When to use running checkstays?

[Fergus]

Monohull masthead rig with removable cutter stay. If the cutter stay is not rigged do I need to use them? If so on all points of sailing once wind is F6 or higher/heavy seas etc?

Answers on a postcard please!

 

[lw395]

It depends! All rigs seem to be different.
Probably with a cutter stay, they are primarily to stop that bending the mast excessively, but they can also be used to control mast bend for mainsail fullness/shape, and to avoid the rig 'panting' or cyclically bending in waves.
Depending on your spreaders etc (inline or swept?) using the checks without the cutter/babystay may invert the mast, generally held to be a bad idea.
Hope that helps?

 

[Fergus]

spreaders are inline - since I don't plan on using the cutterstay often I guess I'll just use them when it's windy and/or rough and particularly on sailing points where aft strain is greatest - reaching/running?

 

[TigaWave]

The checkstay is the one below the Runners or running backstay, and restricts the forward movement of that part of the mast. In a bendy mast set up you can pull this part of the mast back to help straighten it and give a fuller main. Straight mast, ease backstay pull on check stay.



In your set up I assume it will be there to keep the mast straight and balance the loads of the baby stay.

There were some links posted to other rig set up sites, but I can't find them right now. This advice is from UK sails.
http://www.alohaowners.com/pages/projects/rig/mastheadrig.htm

 

[tome]

Do you mean running checkstays or running backstays?

Are the stays attached to the mast in line with the inner (cutter) forestay?

 

[Fergus]

I guess they're backstays then - in line with where the cutterstay joins the mast

 

[tome]

Ok, then you will only need them at all when using the inner stay. The backstay tensions the forestay on a masthead rig

The reason they are fitted is to stop the mast bending when using the inner stay. If the inner stay is close enough to the outer (within a foot or so) you don't need runners at all, but I guess yours is well below this

 

[William_H]

tome is right. It all depends. If the mast is really large in fore and aft dimension tyhen it has a fair bit of stiffness in itself. If it is not ie round mast then it will need more help in the fore and aft direction.
A true curtter type rig will have the innner cutter stay about 2/3 of the way up the mast. We might expect then to have spreaders and side stays at this point. We would also expect to see spreaders and side stays about half way from the cutter stay to the deck.
If your "cutter stay" is closer to the deck it might just have spreaders and side stays at half height point. (assuming mast head forestay)
The mast will need fore and aft stability near the middle unless it is very stiff. This is acheived by a baby forestay or aft swept spreaders to get the pull forward and sidestays chainplate aft of abeam the mast. So sidestays also pull back.

A plan of what you have in thge way of stays woiuld help a lot. However I would suggest that you probably need the running backstays to load up the cutter forestay when it carries a sail and to locate that part of the mast fore and aft if the cutter forestay is tensioned even without a sail.
An alternative to the running backstays is a pair of sidestays which go to chain plates aft of abeam the mast. This method doesn't have the power of the running backstays to pull in the aft direction (The power aft depends on the distance aft of the mast simple geometry) howeveer it has the advantage that they can remain attached and be tensioned quite tight. The disadvantage is that the mainsial will chafe on the stays when running square. (Many boats including mine and most fractional rigs put up with this inconvenience.)

So if you remove the cutter stay then suggest removable or at least tied back running backstays. If the cutter stay is permanent then you should fit aft swept sidestays. (Typically about 15% of boom lenght aft of abeam the mast.) You can then have optional running backstays.
It is all a matter of degrees so you perhaps should consult a rigging designer or specialist. You need a strong rig oif you are going to ahve peace of mind in a blow. olewill

Just rereading your question disregard above waffle. Presumably your cutter forestay is for an alternative jib to the roller blind up front. The cutter forestay if it is mounted near the main forestay or more particularly the backstay will not need much extra support. if however it is lower it will need the running backstays.
You don't need to set up the running backstays with the cutter forestay not fitted as the load on the running backstays will not be counterbalanced by a forestay load. We are presuming that the rig is well stayed by design without the cutter forestay or the running backstays good luck olewill

 

[Fergus]

Thanks for all the advice - it seems pretty clear that I only need to use them when the cutterstay is in use. This is the swenglish reply I got from Sweden yachts which prompted the question!

It has to be used,
When cutterstay is connected,
rough sea,
rough sea and high windforce,
and somtime for trimming purpose if wanted,

 

[Robin]

Fergus, for added confirmation we have a similar setup with a removeable cutter stay about 2/3rds up the mast and running backstays to balance this when it is in use to carry either a staysail or the storm jib. Normally the cutter stay is stowed back near the mast and the running backstays stowed at the forward ends of the genoa tracks. In all normal sailing in our case the runners and cutterstay are not used, they are an extra to the standard rig for extreme conditions.

Robin