underdog
Well-Known Member
What are the relative advantages and disadvantages of either configuration? Which is preferred by the members of this forum?
Fractional or Masthead rig
- Thread starter underdog
- Start date
dunedin
Well-Known Member
What for - racing or cruising; inshore or blue water; speed or ease of use.
It depends !
Clyde_Wanderer
Well-Known Member
I am led to believe Fractional is more common on racing yachts or racer/cruisers.
Probably better with a Masthead for an all cruiser.
C_W
Probably better with a Masthead for an all cruiser.
C_W
photodog
Lord High Commander of Upper Broughton and Gunthor
Fractional is more tuneable.... so more bits of string to play with and a better ability to go a bit faster and get the boat optimised for the conditions...
But there are fractional rigs.. and then there are REALLY fractional rigs... so something like my Bavaria is like 9/10ths..... so its not in need of a lot of continuous fidling....
I think that most modernish cruisers benefit from a fractional rig... certainly if you are big on the sailing then a modest fractional rig can be a good thing.
Masthead rigs tend to be thought of as much stronger... so if you are inclined to rufty tufty southern ocean then maybe its a better bet.... But I like the ability to flatten the main easily with my rig...
But there are fractional rigs.. and then there are REALLY fractional rigs... so something like my Bavaria is like 9/10ths..... so its not in need of a lot of continuous fidling....
I think that most modernish cruisers benefit from a fractional rig... certainly if you are big on the sailing then a modest fractional rig can be a good thing.
Masthead rigs tend to be thought of as much stronger... so if you are inclined to rufty tufty southern ocean then maybe its a better bet.... But I like the ability to flatten the main easily with my rig...
snowleopard
Well-Known Member
Fraction rigs generally need extra rigging to support the forestay in the form of runners, jumper struts or extra aft shrouds. These can be inconvenient or even dangerous at times. However but they tend to perform better and be closer-winded. A smaller foresail can be a benefit when short-handed. A masthead rig is more bullet-proof as regards staying but a big genoa needs big winches and can be a handful for a small crew.
For offshore cruising my preference would be for a masthead cutter with self-tacking staysail. The staysail can be left up in really heavy weather while the yankee is furled. With a sloop your foresail becomes less efficient when deeply reefed so you may need to get up on the foredeck to rig a storm jib if you need to make to windward.
An alternative for short-handed sailing or e.g. a couple with a lightly-built woman is a ketch as it means all the sails are smaller and dropping the main gives you an instant easily-handled rig. The drawback is that few mizzens set well on a beat so it's like having an under-powered sloop. Having done one transatlantic with ketch rig I wouldn't have one myself but some people like them.
For offshore cruising my preference would be for a masthead cutter with self-tacking staysail. The staysail can be left up in really heavy weather while the yankee is furled. With a sloop your foresail becomes less efficient when deeply reefed so you may need to get up on the foredeck to rig a storm jib if you need to make to windward.
An alternative for short-handed sailing or e.g. a couple with a lightly-built woman is a ketch as it means all the sails are smaller and dropping the main gives you an instant easily-handled rig. The drawback is that few mizzens set well on a beat so it's like having an under-powered sloop. Having done one transatlantic with ketch rig I wouldn't have one myself but some people like them.
LouisBrowne
Well-Known Member
Adding a bit of detail to the previous comments;
Masthead rig
Advantages:
The mast is supported all the way up and down so it is bullet-proof.
The spreaders are in line with the mast laterally so, when you are running, the boom can go out all the way and project maximum sail area.
You can use full-size masthead spinnakers.
Disadvantages:
Masthead yachts often have large genoas that are tiring to tack.
You cannot easily bend the mast to flatten the mainsail while sailing and so it is harder to de-power.
Fractional rig
There are various kinds.
Fractional with in-line spreaders (spreaders in line with mast laterally) were common on IOR racing yachts in the 80s and 90s. The mast has no fore and aft support at the point where the forestay is attached and so it needs running backstays for support. This type of rig is complicated and delicate and is not suitable for a cruising yacht.
Fractional with swept-back spreaders: the spreaders are angled aft and the shroud bases are aft of the foot of the mast so the shrouds provide fore and aft support as well as lateral support. This is the type of rig used on the Westerly Fulmar and Sigma 33 etc
Advantages:
As the wind increases you can de-power very easily and effectively by simply pulling down the backstay (which will have a powerful tackle). This bends the mast on a fractional rig and flattens the mainsail.
The smaller foretriangle means smaller headsails, making tacking easier.
Large mainsail / smaller headsail is also good in that a reefed main sets well whereas a deeply roller-reefed headsail does not.
Disadvantages:
The swept-aft spreaders mean that you cannot let the main right out when running and can cause chafe.
The mast is not supported laterally above the point where the forestay attaches to it so fractional rigged cruisers often have all purpose fractional spinnakers which means loss of downwind sail area compared with a masthead spi.
A fractional rig with swept-back spreaders is quite safe and efficient.
Another type of fractional rig, which is used on some American boats imported to England (Hunter Legend I think), has radically swept back spreaders and no backstay, like a dinghy.
The advantage is that you can have a mainsail with a big roach. The disadvantages are that letting out the mainsail when going downwind is even more restricted and it is hard to de-power because there is no backstay. Perhaps you use the kicking strap to bend the mast, as on a dinghy, but I would have thought that this would put unfair strain on the boom mast and gooseneck.
Masthead rig
Advantages:
The mast is supported all the way up and down so it is bullet-proof.
The spreaders are in line with the mast laterally so, when you are running, the boom can go out all the way and project maximum sail area.
You can use full-size masthead spinnakers.
Disadvantages:
Masthead yachts often have large genoas that are tiring to tack.
You cannot easily bend the mast to flatten the mainsail while sailing and so it is harder to de-power.
Fractional rig
There are various kinds.
Fractional with in-line spreaders (spreaders in line with mast laterally) were common on IOR racing yachts in the 80s and 90s. The mast has no fore and aft support at the point where the forestay is attached and so it needs running backstays for support. This type of rig is complicated and delicate and is not suitable for a cruising yacht.
Fractional with swept-back spreaders: the spreaders are angled aft and the shroud bases are aft of the foot of the mast so the shrouds provide fore and aft support as well as lateral support. This is the type of rig used on the Westerly Fulmar and Sigma 33 etc
Advantages:
As the wind increases you can de-power very easily and effectively by simply pulling down the backstay (which will have a powerful tackle). This bends the mast on a fractional rig and flattens the mainsail.
The smaller foretriangle means smaller headsails, making tacking easier.
Large mainsail / smaller headsail is also good in that a reefed main sets well whereas a deeply roller-reefed headsail does not.
Disadvantages:
The swept-aft spreaders mean that you cannot let the main right out when running and can cause chafe.
The mast is not supported laterally above the point where the forestay attaches to it so fractional rigged cruisers often have all purpose fractional spinnakers which means loss of downwind sail area compared with a masthead spi.
A fractional rig with swept-back spreaders is quite safe and efficient.
Another type of fractional rig, which is used on some American boats imported to England (Hunter Legend I think), has radically swept back spreaders and no backstay, like a dinghy.
The advantage is that you can have a mainsail with a big roach. The disadvantages are that letting out the mainsail when going downwind is even more restricted and it is hard to de-power because there is no backstay. Perhaps you use the kicking strap to bend the mast, as on a dinghy, but I would have thought that this would put unfair strain on the boom mast and gooseneck.
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doug748
Well-Known Member
I had a small very slippy Folkboat type with fractional rig and swept back spreaders and I loved it. The chafe thing can be a worry with the particularly large main. If you let go the backstay in a blow you can turn the rig 'inside out' and invert the spreaders but this will not be a problem given normal levels of care. It will put an S bend in a mast and could bring it down though.
Flaming may be along to add his forensic comment on the racing scene. He is not a fan of mashead rig and I normally see his point, but:
I have a mashead rig now and can see certain advantages. If you are short handed, and not racing, there is less to fiddle with and get wrong. It is very stout so that mast should always stay in column and please the offshore sailor. I always liked the small headsails of the fractional rig but with roller reefing the bigger headsails are now managable (if not so efficient) a particular plus for the singlehander.
My present main seems to have three reefs: up (at sea) , down (in harbour) and hove to in the Southern Ocean.
PS
Nearly forgot, the biggest pain is tacking the large genoa. This destroys the sail and is not a pleasure. The fractional blade tacks like a dinghy, another racing plus.
I always put half of the foresail away when doing short tacks.
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snowleopard
Well-Known Member
A slight divergence here. My rig is unstayed so mast support issues are eliminated but the rig is fractional. The small self-tacking blade jib is easy to set & furl - I only need to use the little 6-power cotton-reel winch to furl if it's really blowing. Furling the jib is the first reef. Despite that, setting the jib in lighter winds adds tremendously to power and speed.
It's no coincidence that racing dinghies all have fractional or una rigs.
It's no coincidence that racing dinghies all have fractional or una rigs.
