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STOPPING THE FLOP

Or Roll damping.

 

"Are you being rude" she replied, to my offer to make a 'flopper stopper' for her yacht. A few days later single-hander 'Mo' Jenkins calmly mentioned on the British maritime mobile radio net, that her yacht 'Lucia' was laid to anchor, with a 'flopper stopper' rigged.

That nearly caused a radio riot! Everyone thought it was hilarious, one guy even explaining that in America that was a piece of ladies clothing!

While I was making it the couple on the yacht next to me, with over 80 000 sea miles between them, asked if it was some kind of sea anchor. When I explained what it was they disbelievingly asked if it would really work as they had never seen one.

I discovered the flopper stopper 30 years ago when I moved to Bideford and started sailing in the Bristol Channel. The open anchorages at Clovelly, Lundy Island and along the Welsh coast are notorious for making the yacht roll at anchor. Often a beautiful weekend's sailing would be spoilt, due to lack of sleep in the anchorages.

Like many other sailors I tried hanging a bucket in the water off the end of a boom. Didn't work, we still rolled. The next idea was to lay a stern anchor in an attempt to stop the yacht laying across the waves. Didn't work. Even became dangerous once when the wind changed and I needed to change anchorage.

Having spent yet another sleepless night anchored off Lundy and getting desperate the thought that next occurred was, does Hiscock mention this problem? Yes he does. Looking in the index, I found 'roll damping'. Quoting the great man he says:- 'To reduce rolling in an anchorage subject to swell, roll damping gear ( a flopper stopper ) can be improvised.'

The photograph that went with the text showed a triangle of wood, with a rope bridle attached to each corner and a stone tied under one corner. The idea is to hang this into the water, from the end of a spinnaker pole rigged on one side of the yacht. As the yacht rolls towards the device the ropes go slack and the weight makes it dive. As the yacht tries to roll the other way, the ropes become tight, the plywood becomes horizontal and resists being pulled up through the water, damping the roll.

I've got to try this I thought. I found a suitable piece of 1/2" ply in the fore-peak, this was quickly cut to shape. Holes were drilled. A couple of pieces of scrap steel bar were lashed on as weights. The bridle was fitted by drilling holes in each corner passing the rope through the hole and knotting it underneath. 

I didn't have a spinnaker pole so I swung out the main boom with this hanging from the end. It was like magic!!! 12 tons of steel Spray that would sometimes nearly roll the scuppers under, suddenly sat totally docile while yachts all around rolled like pigs.

I was totally convinced. Since then I have had other yachts and I always make a 'flopper stopper' for them. Cruising in places like the Bristol Channel, Azores, Canaries and Caribbean islands, where you are often in open anchorages sheltering behind islands, having a flopper stopper is a great help towards a comfortable life. 

CONSTRUCTION

A roll damper can be made from any flat,  stiff, strong material. Normally 1/2" ply is used. My most recent ones were made from 1/4" scrap aluminium. A piece of scrap steel plate could be used, but would be heavy to handle and rust badly.

This is cut into a triangle and the following sizes seem about right:- Each side of the triangle will be about 20" for a 25 foot yacht. 26" for a 35 foot yacht. 36" for a 45 footer.

If made from wood or any other material that floats, a weight must be fitted in the centre heavy enough to make the board sink. ( not needed if made from metal ) Another weight is fixed to one point so that the board will dive when dropped in the water.

A 6 feet long, three legged rope bridle goes to each corner, either through a hole and then knotted, or a 'U' bolt is fitted to each corner and the bridle tied to them. A single rope goes from the bridle up to the end of the spinnaker pole. This should allow the board to hang about 6 feet below the surface of the water.

The longer the pole, the greater the leverage, the better it will work. So if you have an extending pole put it at its longest setting.

A piece of scrap ply, some scrap metal weights and a few off-cuts of rope make a flopper stopper the most inexpensive comfort aid you'll ever get. Once you've tried one you'll be like me and never sail without one!

 

 

 

Paul Fay 2001