Dumb question

[Ed_Shannon]

Hi Brion, I’m hoping that you’ll indulge a novice sailor and answer a question that’s stuck in my head. Here goes… why is it that when I loose the windward clutch on my traveler the car doesn’t immediately slam to the leeward side? There is tremendous wind pressure on the sail and therefore on the boom so it seems to me that it should simply push the traveler car down the track. Is it simply that the upward pressure exceeds the lateral pressure or what?

[Ian McColgin]

Presumably this happens right after you've tacked. You've about got it. Modern rigs put a lot of down strain on the boom - upstress on the traveler - as you can see by the angle of the sheet. Envision the paralleogram of force with imaginary vectors normal and in line with the traveler and the net vector being the sheet from the corner down at the traveler up to the boom. Unless you have lots of powerful bearings in the car, it will naturally bind until some shake or whatever breaks the static friction.

I so rarely actually pull the traveler to weather that I like to set stops and let the traveler find it's way without restriction from one side to the other, which it will easily do as the sail's luffing somewhat unloads the verticle vector of the main sheet.

It's rare but sometimes even my old gaff cat Marmalade finds the verticle component so strong that the shackle on the sheet block won't at first slide down the horse when we tack. But really, for that boat it means I've oversheated pretty seriously.

G'luck

[Brion Toss]

Hello,
It is true that when the loads are highest (on the wind, in a breeze) the load is primarily vertical, and that can make it hard for some cars to slide to leeward. And on some boats, like maybe Ian's, positioning the car isn't critical. For instance on a gaffer, you pretty much want to have the car on one side or the other, to minimize leach twist.
But on most contemporary boats, that traveler is a precision instrument, and you should be able to put it where you want it, when you want to; it can have that much of an effect on sail trim and helm balance. So if yours won't go to leeward on its own, something is very wrong. Remember, even on the wind, at least 20% of the sheet load is expressed laterally, so if the bearings are remotely efficient the car should move easily to leeward. And given enough purchase it should also be easy to take uphill as needed.
If this isn't happening, you can hope that the bearings simply need cleaning and lubricating. On a Harken car, or any other with exposed Torlon bearings, that means a little soap and water, then some "One Drop" oil from Harken on the bearing races. But it is also possible that you simply have a crappy traveler. If that's the case, get a good one. The difference will be profound.
Fair leads,
Brion Toss

[Ed_Shannon]

I didn't have an operational problem, it was more conceptual. I didn't understand what held the traveler car still when the windward line was unclutched. I didn't appreciate the vertical force involved. My boat, a Catalina 36 MKII has a 6:1 purchase on the car and it is not a problem to move the car in either direction.

I understand now. Thanx. May the force be with you. Ed