I don't understand the traveler design - please 'splain it to me

Thread starter #1
So I was sailing around the other weekend and got to staring at the traveler - and it seems fundamentally broken to me.

The point of a traveler, as I understand it, is to fix where the boom sits relative to the centerline of the boat when it's block-to-block. That is, I believe when the traveler is fully tightened down and you sheet in all the way, the boom should be smack in the center of the boat.
Then, the beauty of the traveler is that, if weather and sail conditions dictate it, you can ease the traveler off and let the boom out a bit toward the leeward side while still maintaining the shape of a fully sheeted-in sail.

The dual-pulley system on the Laser allows the boom to always slide down and point toward the leeward rear corner of the boat regardless of how tight you pull on the traveler line.

reference pic (Thanks, APSltd.com!): http://imgur.com/KYK2u

I retied mine to take the bottom block out of the picture - so the top block is just fixed to the traveler line. Now, when I pull the traveler in, I can get the boom all the way to the centerline of the boat. When I let it out, it can ease down toward the corner of the boat.

I'm sure that I'm just radically wrong in this somehow - probably in my understanding of what a traveler is for - but I don't get it. heeelp!

Oh - btw - I don't race so legality is not a concern for me - though it might be interesting to know if rigging mods like this are legal if someone wants to chime in on that.

Thanks!
 

jeffers

Active Member
#3
The idea of the traveller on the Laser is to always sail with it as tight as you can (so the blocks just get over the tiller).

As the boat is una rigged you do not want to centreline the boom, the is slow and make the boat very unstable.

Ideally the back end of the boom should never come any further inboard than the rear corner of the boat.

As for design I am with gouv on that....it is a bit of a joke!
 
#4
On bigger boats the idea of the traveler is to adjust the sheeting angle to effect the downward pressure on the leech of the sail (directly effecting sail twist further up the mast). Therefore it allows you to be close hauled without the mainsheet pulling the boom down.
Not two sure you would ever want the boom to come as far as the centre line of the boat as this would mean the power from the sail would be perpendicular to the direction of travel and you would go sideways or most likely just trip over your centreboard and end up in the drink.
As I said this was the idea on bigger boats, from some of the of the 'classic' dinghy's I have sailed, Enterprise, GP14 the earlier 1950's 1960's boats seemed to have a traveler that was adjustable (you could bring the mainsheet block up to windward) however this has become less and less a requirment where most newer Ents I see just have a traveler which slides to leeward on a track (the more modern GP14 has a fixed rope traveler attached to each corner).
There may be something to do with the Laser also having an unstayed rig where mast bend is inparted somewhat by the mainsheet (and kicker) when close hauled so this may change things slightly. Also as the Laser isn't a true centremain the pull from the main block (on deck) to the first block, mid boom has a large effect on the sheeting angle, pulling the boom into the middle of the boat. (For true centrmain boats I am thinking of Finn, Byte, newer Solo' where the mainsheet block sits on a sliding track and there is no sheet attached to the transom)

Interested to see what other people think........
 
#5
If you think of the mainsail on the laser as a jib it makes a bit more sense. You would never sheet a jib to the middle so you wouldn't do it to the laser main either. The best position is with the boom pointing at the corner of the transom (any closer and you start going sideways fast). This is why people try and get the traveller as tight as possible because if it is loose it will ride up into the middle.
You can keep it there by using the kicker but that bends the mast and you lose power (OK for windy but not fast in medium/light breeze). Therefore you want to be block to block on the mainsheet with the blocks in the corner of the transom (traveller as tight as possible).
This is where people start getting carbon tillers (lower and flatter) and kevlar traveller lines (less stretch).
 

jeffers

Active Member
#6
Only kevlar travellers are not class legal I believe as kevlar is an aramid fibre (which I seem to recall is not permitted by class rules...AlanD care to verify or correct this statement?).

This is not some draconian Laser rule it is common sense, aramids do not like going round corners, especially sharp corners like on a Laser traveller... They will be fone for a while and then part company without an prior warning.
 
#7
Don't have kevlar on mine (as you said it breaks without warning) but just checked the rules and it's the kicker and cunningham they are not to be used on.
 

AlanD

Former ISAF Laser Measurer
#8
Aramid fibres are permitted for the control lines, except for the vang and cunningham. It's a fairly moot point these days, aramid fibre ropes aren't widely available these days, they aren't as strong/low stretch compared to some of the other ropes, plus they aren't designed for going through tight radii (the old quoted figure was that anything tighter than 10x the thickness was too tight).
 
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