Running a mainsheet traveller on a vertical face? Will it work?

[Trident]

So I am looking at repositioning the mainsheet traveller for several reasons and it would work best if it could be mounted not flat but at 90 degrees to horizontal - ie on a vertical face - like in the photo (though of course this is fore aft for a jib sheet)

I have a 50 foot catamaran with an 8-1 purchase mainsheet and some big loads - has anyone experience of using a mainsheet traveller in this orientation? I currently have a Harken system and the photo is of a Rutgerson with Roll links rather than ball bearings so I may have to change the hardware unless anyone knows that the Harken might work. ..

I can build a support for a normal horizontal track but requires a lot of welding in situ so if I can avoid it then it would be good
TIA

 

[B27]

The small sizes of Harken recirculating ball cars are used like this on Merlins.

 

[William_H]

I would think instinctively that it would be a bad idea to have main sheet loads on the car off to the side rather than the perpendicular pull they are designed for. It might survive but I reckon you will be unable to move the car under load. ie to dump pressure on main sail by easing traveler.
Perhaps a piece of angle metal to mount track on to set it in proper orientation.
Interesting I would not have thought the jib sheet traveler orientation very good. But at least you do not move it under load. ol'will

 

[thinwater]

If the common track style could work--and that is an enormous if--you would have to redesign the car so that the load was in the same plane as the track. Totally custom. In that way the track is not being twisted. Think shower door track.

But I'd start over with a different idea.

 

[B27]

If you look at the cross-section of the car and track, you'll see whether it's likely to work.
The track and car I've got in my spares box, only the lower circuit of balls would be taking the load if the track was on a vertical face, so you'd probably want to de-rate the car by 50%. If that means going up a track size, it could be pricey.
Harken, Lewmar and others have pretty helpful tech support.

 

[greeny]

Length of stainless steel angle of suitable dimensions would make the job easy and return the track to the correct orientation. Will be cheaper than changing the track and hardware.

 

[Neeves]

But I'd start over with a different idea.

Expand on this.

 

[dunedin]

The traveller is engineered to take heavy loads from above - and along the direction of the track. Not across the track.

You say in post #1 it is on a 50 foot cat with heavy loads on the mainsheet. Surely the answer is obvious from that statement.
The mainsheet on a large catamaran will have HUGE shock loads at times (likely more so than a 50 foot monohull, which can heel to slightly mitigate the loads). This is not the place to make a cheap bodge solution.

And how would you tame the boom WHEN (not if) it breaks - likely in strong wind and waves, perhaps immediately after a gybe. Heading downwind the boom will swing out till it hits the shroud - and then likely break the boom and/or break the stay and bring the mast down. On a monohull if the mainsheet broke downwind a slam of the helm down and pirouette 180 degree slam turn into the wind might be OK - but unlikely to be a good idea on a multihull.

Don’t bodge such a critical component.

 

[Neeves]

I wonder if you are treating a 'cruising' catamaran (you are not racing) like a performance mono hull.

Why not two mainsheets, one on each transom.

Why do you want a traveler at all?

I've been trying to conjure how you can do the same with one mainsheet (but lateness of day and a decent bottle of wine are impediments).

Think of a main sheet on each transom, you tension one and release the other. You do not need a track. Most of the time you will be reaching, its more comfortable than beating into any seas on a cruising cat. You will go faster. You may need to change your destination or ETA. The impact of accidental gybes are minimised as the relevant mainsheet will restrain the boom. You will need to reinforce the location of the block (or blocks) on the transoms and you will need two block assemblies on the boom (for each mainsheet). If you think the tension will restrict trimming put in a fine tune.

If you insist on sailing to windward the transom location of the sheet will give you better ability to trim the main (as a track is so much shorter than the distance between the 2 transoms).

Sailing downwind you will be using the leeward mainsheet.

Jonathan

on further research:

Catana Mainsail Sheeting System ? - Cruisers & Sailing Forums

and similar threads

Sadly my idea lacks originality.

 

[Trident]

I have considered the dual main sheet system as used on Catana but there is so much discussion as to whether the system is as good a traveller for sail shape.

I can make a sensible system to mount the traveller horizontally but it means welding a box section to an in-situ stainless tubular frame over a 4 m length which is a considerable amount of welding , 6 foot off the deck so wondered if anyone had used something like the one pictured above in a mainsheet configuration rather than a jib sheet one (where loads are less)

I suspect a lot of tig welding is in my future

 

[geem]

I have considered the dual main sheet system as used on Catana but there is so much discussion as to whether the system is as good a traveller for sail shape.

I can make a sensible system to mount the traveller horizontally but it means welding a box section to an in-situ stainless tubular frame over a 4 m length which is a considerable amount of welding , 6 foot off the deck so wondered if anyone had used something like the one pictured above in a mainsheet configuration rather than a jib sheet one (where loads are less)

I suspect a lot of tig welding is in my future

I once experimented with such as system for a self tacking jib. It didn't work for quite a small jib. As soon as any load was applied, it would bind on the track.