Trot Mooring suggestions ???

[seaboy]

Any suggestions how best to lay a new Trot mooring for a 6.5mtr powerboat with a max rise and fall of 4.5mtrs and dries out on all tides with mud/sand bed.

ie:- length of chain from bed anchor to buoys and distance between anchors, etc.

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[Guest]

Harbour Master and local Yards / Clubs will advise - as it will most likely affect your Insurance if you ever make a claim and you do not meet local / HM specs.

<hr width=100% size=1>Nigel ...
<A target="_blank" HREF=http://www.qqbaltic.com/index.html>http://www.qqbaltic.com/index.html</A> For all those disbelievers ! /forums/images/icons/cool.gif

 

[seaboy]

Contacted Harbour Master
Could only suggest the distance between the bed anchors be of at least 3mtrs greater than the length of the boat, where the max. rise is 4.5 mtrs and the boat 6.5 mtrs.

Anyone know of a Website with such info, regarding the laying of a mooring or any further suggestions.

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[jhr]

There's a guy on the MoboChat forum called Dave Knowles, who was talking about having laid a drying mooring on the Beaulieu River last year for his Cleopatra (about 7 m, I think) . Might be worth a pm to him?

<hr width=100% size=1>Je suis Marxiste - tendance Groucho

 

[Trevor_swfyc]

Yes most Harbour Masters say moorings must be laid in accordance with the HM directions or to the satisfaction of the HM. I have not seen any directions or regulations regarding this for our area.
If it helps I am happy to give rough details of what I consider best practice.

The sinkers should be 10 metres apart, we use concrete set in a tyre approx 205x60x15, use approx 1 metre of inch chain set in the concrete with a length of scaffold pipe as a crossbrace, leave for two weeks to set before use.
You will require 10 metres of ground chain we use 3/4 inch and 5 metres of riser we use 1/2 inch. You will also require a swivel do not skimp on this item as it is a potential weak link in the system I prefer stainless, five shackles and a mooring buoy which must be able to be support the chain and be seen clearly so big is good.
Lay the mooring out at low tide such that the ground chain will lift two metres this will give a total of 2.5 metres of chain over spring tide height. Bury the tyres in about two feet maintaining the two metre lift available on the ground chain.
The swivel can go either end of the riser chain if it is stainless but would put it between the buoy and riser if not as the sand with soon grind it away.
I would not use anchors, reason being I saw a boat go down after sitting on an exposed fluke of an anchor after it became exposed by tide scouring. We float out the sinkers using 2 x 5 gallon empty plastic drums as part support with the other end of a support line to the club boat once over the mooring drop the line from the boat and pull the drums on board.
Hope this helps you in some way.
All the best.
Trevor

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[Guest]

I would only use galvanised throughout ....... and not mix stainless with galv.

Otherwise sounds ok ...... ??

<hr width=100% size=1>Nigel ...
<A target="_blank" HREF=http://www.qqbaltic.com/index.html>http://www.qqbaltic.com/index.html</A> For all those disbelievers ! /forums/images/icons/cool.gif

 

[seaesta]

Nigel I dont agree re galv chain. The riser chain genrally wears out before it rusts out and gound chain should be massive enough not to corrode for a very long time (or may sink in mud in which case it will not normally rust out for many years).
Best advice I can give is to find local lift gear testing service and see if they have any scrap chain they will sell cheap. If you have to buy new then Agricultural Suppliers are much cheaper than Chandlers.
Boat jumbles often have bods selling old chain.
Good luck
Martin

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[Guest]

Sorry - but no !

Sorry - but I have to diasgree ....

I buy from Marine scrap yards who have loads of ex ships derrick chains and odds / sods. For ground chain - I would approach the loacl Gravel Barge / Dredger yards as they replace the chains on their dredgers etc.

Why use galvanised ? You can see the deterioration of mild steel or galvianised chain clearly and it can be 'rung' to hear its condition. Stainless chain and swivels give no warning whatsoever of failure as the metal will not derode or change before parting.

Sorry but years of sea-service, many moorings laid with clubs / fellow boaters etc. etc. and also copies of Harbour Master guidelines for Langstone etc. tell me I may not be wrong .... but you makes your choice .....

I can tell you that there have been a few boats on the wall in Langstone for using 'alternatives' but those that I laid and others who followed me - well I haven't heard of them breaking adrift yet !

The mooring I left with Tudor had 13ft 1" ground from a 4ft diamter concrete sinker, to 1.25" swivel, to 3/4" riser chain, then buoy - 2 in fact as I needed a strop pick-up buoy !, ending in 3/8 riding chain with 3 rope strops to differenet mooring points. (1 strop went to mooring bit, second to anchor windlass, third to base of mast) All chain, shackeles and swivels in galvanised ..... strops were 12mm nylon each.

I had no worries to leave my boat 12month on mooring with all the weather and exposure and never experienced any problems. Each year I would check it out and only ever had to eplace 1 ground to sinker shackle in all the years there.

Oh - finally ' never ever use a BOW shackle anywhere on the mooring trot ...... why - I had a good example of a bow shackle that 'turned' and bore load across the bow instead of via the pin and bight of the shackle ....... it snapped and that was a comercial ships bow shackle of 1.5" ...... ok the waether was a force 11 going through Havant Quay at time.

Sorry - but I am not convinced ......


<hr width=100% size=1>Nigel ...
<A target="_blank" HREF=http://www.qqbaltic.com/index.html>http://www.qqbaltic.com/index.html</A> For all those disbelievers ! /forums/images/icons/cool.gif

 

[seaboy]

If I am using a 'trot' rather than a 'swing' mooring as mostly described above, would 1/2" be ok for the risers, with a 20ft boat sheltered in a creek with minimal tide run only from the creek.

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