1 (edited by bertinol 2014-01-13 04:50:48)

Topic: Swing moorings

We're currently updating the swing moorings at our club in Lake Ontario.   

One question that has arisen is: How long should the mooring pennants be?  That is the line from the mooring buoy to the bow cleat.

Some people argue it should be twice the freeboard plus the length from the fairlead to the cleat.

Some want longer lines to give an easier ride in stormy weather; some want shorter lines to limit the amount of swing.

Any good ideas? The water is 12 feet deep. No tides, currents or significant waves, but we do get high winds.

Re: Swing moorings

Possible answer:  We had our boat on a mooring in Hamilton Harbour (at the Burlington club) all though the 70's and 80's.  The conditions would have been similar to what you describe and worked very well.  The moorings were maintained by the Hamilton Harbour Commissioners - you could contact them and ask what they do as I'm sure they've got them down to a science by now.

Re: Swing moorings

Preallocated moorings or first come first served?

If they are preallocated, then let the user choose the length subject to an overall length limit (of boat + strop from stemhead).   What suits a Co26 owner wont suit anyone with high topsides and if the strop is too short it can get very difficult to pick up in a blow, possibly leading to an out of control boat in the mooring field.  Short strops *will* need pickup lines and buoys

If they are first come first served, consider long strops without eyes so they can be cleated off to suit, with a whipping on to indicate the max length from buoy to stemhead that *MUST* always be inboard.

4 (edited by bertinol 2014-10-31 12:38:15)

Re: Swing moorings

Many thanks Deb and Ian.

We put a lot of thought into the swing moorings -- pre-allocated, Ian, and permanent.  They have been there for 30 years at least and work well with minor changes every year. For those facing similar decisions, here's what we do:

The water is 12 feet deep, sitting on mud, with limestone about 20 feet down. No tides; we're spoilt. We have a collection of steel railway wheels that weigh about 700 pounds each that sit on the bottom with a welded rebar yoke, a heavy, high-tensile u-bolt and a heavy chain. At the top of the chain is a car tire or, lately, a round mooring buoy that is topped off with another u-bolt. You need a crane barge to install these railway wheels.

We tried hard plastic buoys last year but the ice destroyed 3/4 of them.  They sank. The round mooring buoys and car tires survive longer but they do sometimes leak and then sink. The cause is usually easy to find: propeller slashes from a passing motorboat.

We use a variety of mooring lines, depending on the whim of the owner. One of mine is 5/8 inch with a spliced loop that I can pick up and loop over the cleat quickly. The other line is 1/2 inch and long enough to tie around the mast in a hard blow. I have whipped red thread around the 1/2-inch mooring line at the fairlead so I can adjust it to the right length quickly and easily. I use a 1/2-inch line because it is more flexible that 5/8 and perfectly strong.

The lines are generally twice the height of the freeboard plus the length from fairlead to cleat. Some prefer shorter; I like longer because the boats bobs more comfortably. I install net floats on my line to make sure they float up and away from the mooring chain. Without the floats, the lines will sink and twist around the chain, rip on the mussels and cause endless havoc. I know; I've been there. 

We have about 60 of these moorings behind a seawall and they work well. They do, however, need checking about once a year, a job for a volunteer scuba diver. The main wear point is, surprisingly, about a foot off the bottom, probably because sand and grit work on the chain where the wave action moves it most.

The annual checks are important.  Chains have been known to break. But the more serious problem is the reluctance of some owners to safety wire their shackles. We check the lines every morning, an important precaution.

Why swing moorings instead of docks? I love them. The boat bobs nicely with the wind, I see ducks and geese and egrets and turtles and fish. I'm not bothered by my neighbours on the next dock and the boat handles waves and wind far happier than at a dock.