Another mooring question!

[Kelpie]

It seems there are as many ways to lay a mooring as ways of skinning a cat, and I've had slightly different advice from everybody I've asked.
However I'm now coming towards a plan and would like some feedback before I go hauling lumps of metal off the back of boats.

The mooring is to hold a Wayfarer (16ft, very light) so a lot of the advice has been overkill. The water will vary from about 6ft to 22ft depth, and the ground is soft mud. Th location isn't very sheltered but I take the baot home in the worst weather anyway.

My plan is to lay two sinkers, which are 75kg cast iron manhole covers. I will make two holes in each one, and feed the ground chain through one hole and then put on as big a shackle as I can get to stop it pulling through the hole. The other hole will take a length of rope which is tied on to the ground chain; the idea is to form a 'Y' with two attach points to the manhole cover. Is rope a terrible idea? Maybe I'd be better with a short length of chain and more shackles?
That would mean buying more stuff that I don't have!


Anyway the ground chain is 4m in length, and 13mm galv. In the middle I'll shackle on the riser, which is an 8m length of 10mm chain. At the top of this chain I'll fit a swivel, and then a short length of 25mm nylon leading to the buoy.

 

[oldsaltoz]

G'day Rob,

Have you considered putting the chain through a singe hole at the centre of each man hole, this should provide better holding.

If you daisy chain them the nearest would act as a damper, reducing the load on the second man hole.
We used this method with railway wagon wheels from the scrap yard.

Avoid rope if you can, it rots, it chafes, and can cut easily.

Hope this helps.

Avagoodweekend......

 

[tomframe]

we used to cut a 44 gallon drum in half, lay chain in it and fill with concrete - job done for years.

 

[sailorman]

concrete sinkers work best with the underside cast "concave" to assist "suction"in muddy river beds

 

[steve_l]

My opinion, for what it's worth. But I have laid my own moring and helped lay others...

As you say, it's only a Wayfarer and will be removed during any hard blows, so, using what you have available...

Drill a hole in the centre of each cover so that the 13mm chain can pass through and attach a shackle to each end large enough so that it can't pull back.

Shackle the 10mm riser to the centre of the 13mm chain.

Attach a swivel to the top of the riser and the bouy to the top of the swivel.

You can attach a pick-up line and bouy to the top of the swivel, under the riser bouy, so that the whole top assembly can turn without twisting the riser.

When laying, lower the man-hole covers into place with the chain coming from the top side. Keep the ground chain a little slack between the covers.

Don't just drop the man'hole covers over the side! They will probably turn over and/or plane away. Anyway, they certainly won't be where you want them.

Last important point... mark the bouy with some kind of warning "Dinghies only" or something. You don't want something bigger mooring up during a blow which could lead to
a) your mooring being moved to somewhere else - very inconvenient
b) a claim against you as the owner of the mooring - very costly

Good luck! Let us know how you get on.

-steve-

 

[Lakesailor]

Yes. I can't see the point of two chains per cover. Use shackles with pins that poke out past the threaded part and peen the thread on the pin so that they cannot come undone.
More shackles, more risk. I can't see the point of the rope at the top of the riser either. A real weak point. Put the swivel under the buoy and nylon strop with a thimble at one end and a soft loop at the other shackled to the buoy as well. Put a pick-up buoy on the end of the warp (perhaps with a light line to the soft eye) and just pick up the strop to moor, leaving the main mooring buoy in the water. Use a back-up warp as well. (belt and braces).

These concrete blocks are used on Windermere as the standard mooring. Boat more than 25ft usually have two blocks.

This pic below shows the new riser to the swivel under the buoy (hauled on deck for maintenance, I never hauled the buoy out otherwise) There is a year-old strop attached to the swivel and a new nylon strop attached to a tail on the riser chain. Both strops had a soft loop at the other end which were connected to a bridle of small diameter line tied to the pick-up buoy so that both strops came up with the pick-up.

This mooring system kept two 18ft boats safe for 5 years on Windermere which can get a bit choppy in the winter.

 

[Twister_Ken]

Two other minor points: make sure the cleat(s) and fairlead(s) on the Wayfarer are up to permanent mooring - good backing pads maybe – and that the final mooring strop is not to big to wind around the rather diddy cleats you'll have on a dinghy.

 

[Kelpie]

Thanks for all the replies! Especially thanks to Lakesailor for the pictures.
One hole in each manhole cover sounds much better. Gonna be fun trying to make that hole... welding torch maybe?

Oldsaltox suggested a single line with both weights, and this had crossed my mind. I'd imagine it would let the sinker oin the end of the line really bed in properly, with the first one moving around a bit. Putting them on a ground chain with the rise in the middle does seem to be commoner though- maybe because it gives you a smaller swing area?

As to the boat itself, I'm not even bothering with a mooring cleat. The warp passes through a bow fairlead, is wrapped around the mast, and then down to centreboard case which is a structural part of the hull.

 

[Lakesailor]

Centreboard case!! Eeek. I assume it's a grp Wayfarer.

I would put a foredeck cleat on with a big backing pad. Just my personal preference, but putting lines around the mast is asking for unintended damage. Summer squalls can be vicious.

 

[lw395]

You might find that leading the mooring warp a long way back in the boat accelerates chafe, because the stretch in the warp means the rope is always moving over the fairlead etc with every ripple. I'm also never a fan of using the mast as a mooring or towing point. Just something to watch from personal experience. A stout towing eye on the bow perhaps? This would also pull from lower down maybe more stable?
Whatever you do, be prepared to watch it and change anything which shows the slightest signs of chafing or excess wear, it seems to be quite unpredictable sometimes. If the boat jerks and snatches on the mooring, something isn't right and wear will result. Sometimes a heavier or lighter riser will give a more comfortable mooring in the prevailing conditions.
Your ground tackle sounds fine to me, good luck with it.

 

[Kelpie]

Oh right, thanks for that, I hadn't considered there to be any problem with using the mast and cb case. It is indeed a GRP hull, but the topsides are marine ply.

Took a spin out above my intended spot today, in my inflatable, at low tide. Looks good to go- now I just need to figure out how to make hte holes in the manhole covers. Anglegrinder, maybe?

 

[Lakesailor]

My inclination is to drill the holes. Cutting with an angle grinder will leave slots and cuts in the casting which may cause a break line if a sudden force is exerted on the riser chain. A drilled hole will have no point for forces to concentrate on.
Maybe a job for an engineering shop.

Someone like Cliff will be able to advise with more authority.

 

[KREW2]

What ever you use put a support buoy on the riser chain. This will reduce the snatch, 22 ft of chain weighs a bit. Use rope only as a bridle with a snubber to reduce snatch even more, but have chain as your main means of holding.

 

[Kelpie]

Not sure what you mena by that? DO you mean have a big buoy to hold up the chain, and then a second pickup bouy separate to that?

 

[Lakesailor]

I think he means the same as I said earlier.

 

[Kelpie]

How important is it to have the hole in the middle of the sinker? Local boatyard will drill one for me for £29+vat, ouch! I could make one myself using an angle grinder to cut off the back of a dished recess, but that would be towards the edge of the manhole cover.

 

[Lakesailor]

You don't want to pay £30 to keep your boat safe?

At the edge the pull would more easily break the suction on the sea bed.

 

[Kelpie]

£30 per hole, so £60. Plus vat. Yeah not the biggest expense in the world but remember I'm a dinghy sailor! I just bought a brand new jib for £80 the other day. So it seems like quite a lot for drilling two holes. And it made me think about maybe spending that money on an anchor instead- one of those cheap Bruce copies would surely get a good hold in the soft mud that I'm laying in.

The manhole covers have two handles on them- thin bars which I wouldn't trust to hold any force. But behind the handles are dished backing plates which are thinner than the rest of the metal. I'm thinking of cutting these off and then looping the ground chain through, shackling it back to itself. My only concern about doing this is that the chain could perhaps suffer more wear as it pulled through the holes.

 

[Lakesailor]

OK. Cut both delves off and put a length of chain through both and up to the top, then put the shackle through those two ends and on to the riser or a bridle between the two lids.
Still don't think it's as good as a vertical pull on the centre of the sinker.

 

[oldsaltoz]

[ QUOTE ]
How important is it to have the hole in the middle of the sinker? Local boatyard will drill one for me for £29+vat, ouch! I could make one myself using an angle grinder to cut off the back of a dished recess, but that would be towards the edge of the manhole cover.

[/ QUOTE ]

An oxy cutter would be cheap and fast.