Tuesday, 13 January 2015

Chafed sheets

It is our third night at sea and we have made very good progress. This part of the Caribbean is notoriously windy and we have had strong trade winds since we left St Lucia; rarely less than 20 knots, gusting up to 30 around the squalls. We spent Saturday and Sunday on starboard gybe, sailing west to keep within the band of stronger wind, then on Monday morning we gybed onto port, heading south towards the headland at Punta Gallinas on the northern Columbian coast.  As I write at 0500 local time on Tuesday morning we have covered 580 miles in 60 hours, averaging almost 10 knots through the water - and that is fast.

One of the great problems of sailing for prolonged periods, particularly at speed, is that ropes chafe as they rub against another surface. If they do this for long enough, even the strongest of ropes will break which can be dangerous if the rope is controlling a big sail in a strong wind. So when I am doing my evening chafe check today I am alarmed to see that the genoa sheet is badly chafed at the point where it passes through the jaws of the spinnaker pole. The genoa sheet is a hefty 16mm diameter rope made of dyneema, with a breaking strain greater than steel, but not immune to chafe, especially under heavy load.

When we are sailing downwind we set the mainsail on one side of the boat and the genoa on the other. To hold the genoa in position we run the sheet through the end of the spinnaker pole which is attached to the mast about 3 metres off the deck, with the outboard end of the pole suspended by two rope guys and a topping lift so that it projects 90 degrees from the boat. By running the genoa sheets through the jaws on the outboard end of the pole it holds the genoa out like a large wing, the main another wing; hence the term Goose-Winged.

The loads on the end of the genoa are significant. The clew of the sail, where the sheet is attached, is subject to the greatest loads and at 25 knots of wind the clew load on our genoa is over two tons. Imagine a rope bearing that much load, rubbing back and forth on the stainless steel jaws of the spinnaker pole continually for 24 hours, and you can understand the problem of chafe. The way to avoid this is to winch the knot at the end of the sheet hard against the jaws of the pole, minimising movement and thus reducing chafe.  When we set up the pole today we left no more than one inch of rope between the pole and the sail, but just enough for it to saw back and forth all day under load, until the cover of the rope chafed through to the dyneema core beneath.  The strength in a rope is in the core but without inspecting it more closely it is impossible to tell whether the chafe has damaged the core. The prospect of the genoa sheet breaking at night under two tons of load, leaving the sail thrashing out of control, is too awful to contemplate so I decide to drop the pole and remove the sheet so that we can cut off the chafed section and tie a new bowline with undamaged rope.

Once the pole is stowed back on the mast, the next challenge is to reach the clew of the genoa so that we can untie and make the repair. The problem is that this part of the sail, even when furled on the forestay, is about five metres above the deck and the only way to reach it is for me to climb the forestay.  We reduce sail to stabilise the boat and I strap myself into the climbing harness and attach the spinnaker halliard. Andrew then winches me up the forestay and when I am in position I look down on the deck below. Fifteen feet below me, the motion of the boat is more apparent and because I am up in the air, the pendulum effect is far greater meaning that i have to hang on to the forestay with one hand and tie the bowline with the other, wrapping my legs around the forestay to keep me attached. I untie the damaged sheet, recover it back to the cockpit and we can immediately see that the core is undamaged. However before we can re-end the sheet we have to ‘milk’ the cover along the rope to ensure that the cover is evenly applied along the length of the sheet. Using a hot knife we then cut the damaged section off and I go up the forestay again and tie on a fresh knot to the clew.   The repair made, we reset the genoa, ensuring that the knot is snug in the jaws of the pole and off we go again, running downwind towards Columbia.  The only real consequence of this incident is that our evening sundowners are delayed and we sip our drinks as the sun sets on an eventful day.

As I write this on my night shift, I see from the log that at around midnight the wind was gusting up to 32 knots and Fatty put another reef in the genoa. During Kerry’s watch a large tanker passed within a mile of us so she had to alter course to give it a wide berth. We are now crossing the shipping lanes so we have to keep a good look out as tankers, cargo ships and cruise liners head north and south, down to Venezuela and up to Panama and the USA. The wind occasionally gusts up to30 knots and even with two reefs in the main and the genoa, the speedometer briefly touches 14 knots as we charge through the night on our way southwest towards Santa Marta. Down below it feels quite dramatic as the movement of the boat and the sound of the sea rushing past is amplified through the hull.  Sleeping isn’t easy in these conditions as each wave that passes under the hull rolls us around in our bunks, making for fitful sleep and wild dreams.  However up in the cockpit it is a glorious night with a half moon illuminating the sea and lighting up our wake as we surf down the waves. I reef the mainsail further to slow our speed a little.

With 230 miles to run, at our current rate of progress we should be in Santa Marta by Wednesday morning, just in time for lunch.


  1. You're like Ellen McArthur - go Frew!

  2. Always impressed by your knowledge and ingenuity in sorting out kit and chafed sheets. Sounds great and fast.

  3. Go for it Bertie - you look a natural !!!