ghostlymoron
Well-known member
I'm told that a loose footed mainsail gives better performance. Why do most run in a track?
Mainsail loose or fixed footed
- Thread starter ghostlymoron
- Start date
sailorman
Well-known member
mine is in the track but totally adjustable under sail, we have a leach Cunningham,to flatten the foot as apparent wind increases
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xyachtdave
Well-known member
You need to hold the clew of the sail on to the boom somehow. A bolt rope along the boom (foot of the sail) is not as adjustable as one where only the clew is attached by either a car/slug in the boom track or a Velcro strap around the boom itself.
It doesn't really matter how the clew is attached to the boom, ideally you don't want the sail foot in the track also.
'Big ease' when running etc!
It doesn't really matter how the clew is attached to the boom, ideally you don't want the sail foot in the track also.
'Big ease' when running etc!
Quandary
Well-known member
It saves a bolt rope and a panel of cloth and does not seem to reduce performance so you can understand why sailmakers will tell you it is faster. Possibly without the drag of the rope in the boom groove the outhaul is more responsive so perhaps it may be marginally easier to adjust. Most mainsails are loose footed these days but you will still have a full length track in the top of the boom for the forseeable future.
Ex-SolentBoy
New member
One of the many reasons I prefer an inmast main!
JimC
Well-known member
With a loose-footed mainsail the bottom of the sail is able to form an aerodynamic curve rather than being forced into a straight line from luff to leach by the boom. The contour of the curve can be optimised for the conditions by adjusting the clew outhaul. To achieve something like the same effect with a non loose-footed sail the bottom panel can be cut very full such that the sail can fill into a curve not far above the boom and this fullness can be pulled out when required with a flattening reef or cunningham as described by Sailorman. My own boat has this system but the owner of an identical boat has recently changed his mainsail to loose-footed and claims very worthwhile increases in performance and general 'tuneabilty'. As regards why do most sails run in a track I guess convention has a lot to do with it, also It's probably stronger and safer: a failure of the clew slider won't release the sail out of control or drop the boom onto the crew if the topping lift happens to be slack.
Quandary
Well-known member
Proper mainsails with real battens and a roach are almost all loose footed these days.
Dipper
Well-known member
When you (slab) reef the main it becomes loose footed.
rivonia
Active member
Hmm, I think that I disagree ! I look inthe marina and ALL are in the boom. Those without mainsails (for the winter) say they run in the groove.
Where did you get your info from?
Peter
Quandary
Well-known member
Sorry, No argument with your observation, I was referring to new sails, just ask a sailmaker.
rivonia
Active member
Skysail
Well-known member
Try finding a performance dinghy without a loose footed main. They don't do it to save money.
AndrewB
Well-known member
When I first tried dinghies with loose footed mainsails in the 70's, Laser in particular, I thought that the sail quickly stretched moving the centre of effort backwards and making it less controllable in strong wind as well as less close-winded. The same seemed even more true of the early in-mast reefing yachts.
These were Dacron sails. I guess with modern sail materials that isn't a problem.
These were Dacron sails. I guess with modern sail materials that isn't a problem.
Robin
Well-known member
Loose footed is better and isn't just a cheap option. It allows for easier adjustment as there is less friction and you still can have a flattener reef and luff cunningham for tweakability. The clew is usually on a slug that runs in the boom groove, sometimes with an added Dyneema strap velcroed around the boom for very high load sails on raceboats. As someone else has said, slab reefs are always loose footed, unless you are daft enough to tie in fixed reef points which are for tidying only and really unnecessary. If you have a stakpak sail cover it no longer competes with a foot rope for space in the boom groove so how it is attached will need to be reviewed as it may need a bolt rope of it's own to stay in place.
Most new sails are loose footed. If you see lots of sails that are not then they are old sails, seemples!
In mast reefing, sail shape and performance do not go together, they are merely roll out cloths for adornment when motor sailing.
Most new sails are loose footed. If you see lots of sails that are not then they are old sails, seemples!
In mast reefing, sail shape and performance do not go together, they are merely roll out cloths for adornment when motor sailing.
prv
Well-known member
Interesting to see the apparent consensus that loose-footed sails are more efficient. That being the case, anyone know why sails were fixed along the boom at all? Loose footed isn't a new idea, my Gaff Rig book is full of pictures of hundred-year-old boats with loose-footed sails.
Pete
Pete
ghostlymoron
Well-known member
Loose footed is better and isn't just a cheap option. It allows for easier adjustment as there is less friction and you still can have a flattener reef and luff cunningham for tweakability. The clew is usually on a slug that runs in the boom groove, sometimes with an added Dyneema strap velcroed around the boom for very high load sails on raceboats. As someone else has said, slab reefs are always loose footed, unless you are daft enough to tie in fixed reef points which are for tidying only and really unnecessary. If you have a stakpak sail cover it no longer competes with a foot rope for space in the boom groove so how it is attached will need to be reviewed as it may need a bolt rope of it's own to stay in place.
Most new sails are loose footed. If you see lots of sails that are not then they are old sails, seemples!
In mast reefing, sail shape and performance do not go together, they are merely roll out cloths for adornment when motor sailing.
Robin, you're asking for trouble! Many boaters (not sailors) are very proud of their in mast arrangements. I've not seen many racing yatchs with them though and the main trouble with such systems is that they can jam - either in or out.
Quandary
Well-known member
The soft stretchy panel with a bolt rope closing the aperture to the boom was thought to be more efficient in forming an 'endplate' to the flow over the widest part of the sail and persuading the air to flow aft rather than spill downwards. It was really tricky to cut and make as it had to perform in various positions as the draft* was adjusted without distorting the flow across the foot. If your sailing theory books were as old as some of mine you would read the explanation for the introduction of this innovation, what is amazing is that with all the research done on the subject over the years it took so long to go out of fashion.
draft* = American spelling universally used by switched on sailmakers.
Robin
Well-known member
I don't know why it has taken so long. Surely I can't get into trouble for telling it like it is!
westernman
Well-known member
I think I have seen sails with zippers low down to change the draft there.
Bosun Higgs
N/A
Most sailors arent interested in performance or they wouldnt sail the boats they do.