Mainsheet track

[tyce]

I am going to fit a mainsheet track to my boat, to get the best for performance should i have the track the full width of the cockpit, or would just between the seats do the job.

any suggestions for a good track would also be appreciated.

 

[VicS]

The longer the track the better the control you will have of sail shape.
A track across the front of the cockpit will also be more effective than across the back of the cockpit but will require a more powerfull sheet system and is always an inconvenience and a hazard to the unwary

 

[sarabande]

The wider the track, the more opportunity for control of sail shape, as VicS has said.

It might be worth considering where your crew place their paws or bums in relation to the track, as the traveller can slam across a track unless it is properly controlled by stops or a cleat system.

 

[shmoo]

Our mainsheet traveler is known as the "finger biter".

Get one that locks positively in place and won't secretly unfasten in a bit of head-to-wind boom wobble and then lurk ready to take off someones fingers as it slams against the end stop when the helm bears away.

 

[aknight]

Not certain, but I infer from your post that currently you don't have a mainsheet track at all - the mainsheet is led to a fixed point on the cockpit sole? I had that arrangement on my boat but this year upgraded to a track as shown below:

As you can see it is well forward in the cockpit (but still within reach of the helm). This seems to give better control, although it was necessary to drill out the old attachment point on the boom and move it forwards to match the new track position. Due deference to those recommending above that you go for a full width track, across the seats as well, but I have found a significant improvement even with the modest width of track shown above as against the former fixed block. Siting the track on the floor avoids trapped fingers, and angling the control lines slightly aft brings them well within reach of the helm.

 

[Fin]

Control

How much do you want?

The wider your main sheet traveler the more variation in the way it pulls on your main.

The "ideal" kicker and mainsheet setup is to have a semicircular track based on the length of the boom with the base of the mast as the center. Set the sail to the conditions and then adjust the traveller for the power or angle of attack. With this set up the tension on the main will not vary with the tension on the traveller. When the main sheet is dumped the top of the mainsail will open rapidly and depower the sail. With a wide straight track if you dump track instead of main.......The top of the sail actually tightens as the the track gets further from the ideal.

The sail with a wide track and fixed main will actually power up at the top of the roach as you dump track in a gust.

If you are not sure of what I mean then imagine a vertical look down on a mast and a boom. A semicircular mainsheet and kicker will never change the downward tension of the sail.

This is why on a lot of racing boats the designers do not suggest a full track mainsheet, if on a wide sheet boat you dumped a lot of track in a gust you could be tightening the pull on the main just when you want to be reducing it.

If your track is short then it's not really an issue, you have more to gain or lose upwind from your mainsheet tension than tarting around with your track position.

This is all IMHO.....

Coops

 

[aknight]

I can see the logic in what you say, but there are other considerations, surely?

First, there is the question of ergonomics. In a small cockpit, siting the mainsheet traveller further aft or as a curve may simply interfere with the helm to an unacceptable degree. It may just be that I'm used to having the traveller set forward in the cockpit, as it has been on all of my boats, and so have become comfortable with it, but it's always seemed logical to me for it to be sited there.

Second, while I can see your point when it comes to dumping the main, that's a question of use not design in my view. You always have the option to dump the main without letting off the traveller. In fact that's what I always have done to depower in gusts, it wouldn't be instinctive at all for me to dump the traveller.

Finally dumping is one thing, but what about the opposite situation, sheeting in when working upwind? That's when I most often use the traveller, to keep the boom positioned in such a way as to get the slot between main and foresail functioning as best I can. The old, fixed attachment to the cockpit sole did not allow me to do that very well if at all - the new arrangement works much better.

 

[tyce]

Thanks all for replys, yes the current set up is just to a fixed point on the cockpit sole, which when you think about the pedigree of the boat seems a stupid set up, the plan was to attach the track to the step at the front of the cockpit so it would make no difference in awkwardness terms if it was full length or not, so its probably looking like full length is best.

 

[aknight]

My previous boat, a Varne 27, had the same arrangement - it worked fine and, as you say, once you got over the inconvenience of it crossing the companionway, it might just as well be full-width.

As an engineer you probably don't need reminding, but you should give some thought to how the traveller will be controlled if mounted in that position. Control lines can be led aft to be within easy reach of the helm, but setting up the leads can be tricky if the angle from each end of the track to a locking position aft is too acute.

The arrangement on my Varne dispensed with lines and simply used movable slides, tightened by wing nuts, which you set in the position in which you wanted them to hold the traveller. This arrangement would have been easier to fit by whoever did it, but essentially required you to leave the helm to move the traveller. Not really a problem when dumping the main in gusts, as that should as explained previously be done with the mainsheet, which can still be reached by the helm if you make the sheet long enough for some slack line to be laid aft. But still a bit of a pain for upwind work, when the helm might not feel able to leave the tiller in order to set the traveller correctly. Whether this bothers you depends on how much of a 'sail-tweaker' you are...I liked the arrangement chiefly because it seemed well-chosen to prevent the traveller slamming across on the fingers of anyone climbing out of the companionway, whereas a control line could always be released (or release itself) at the most dangerous moment.

Moving the traveller by hand rather than by control lines, incidentally, was physically undemanding on most points of sail. That said, control lines (properly set up) will always give you extra purchase when the loads build up.

 

[Fin]

Problem only really arises when you start having a wide cockpit with a full width track. Most boats that have them, will have stops put in to prevent the traveller using the full width. I've only seen semicircular tracks on boats with lots of carbon fibre but they do look good in black.......

I tend to use the mainsheet tension to set up the ideal sail shape and then use the traveller to dump power. By lowering the main down the track you quickly reduce the angle of attack of the sail and get rid of a lot of power by feathering the main. When the gust passes it's quick and easy to pull the traveller back up again and you are straight into the perfect sail shape.

To be honest its what works best for you and your system. For a lot of people its easier to dump main than traveller.

Have fun!

 

[Slowtack]

My last boat had a Harken windward sheeting traveller - excellent.

 

[DaveS]

That's a very interesting point, I hadn't thought of that before. Presumably it only applies if, when centred on the track, the sheet is vertical.

For reasons more to do with clearing the sprayhood than optimum control, I moved my boom attachment point a bit further back, making the sheet about 10 degrees off vertical when centred. As the car moves away from the centre, the sheet becomes more vertical rather than less which effectively lets out rather than pulling in the sheet.

Have I inadvertantly solved a problem I never knew I had? /forums/images/graemlins/smile.gif

 

[Dipper]

One point not yet mentioned is that with a full length track you can help to reduce the forces involved during an involuntary gibe when running downwind in a blow.

Earlier this year I was crossing Lyme Bay dead downwind in a Force 6 gusting 7. The mainsheet track was fixed as far to leeward as possible with the sheet relatively taught. I had fitted a preventer to the boom but just as my crew was emerging from the cockpit I lost concentration, the mainsail backed violently and the preventer snapped. The boom slammed across and stopped millimeters from my crew's head. Although it did actually hit him, it had virtually stopped before it made contact. Without the long track, the boom would have carried on with great force possibly causing a serious injury.

Having a long track also allows you to stop the boom lifting in these circumstances - in conjunction with the kicking strap.