Single or twin groove forestay?

rosie

Well-Known Member
Joined
2 Feb 2002
Messages
132
Location
Me East Anglia, boat Normandy
Visit site
I am thinking of changing my old Colnebrook roller reefing (up & down halyard) for Plastimo 810. This comes with single or twin groove. The twin groove takes a 5mm luff rope so I could use my existing genny without modification, whereas the single takes a 6.5mm luff rope. Besides this and the ability to carry twin headsails are there any other advantages/disadvantages with twin compared with single groove? Your views would be appreciated.
 
I would go for twin ... but if economy is needed - the single wins hands down ...

The sail can be altered easily .... the luff core can be removed and larger inserted ... rare if it cant. You could do it yourself if you wanted to ... Most sailmakers use a fibrofil core .... looks like washing line stuff .... The interesting thing is that the core does not have to be that strong to carry the halyard tension - the sail does that !

I repaired a genny years ago by inserting lengths of fibrofil cord in the damaged sections - after a sailmaker gave a daft quote. Worked fine .... I even sold the whole system and sail onto another guy ... I told him what I had done ... as far as I know 8 yrs later he is still using the same sail.

The thing about many items sail wise etc. - Lay out the sail on the lawn etc. - look at it closely and you will find things you can do without too much bother ... I don't advocate we can do without sailmakers - far from it - they are a skill that is to be admired ... but there are many small jobs we can do ...

Fitting slugs ...
Re-coring luff
limited re-stitching
etc.
 
No question, if you have the facility for installing twin groove then go for it. The experience of peeling genoas without change in course or speed is a rare delight - and keeps the crew busy too!
 
I had a Plastimo system, on a previous boat which had a threaded travellor which the top of the sail attached to via a cranked shackle. The bottom bit of the travellor undid itself 3 times whilst sailing for no apparant reason- finally solved with superglue...
I currently have a Colnbrook system which has never given me any problems, except that I have to "rig" a halyard when I want to remove or change sails. It also gives me another halyard on the top of the mast as a second spinnacre/genoa halyard.

I dont know if the Plastimo is the same now, as it was then, but if it is, I would suggest dont fix whot aint broke.

Twin groove foils are obviously a benefit if you want to change sails on the fly or gull wing two sails, but even the old Colnbrook system allows this...
My stemhead system failed on the last boat, and having got two back stays and half a dozen shrouds, I could not understand why there is only one forestay. I have fitted a second forestay outside the foil, so that there is a second wire to attach sails to... granted that the method of attachment is different. I have a storm jib with pistons hanks, and a old genoa wirh plastic hanks, which allows gull winging, leaving the main genoa for normal sailing. If the stemhead fitting fails, then there is a second forestay holding up the mast. In days of old the foresail would have been raised with a plough halyard, which in the event of a failure would have held the mast up.
 
Basically it's about cruising or racing.
If you're mainly cruising you don't need twin foil grooves.
Set a lightweight genoa flying.
For belt and braces arrange a removable inner foresaty so you can slutter.
 
When I was faced with that decision it was a no-brainer for me. (a) no possibility of ever wanting to hoist 2 headsails (I only have one!), (b) the bigger the groove the less likely the bolt rope is to pull out (Ithink). Ergo - single groove.
 
There's also been a couple of suggestions of sail peeling with twin grooves. Unless I'm missing something, that ain't gonna happen with a furling system although I crew on a yacht fitted with a furler and, when racing, the drum gets removed.
 
Top