2 Feb 20124
Another slightly breezy day – but that doesn’t seem to stop as many people these days. While Mervyn and Peter C watched from the clubhouse and we had three Solos on duty (Mark, Ian and Tony S) we still managed a decent turnout for the pursuit with 7 boats on the water. It must have been right on the edge for Dave C but all finished which is really quite impressive.
So the course if I recall right was 7,6,3,4,8,F,2 which was beat, reach, run, tight fetch (I always made it in one tack but some boats didn’t), close reach, broad reach, broad reach. Never really looked an ideal Solo course with long close reaches where the faster boats might start to plane but we couldn’t, although the run was very good meaning the asymmetrics couldn’t do it without lots of gybes.
Last week we covered a lot about going to windward in strong winds. This week it’s time to think about the other legs… what do we do on a reach or a run in strong winds. Much of this will be familiar to the more experienced sailors but perhaps not to some. When we are beating and we get a gust we luff slightly to make the sail spill a bit. We do NOT do this when reaching and especially not when almost running. In fact we do the opposite. We bear away a bit when the gust hits to run with the gust but to do that we must also ease the sheets and keep the boat very flat. When a gust strikes on a reach we ease sheets, bear away and lean out more. Why do we do all that – several reasons – bearing away will tend to bring the boat upright because you put the hull back under the rig. Going to a broader course reduces the side force from the wind (when you get to a dead run there is no side force), and because we can then take more of the sails power (it is pushing us more forward and less sideways) we can accelerate. Once the boat has accelerated it actually becomes slightly more stable and we can usually start to point back towards where we want to go. In lulls we point up a bit, in gusts we bear away a bit and we adjust the sail all the time to keep in matching these course changes. Above all we keep the boat flat. if we let the boat heel we cannot bear away and run with gust. reaching I take the mainsheet from the boom because that’s more responsive than through the jammer (the more horizontal pull gives better leverage so in most conditions I can take it from the front pulley (2:1) but in very strong conditions I just take it in hand before from the boom on the last purchase before the jammer.
OK that’s the basic sailing, but what about the rig. We had lots of Cunningham and kicker on upwind to flatten everything and let the top feather. Now we are easing the sheet and can start to take more power we want to put some shape back in the sail so we can ease the Cunningham, ease the outhaul and ease some kicker to allow the top of the sail to twist a bit. If we are still very overpowered we can let the top twist a bit more and reduce the knockdown on a reach.
Now we get to running. This is where the fun starts because we have what is basically an unstable situation. You have to keep the hull under the rig. The problem is that it is unstable.
- Start to heel to leeward and the boat starts to luff – that makes the boat heel more, the wind pushes the rig more sideways which makes you heel, the boom hits the water which stops the sail going out and slows the boat which increases the sail power… a vicious circle or forces and you capsize. This is called broaching. It is what happens after a gybe if you don’t stop the boat turning.
- Start to heel to windward and the boat starts to bear away which makes the boat roll more to windward which makes the boat turn faster and … splat you are in the water with the boom sticking up in the air and you weren’t even able to climb over the top. It is probably the fastest capsize you can get because the power is all still in the sail all the way. It feels like the boat trod on a banana skin. Called weather roll or death roll.
OK so we know what happens – how do we stop that. The answer is that you have to be quick. Mainly it is about steering, literally steering the hull back under the rig - stopping he boat turning and in fact forcing back a bit the other way but that only works if the boat hasn’t already heeled too much. There are other things you can do to help. If the boat starts to heel to leeward ease more sheet if possible (before the boom hits the water). If the boat heels to windward sheet in quickly – that changes the sail angle and stops the death roll – in very strong winds running I have the sheet in hand and keep the boat balanced with the sheet steering as necessary. Sometimes you have to steer more because the gust came from a slightly different direction but the reactions are the same. Heel to windward push the helm to resist bearing away. Start to heel to leeward pull the tiller a bit to bear away and run with the gust.
Ideally the boat should be perfectly balanced so that it doesn’t want to luff or bear away – how can we control that? Two things – correct centreboard and correct kicker. Too much plate up and steering doesn’t work and you weather roll. Too much centreboard down and the boat easily trips over the board and broaches. Down also means forwards which increases the tendency to luff. Up more brings the plate back and corrects this – but always leave enough down that the boat still steers easily – about ¼ down or a good foot sticking out underneath the boat.
Now we come to the really important one – the kicker. This is what balances the sail on a run. Too little and the top of the sail angles forwards which means the top of the sail generates a side force to windward and starts the death roll. A big gust will push the top of the rig more forwards as well. Too much kicker and the back of the sail is still tight and the boat wants to luff – this tends to make the boat broach and also means the boom hits the water more easily.
Putting all that together means you must know how much you can let the kicker off on a run to have balance. If the boat feels as if it keeps wanting to roll to windward add a bit more kicker. Some boats need a lot more than others – Paul’s old boat (now the red wooden club boat) seemed to need more kicker to be stable. Initially you stop the roll with push on the helm (resist the turn downwind) and pull on the mainsheet – bring the boat back upright. But if it is very twitchy add more kicker. There isn’t time to add kicker when the roll happens, you have to use the mainsheet first, but then adjust kicker after the immediate danger is over.
This whole sequence takes practice – it is very easy to over correct – much like a car skidding – it takes practice to control a skid. It takes practice to catch a weather roll. It is worth trying on a medium day running and letting too much kicker out. you’ll feel the boat want to roll – sheet in and stop it. Then tweak the kicker until the boat wants to just sail straight without rolling either way. Note the setting. In stronger winds you will need a little more but now you have a guide point. In light winds you ca let a lot more go.
Oh – the races on Sunday – results from the morning were (pursuit positions in parentheses)
Gareth (7), Paul (8), Tony P (14), Peter H (15) Ben (17), Roy (20), Dave C (21)
On duty Ian, Tony S, Mark.
Although Paul and I were 7th and 8th we weren’t actually overtaken until the last few minutes. The pursuit worked out about right.
In the B2B races we had some really close racing again with at various points in the races the first Solo being Tony P, Paul or Gareth including Paul being ahead right to the last mark in one of them. There’s a topic there about how to defend when someone else gets an overlap but that’s one for another day, and a reminder about keeping loose cover upwind…
Forecast for Sunday looks pretty windy – we seem to be in that sort of a pattern at the moment but at the moment it shows dryish and the last forecast I saw was slightly less strong so come down and see – if it IS that windy, watch the maniacs who go out and see how they sail…