Why not an arch and no boom?

[Mrnotming]

With these modern dart shaped on deck yachts, is there any need for a boom at all especially if furling main is a feature.Seems one could simply do without the boom mostly and outhaul from the quarter if off the wind?
The Legend USA yachts used to feature a sturdy arch for sheeting the main, does this not obviate the need for a main boom?
What do the forum think?

 

[Rossynant]

Sheeting angle. Without the boom you only get sail at angle from tack to sheet block. Fixed. Like on a jib, always set for close-hauled (this gets sometimes forgotten - but you only can make it fuller, angle remains) so never work properly off-wind.
To change the angle of incidence to the wind boom is necessary. Unless the boat is reeeeely wide, as cats.
Sailed with boomless main though, but this had gaff

 

[Daydream believer]

Sail require a number of adjustments at the clew, - outhaul, reef points( unless in mast furler which gives poor shape anyway), flatteners etc so a single point would not work
On the run there is nothing to hold the mainsail out & down & still get these adjustments

 

[Tomahawk]

Sheeting angle. Without the boom you only get sail at angle from tack to sheet block. Fixed. Like on a jib, always set for close-hauled (this gets sometimes forgotten - but you only can make it fuller, angle remains) so never work properly off-wind.
To change the angle of incidence to the wind boom is necessary. Unless the boat is reeeeely wide, as cats.
Sailed with boomless main though, but this had gaff

To Whit

We have snatch blocks and seco ndary sheets to set the genoa off the toe rail... Indeed I almost never use just the Genoa track..

You could use a very wide traveller on an arch.. but you would loose the advantage of the kicking strap to control twist on the leech..

 

[Tomahawk]

Sheeting angle. Without the boom you only get sail at angle from tack to sheet block. Fixed. Like on a jib, always set for close-hauled (this gets sometimes forgotten - but you only can make it fuller, angle remains) so never work properly off-wind.
To change the angle of incidence to the wind boom is necessary. Unless the boat is reeeeely wide, as cats.
Sailed with boomless main though, but this had gaff

To Whit

We have snatch blocks and seco ndary sheets to set the genoa off the toe rail... Indeed I almost never use just the Genoa track..

You could use a very wide traveller on an arch.. but you would loose the advantage of the kicking strap to control twist on the leech..

 

[25931]

With these modern dart shaped on deck yachts, is there any need for a boom at all especially if furling main is a feature.Seems one could simply do without the boom mostly and outhaul from the quarter if off the wind?
The Legend USA yachts used to feature a sturdy arch for sheeting the main, does this not obviate the need for a main boom?
What do the forum think?

How could you goose-wing ?

 

[DJE]

Why not a boom on the jib?

 

[blackbeard]

Why not a boom on the jib?

This used to be the norm, at one time, for the staysail with a cutter or ketch rig ... but:
a. you cannot control sail shape, as already noted, so if it's right for going to windward it won't be optimised for going downwind
b. going downwind it may be inclined to slam from side to side, when
c. it makes the foredeck a dangerous place

On the other hand ... self tacking jibs are becoming popular ... there's a track for the block, but no jib boom ... when going to windward the tension in the sheet is greater than for going downwind, so sail will be flatter ... they still work when sail is roller-reefed ...

with a fairly wide transom and suitably long track, can't see why this shouldn't work for the mainsail - you would need some additional string to prevent the block coming across in an unintentional "gybe" , but this should be easy enough to arrange ...
luggers sometimes had a bumpkin (sticking out aft of the transom) with the clew of the main sail sheeted to this; with a track for the mainsail block you wouldn't need the bumpkin

 

[jwilson]

If you had a Legend/Ovni style arch you COULD set a main without a boom, if it was cut for it, but you would find it grossly inefficient offwind, and when you gybed you'd either have a loop of sheet or worse a heavy block whipping around above the cockpit. If you ever break a boom and have to set the main without one you will find out the disadvantages ...

 

[Mrnotming]

Some kites have inflating sections now to aid the shape keeping.
Maybe an inflating lower section would make the boomless main useable offwind, of course that would lead to it being used upwind too!
Oh! can't sail today I've got a leaky boom!

 

[JimC]

... On the other hand ... self tacking jibs are becoming popular ... there's a track for the block, but no jib boom ... when going to windward the tension in the sheet is greater than for going downwind, so sail will be flatter ... they still work when sail is roller-reefed ...

I've had two boats with self-tacking jibs. In my experience they are fine when on the wind but as you come off the wind and ease the sheet the upper leech sags away to leeward so you tend to over-sheet the lower part of the sail to keep the upper part drawing properly. I believe it's caused by the pull on the sheet being almost vertically downward onto the traveller so when the sheet is eased the clew lifts and the sail twists excessively. Some people rig Barber haulers to move the sheeting point outwards and/or rearwards, but by the time you've done that you could have sheeted in a conventional jib. Like anything else S/T jibs have their pros and cons.

 

[Daydream believer]

I've had two boats with self-tacking jibs. In my experience they are fine when on the wind but as you come off the wind and ease the sheet the upper leech sags away to leeward so you tend to over-sheet the lower part of the sail to keep the upper part drawing properly. I believe it's caused by the pull on the sheet being almost vertically downward onto the traveller so when the sheet is eased the clew lifts and the sail twists excessively. Some people rig Barber haulers to move the sheeting point outwards and/or rearwards, but by the time you've done that you could have sheeted in a conventional jib. Like anything else S/T jibs have their pros and cons.

I have a self tacking jib & would not go back to a conventional jib.
It is so much easier.
The main is larger so the downwind is not such a problem . Plus i do rig a barber hauler & because i am not tacking once it is set it stays set for quite a while . If wind is light then the cruising chute goes up
If i want to suddenly do some tacks i just free the hauler for a while. The set up is miles easier than with a normal jib
But i admit 90% of my sailing is single handed
If i am racing & have a crew then i rig the genoa if the course has a lot of off wind legs. But only of i need the extra power in light winds
The s tacker helps me point higher as well
In a blow i do not have to reef it even in F8. I just reef the main from the cockpit
So the jib keeps its optimum shape for performance