Stone Sailing Club is on the River Blackwater, Essex. The club’s moorings are administered by the St Lawrence Fairway Committee which leases an area in the bay from the Crown Commissioners.

Sadly the local tug owner passed away. Because the lifting and laying is the responsibility of each individual owner, we gathered together as a group and through the medium of the club and the Fairway Committee elected a harbour master, a cruiser class captain, and we have a chandler (me) who buys the tackle in bulk to assist owners in setting up and laying their moorings.

The solution to laying ground tackle

We invested in a large air bag manufactured by Unique Seaflex on the Isle of Wight – they’re used all over the world for things such as salvage and lowering pipelines onto the seabed.

We bought a second-hand 3-tonne capacity bag for £960 (Seaflex will rent them for short periods but we were confident we’d get a lot of use out of it).

Moving one of the smaller moorings with ground tackle with a tractor. Credit Sam Longley

The bag is inflated to a pressure of 2lb/in2, done with a simple air blower. It also has a deflate facility so the air can be sucked out of it for storage.

The idea is to place the sinker, complete with mooring tackle, at the low tide mark using the club tractor.

We attach the airbag to the mooring weight via a release mechanism. A release mechanism might, at first instance, seem simple but before we bought the airbag we did a test with a sinker hanging from the tractor and soon realised that 3 tonnes was not so simple to drop.

We did several experiments with mechanisms, modifying and improving them in use, and now have it about right.

Detail of the release mechanism for detaching the air bag from the mooring ground tackle. Creidt: Sam Longley

We’ve purchased a 20ft work boat which we use to tow the air bag and sinker into position. The setup is connected up on the beach and when just about to float off we motor the launch in and pick up a line and pull the whole lot off the shore.

To aid steerage we tow on a long line; only pulling the timber release pole in close at the last minute. The timber has to be as long as possible otherwise we’d have no steerage at all and the propwash would just hit the airbag, stopping us dead and leaving us at the mercy of the 3-knot tide.

One end of the rope is then released, and we all keep our fingers crossed that we did it in the correct position and the rope does not snag.

Release mechanism

For really heavy sinkers (3 tonnes weigh 1.77 tonnes when in the water) we started with a pelican hook pattern, but the long hook caught in the links of the chain stopping the sinker from dropping cleanly. Eventually we went with a swinging arm and a support bar.

To release this, we needed something to allow it to work 2m below water level and 3m away from the boat.

Turning the crank bursts the cable ties to release the sinker. Credit: Sam Longley

We needed the whole lot to line up with the towing launch so a swivel arm was added with a pickup buoy so we could gather this when the airbag was ready to collect.

To stop the hook unit opening accidentally we fasten it shut with two cable ties. A line is attached to a winch on the end of the timber. When tightened, it bursts the ties, opens the arm, thus releasing the sinker.

Everything set up waiting for the tide to come in. Credit: Sam Longley

We have successfully placed many of our moorings and if we have an application for a mooring mid-season we don’t have the expense and waiting time of a tug, but can just place one within a few days.

■ Ed’s note: Sadly, Sam Longley passed away before he could see his article published, but with his family’s blessing we are sharing this, his last practical article.

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