Mooring Bridle Lines, Length and Method

[ireaney]

As I will be using a swinging mooring instead of a marina for my catamaran of 40ft in length, what I am asking is, what length should the bridles be on each side.
I will be securing each end of the bridles to the top of the riser chain underneath the main mooring buoy and the other ends (when the boat is not moored) to the pick up buoy, so the idea is to get the pick up buoy on board – temporarily attach it to a cleat on the front cross beam - and then un clip the bridles and attach each to either end of the front cross beam, then release the tension on the pick up buoy.
Also when leaving the pick up buoy with the bridle attached (when away sailing) so as to keep the bridle ropes weighted down so as not to get fouled in passing boats propellers would it be feasible to have a short length of chain in the middle of each bridle line or could this cause damage to the boat when moored?
I look forward to any sensible suggestions and answers.
Thanks
Ian

[GordMay]

Assuming a beam of about 20 feet (between cleats), you'd want a minimum of 15 feet per bridle leg, plus cleating length and spare adjustment length. I'd suggest a minimum bridle length of 30 feet, per leg.

[Woods Designs]

I would use short bridles to reduce the swinging room. If your CL spacing is, say 15ft, then I'd use 10ft bridles.

I assume you will use nylon bridles. Probably by the time you add shackles and swivels they will stay sunk when not in use. I don't know anyone who has needed to add chain.

If you want more (better) advice I suggest you call Pip at The Multihull Centre (01752823900) as he has installed dozens of catamaran moorings in Millbrook

Hope this helps

Richard Woods of Woods Desings

www.sailingcatamarans.com

[GordMay]

Richard & I seem to be using a similar formula. I’m suggesting that the bridle should form something like an isosceles (45-45-90) triangle.
Cleat Spacing distance ÷ root 2
So Richard's: 15' ÷ 1.414 = 10.6 Ft.
Or my 20' ÷ 1.414 = 14.1 Ft
Plus line required to fasten (cleat), etc.

A shorter bridle is often required to reduce swinging circle, on closely spaced permanent moorings. I recommend a slightly longer bridle rope, such that it can be set slightly longer, when used in a more spacious anchorage.

Originally Posted by Woods Designs

I would use short bridles to reduce the swinging room. If your CL spacing is, say 15ft, then I'd use 10ft bridles...
Richard Woods of Woods Desings

[ireaney]

Hi Gord, My intentions would be to have locking carabiner hooks to attach to strong padeyes fixed to either end of the front cross beam (as my mooring situation would always be the same) or have new very strong padeyes attached to the hulls near the cross beam which could double up as attachments for a para anchor etc for use in storm conditions etc.

[GordMay]

For a permanent bridle such as you describe, calculate a 45-45-90 degree triangle, based upon actual distance between fixing points.
Make certain the two legs are the same length, as finished.

[drewke07]

I would absolutely eliminate the carbiners in the mooring setup. the only secure way to attach the ends of tghe mooring line to the boat is to a cleat with chafe protection or with a properly sized and moused shackle to your padeyes

[Strygaldwir]

I'd go with a little longer length.

We currently have a 36 foot overall length on our 22 foot beam. What happens occassionally is that we swing arround and the hull rubs the chain! Wakes my wife up every time. She of course wakes me up with "Whats that!" We'll make it longer and see if that resolves the issue.

[JerryF]

May I ask, why don't you keep the bridal on your boat. Why leave it on the mooring.

[ireaney]

Hi Jerry
The reason to keep the mooring bridle attached to the mooring is one of great convenience, simplicity and to save serious grief as follows:
The rising chain from the ground to the main (mine) mooring buoy (which basically always stays in the water) is very heavy ie to take 12 tons, to which to ensure good holding for the boat the bridle must be attached underneath the main mooring buoy to the top of the riser chain.
As you probably know that also attached to the main mooring buoy (again underneath to the riser chain) is a pick up buoy which would either have a length of heavy chain (in normal circumstances) attached to it or in my case the other ends of the bridle which can be easily attached/detached to fix to the hulls when mooring or departing.
If the bridle was attached to the boat it would mean each time I moored I would have to get into the dinghy after having picked up the pick up buoy and made fast temporarily, and attempt to make fast the bridle to the top of the riser under water and then the reverse procedure for when leaving the mooring, hence why the mooring bridle be attached to the buoy.
I know that there are buoys with rods going through the middle but the safest and strongest way is (as far as I am concerned) is the way above.
My anchoring bridle is a different matter - this would be attached to the boat at all times.

[bill good]

G'day,

The length of each arm=beam. However when moored to a bouy I shorten each arm of the bridle to place the bouy under the front beam to prevent it from banging the hulls, tangles with the bridle & getting under the bridgedeck.

I would take it with me & use it when away at all times.

Regards Bill Goodward

[DHHong Kong]

Bill has it right about the length of each bridle arm being less than the width of the forebeam - any longer than this and the constant banging of the ball against the hulls will keep you well awake.
Cheers

Paul