unless you can lead them to other strong points such as a winch or samson post. Three strand with large eye splices are my preferrence, I don't have to go around re-securing the ones my crew have done.

I also prefer to attach directly to the riser chain and weld the shackles if you can. I'm convinced that modern shackles are made so that after galvanising the thread is an easy fit, so there's hardly any steel in the thread pattern! Our club moorings got much better wear by using large lifting grade shackles (ungalvanised) and mousing or welding the pins.

If the buoys are a suitable distance apart, you won't ride over them under any conditions, so you won't have to worry about the top eye scraping the topsides.

I spliced a light line between the two strops each end long enough to stretch around fittings and get to the cleats, whichever way around I managed to grab the mooring. Another light line runs between the strops with a short riser to a pick-up buoy half way. It's probably best to shackle the pick-up line on so it can be dettached and walked around to the other side when wind and tide dictate depoarting the other way.

Rob.

 

[DogWatch]

Right now, it's blowing hard along the coasts of Southern England and South Wales. When did you last check YOUR mooring gear?

Last weekend, but only because I finally removed my third fore and aft 24mm winter strops attached down the chain rather than at the top of the trot buoys. We also dry in a couple of feet of river water so I often have a quick shufty at the chains.

But your point is valid and some of those images frightening. I have seen chain go bad, but never that bad, even on an open swinging mooring, of which I laid many in my home village. I have dug up some antique moorings in my time too, never like that... Something else must be going on with a few of those you posted.

 

[lw395]

Last weekend, but only because I finally removed my third fore and aft 24mm winter strops attached down the chain rather than at the top of the trot buoys. We also dry in a couple of feet of river water so I often have a quick shufty at the chains.

But your point is valid and some of those images frightening. I have seen chain go bad, but never that bad, even on an open swinging mooring, of which I laid many in my home village. I have dug up some antique moorings in my time too, never like that... Something else must be going on with a few of those you posted.

I've seen bits of chain like that. Usually the bit that swirls around the seabed on a hard bottom. It's like grinding paste! The bits that are buried in mud or never touch the bottom usually look much better. It's been said that empty moorings wear faster than one with a boat on in this way, I can see some logic in that!