The Power Sequence

“ Boatspeed makes you a tactical genius” ,how many times have we all heard the old saying. Great and all that, but how do I get some ? One of the beauties of our sport is that you will always find yourself striving to sail the boat quicker in a straight line, no matter how much sailing you do.

Careful rig tuning, calibration, meticulous boat preparation and recording settings will all help you go quicker but at the end of the day getting the sail controls set correctly will make as much, if not more difference than anything else to your upwind boatspeed.

This article intends to help our understanding in how and when we use the sail controls to effect the sequence of power control.

The simple sail controls such as the Mainsheet and Jib sheet, the Kicker (vang) and the Cunningham control the amount of twist in the sails and this is the main power button. In order to get the most out of your rig tuning and equipment it is essential to set these to achieve the desired leach shapes for the day.

The amount of twist required for each day will vary a lot. Twist in the sail helps the boat to accelerate so as a general rule if the boat is getting slowed down by big lulls and or waves you are likely to require more twist than a flat water stable air day. With practice you will get an understanding for how tight you can sheet the jib for each condition and you should aim to know where the leach should be on the spreader if you want the sail to be closed or open. It is very rare that the boat will want to be set up with a tight jib leach and open main or vice versa, if this is the case something major is wrong. The two sails should always be balanced.

We view the power from the sails in a series of stages, as discussed the power from the sails is effected by how we use the controls.

For the mainsail the main course controls ( the kicker and Cunningham ) will follow a similar sequence in all types of two person dinghy. Initially we are looking to get as much power as possible from the mainsail. To do this we use the mainsheet to provide the leach tension and just take up the slack with the vang. Tensioning the vang simply bends the mast and flattens the sail. As we get to the 2nd stage we will continue to hold the leach tension on the mainsheet but are likely to have to use a little vang to stop the boom rising. Between stage 2 and 3 there will be a change-over period and one of the hardest times to make the boat go fast is when you are in between these windspeeds.

STAGE	MAIN CONTROL
1	Mainsheet tension only
2	Mainsheet and vang taken up
3	Boom always off centre, vang only
4	Max vang, fully powered up
5	Overpowered, Cunningham on
6	Max kicker, Max Cunningham
7	Still overpowered, kicker ease

Stages 4 and 5 would be our perfect working area. If we could we would have the boat set-up in this mode all the time. This is the time when the boat starts to plane upwind and is in it’s fastest range. Stage 6 and we are starting to get to the top of the wind range on the rig setting we are on ( in this case our light air setting .)
The jib leach will now begin to be eased by quite a bit and the Cunningham has been pulled as hard as you can ! From now onwards the boat will almost slow down in the gusts, by easing the kicker in the gusts the boat will be allowed to continue moving forwards fast and not get slowed by the leach causing the mainsail to flog.

The shape of the leaches go from their tightest in the 2nd and third stage through to it’s most twisted in the last stage.

I Would suggest that it is time to go to stage 5 ( cunningham on ) when the boom is coming off the centreline by about 2 feet on an fully battened main ( little more on a conventional dinghy), or when the mainsail is backwindng a lot. Similarly you would be looking to start easing the vang when the main is back winding constantly in the gusts. In some boats easing the vang doesn’t help de-power the boat. This is usually when the boat does not have a very powerful Cunningham ( 420, Enterprise ) and in these boats you may accept more mainsail flogging or go to your next setting slightly earlier.

The Jib set-up should follow a very similar sequence. The amount of twist in the sail should highest at the 7th stage and at it’s tightest between stage 1 and 2. Some boats will have movable jib cars. Generally reference your tuning guide for where to set these but the jib will want to be at it’s deepest in stage 2 and it’s flattest in stage 7.

As an overview we will tend to try and power the boat up as much as possible until we get to stage 7. Once you reach that point then it is time to move onto your next rig setting. This may be to rake the mast back more or to tension the rig more. You may have chocks or lowers as well but it is important to consider the power sequence first before changing rig settings and understand where you are and what is the next control line to pull. It is also worth bearing in mind that each rig setting should end at stage 6 or very early in stage 7 and start at stage 4 or 5. Obviously this isn’t possible in the lightest of winds.

Some simple advice would be to calibrate you control lines, try and calibrate your jib sheet, then you will find the points that are max vang say and the tightest jib setting, then you can reference back to them and apply them to your settings guide. Ask the people who wrote the settings guide how they used the controls around the settings and finally don’t be afraid to experiment !

CD

See the 49er settings guide

49er settings guide