Another spinnaker crane question

[Plevier]

Prompted by aitchem's question and not wishing to hijack his thread.
I have a slightly fractional - about 95% - Sparcraft rig. The spinnaker halyard emerges through a sheave box in the mast combined with the genoa halyard sheave box and the forestay attachment. The pic below was taken before the spin halyard was installed but it exits just above the forestay.
It's a horrible arrangement with lots of side friction and forestay fouling.
Any solution? Is it OK to put a crane on the masthead or must the spin hal be in line with the capstays? Is there another way?
(Before anyone suggests it, I have fitted a gen hal guide on the mast and could now remove the deflector disk.)

Later - looking at the Selden yacht catalogue page 150 there is a photo showing a similar fractional rig with the spin hal going to a masthead crane so must be OK?

 

[William_H]

Yes it would probably be quite OK to fit a small crane and sheave to the top of the mast. There can be a lot of sideways pull on a spin top but your cap shrouds being so close to the top should be OK. Certainly the further away from the forestay the better.
However you will always get friction with a fixed in mast sheave because the spin is seldom straight out in front. The sheave box needs to be able to cope with off centre pull or do as I did and fit a dead eye guide just below the sheave to manage side load and guide the halyard straight onto sheave. Or just have a pulley on a swivel.
Many large (3/4) fractional rig racers will carry spins for strong winds halyard just above the forestay and another halyard at mast head for a really big light weather mast head spin. For my experience it is always the boat stability rather than rig strength that limits spin size in strong winds. Yes poor little boat forgets the golden rule " keel down mast up".
good luck olewill

 

[Bosun Higgs]

It looks to me as if your rig is a high fraction eg 15/16 not 3/4, so there isnt a lot of mast above the forestay and shroud attachment points. Personally I would risk attaching to the masthead but if you wanted you could put another sheave box between the genoa one and the masthead itself.

The biggest problem I found with spinny near the foil was of spinny halyard wraps when using the roller reefing. Avoiding that seems to require the spinny halyard when taut to be more than 4 inches away from the foil and furled sail.

Ask the guys at allspars or z spars for advice. both are very helpful.