This is the mast on my mate's newly acquired Farr 37. It had this prebend ever since it arrived here about 3 years ago. The luff round in the mainsail is a long way off! I have tried to alter the bend previously and spent some time yesterday trying to adjust it. I think having the luff round cut to suit may be the only answer. The halyard is tight along the mast and I estimate the gap in the centre to be 120mm. Easing the backstay has no effect.

You may have to ease the cap shrouds as there may not be enough length in them to allow the mast to come back in column.

I had similar problem with my Adams 10 ,easing the caps was the answer , well picked.

It is a Farr 37, has check stays, designed to be used all of the time i thin k you will find.
L

Like a J35 or Sydney 41, checks control compression which controls rig tension and forestry sag.

A quick search shows the Glass Yachts built boat had permanent checks and the later Robertson build boats must have had a different section or sleeve and no checks

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lydia said..
Like a J35 or Sydney 41, checks control compression which controls rig tension and forestry sag.

A quick search shows the Glass Yachts built boat had permanent checks and the later Robertson build boats must have had a different section or sleeve and no checks

This is Robertson's own boat as far as I can determine. The interior is of an extremely high standard. There are rope check stays but I would say they have not been used. I eased off the cap shrouds and that had no effect other than to make the upper and intermediate diagonals loose.

Good article here. afloat.ie/resources/marine-industry-news/uk-sailmakers-ireland/item/38282-tuning-a-fractional-mast

Lower down the bit about prebend for J109's has their prebend at 130mm. Pretty close to what we have. The cap tension is a lot higher than I am used to. The article mentions tightening the intermediates more to straighten. This is a masthead rig and that seems a lot of prebend.
I have suggested getting the local sailmaker to have a look. The photo is from a couple of years ago as I passed her. The lack of luff round in the main is obvious.

check the mast base as compared to the deck chocks.
Looks to all low down so check how far the mast is chocked formed at deck level.

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lydia said..
check the mast base as compared to the deck chocks.
Looks to all low down so check how far the mast is chocked formed at deck level.

The mast is deck stepped. The top photo shows the mainsail halyard pulled tight and attached hard up to the sail track at the gooseneck.
At sea in 15 knots, the mainsail looks a lot worst when looking up the mast.

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Ramona said..

lydia said..
check the mast base as compared to the deck chocks.
Looks to all low down so check how far the mast is chocked formed at deck level.

The mast is deck stepped. The top photo shows the mainsail halyard pulled tight and attached hard up to the sail track at the gooseneck.
At sea in 15 knots, the mainsail looks a lot worst when looking up the mast.

Is that sail been made to fit that boat? The creases running up from the foot look mighty tight,

Note the bend on this Farr 37. Piccy from DBY boat sales of 1992 Robertson Farr 37 (www.dbyboatsales.com.au/listing/farr-37/). Some chance it is the same boat (this one went by the name Electra 2 and was sold, perhaps in 2019), but if not the same boat, suggests mast bend is a feature.

If I had to guess that sail nos does not match the age of the boat being NSW.
Not the right mainsail.

Battens are too short for that vintage as well and no full length top batten.

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Quixotic said..
Note the bend on this Farr 37. Piccy from DBY boat sales of 1992 Robertson Farr 37 (www.dbyboatsales.com.au/listing/farr-37/). Some chance it is the same boat (this one went by the name Electra 2 and was sold, perhaps in 2019), but if not the same boat, suggests mast bend is a feature.

Same boat.

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lydia said..
If I had to guess that sail nos does not match the age of the boat being NSW.
Not the right mainsail.

Battens are too short for that vintage as well and no full length top batten.

The sail is in as new condition and I believe the numbers on the spinnakers match.

Looks like babystay and checkstays, so if you want the straighten the mast, ease the babystay and crank on the checkstays. Screwing around with shroud tension isn't going to do much to alter the bend as it's almost an in-line spreader rig.

That being said, It's more that the luff curve of the main is just cut wrong. Thats a fairly normal looking amount of bend.

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cambid said..
Looks like babystay and checkstays, so if you want the straighten the mast, ease the babystay and crank on the checkstays. Screwing around with shroud tension isn't going to do much to alter the bend as it's almost an in-line spreader rig.

That being said, It's more that the luff curve of the main is just cut wrong. Thats a fairly normal looking amount of bend.

The baby stay is slack and the checkstays have no effect on the bend. They are there for spinnaker work in fresh breezes I would think. I think the sailmaker will need to assess and decide on the luff round required in the mainsail.

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Ramona said..

Quixotic said..
Note the bend on this Farr 37. Piccy from DBY boat sales of 1992 Robertson Farr 37 (www.dbyboatsales.com.au/listing/farr-37/). Some chance it is the same boat (this one went by the name Electra 2 and was sold, perhaps in 2019), but if not the same boat, suggests mast bend is a feature.

Same boat.

Fair enough. I don't understand why there are check stays on a masthead rig. Makes sense on a fractional rig where the lower forestay can pull the mast forward below the back stay, but that's not the case on a masthead rig. Leaving that to one side, pure geometry says to unbend the mast in question requires the rig to be slackened at the back stay and at the shrouds, because an unbent mast will be taller. I suspect the forestay should also be slackened a bit or the top of the mast as it unbends will move the whole angle of the mast forward. So if it were mine I would assume the rig needs to be retuned from scratch, starting by slackening everything off. And I'd likely get a professional rigger who knows Farr 37s to do it.

This my last boat Farr 37.Pippin..it looks the mast has identical bent .Pippin was professionally tuned, before Sydney Hobart race, as she was winner in her category. Later fully set up for Osaka race, never went. Many years neglect etc.

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Charriot said..


This my last boat Farr 37.Pippin..it looks the mast has identical bent .Pippin was professionally tuned, before Sydney Hobart race, as she was winner in her category. Later fully set up for Osaka race, never went. Many years neglect etc.

Thanks for that. That mast looks identical. Electra 2 was professionally rigged and tuned. Most of us mere mortals would not dare to use the rig tension this boat has on the cap shrouds.
After an on the water conference today it seems the sail numbers don't match those on the spinnaker so we have to presume the main sail is off another boat. A sail recut is on the cards and the sailmaker can sort out the luff round. Now that we know Pippin has the same mast with the same bend we can search out photos.

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Quixotic said..

Ramona said..

Quixotic said..
Note the bend on this Farr 37. Piccy from DBY boat sales of 1992 Robertson Farr 37 (www.dbyboatsales.com.au/listing/farr-37/). Some chance it is the same boat (this one went by the name Electra 2 and was sold, perhaps in 2019), but if not the same boat, suggests mast bend is a feature.

Same boat.

Fair enough. I don't understand why there are check stays on a masthead rig. Makes sense on a fractional rig where the lower forestay can pull the mast forward below the back stay, but that's not the case on a masthead rig. Leaving that to one side, pure geometry says to unbend the mast in question requires the rig to be slackened at the back stay and at the shrouds, because an unbent mast will be taller. I suspect the forestay should also be slackened a bit or the top of the mast as it unbends will move the whole angle of the mast forward. So if it were mine I would assume the rig needs to be retuned from scratch, starting by slackening everything off. And I'd likely get a professional rigger who knows Farr 37s to do it.

Slackening the backstay makes no difference. With the backstay and forestay tight it's very strange to be able to grab the check stay or baby stay and jiggle the mast and watch the whole lot wobble like a dinghy mast.

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Ramona said..

Charriot said..


This my last boat Farr 37.Pippin..it looks the mast has identical bent .Pippin was professionally tuned, before Sydney Hobart race, as she was winner in her category. Later fully set up for Osaka race, never went. Many years neglect etc.

Thanks for that. That mast looks identical. Electra 2 was professionally rigged and tuned. Most of us mere mortals would not dare to use the rig tension this boat has on the cap shrouds.
After an on the water conference today it seems the sail numbers don't match those on the spinnaker so we have to presume the main sail is off another boat. A sail recut is on the cards and the sailmaker can sort out the luff round. Now that we know Pippin has the same mast with the same bend we can search out photos.

Nice picture, newer seen it.Lovely to sail, wonder where is now. Sold it 3 years ago.

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Quixotic said..

Ramona said..

Quixotic said..
Note the bend on this Farr 37. Piccy from DBY boat sales of 1992 Robertson Farr 37 (www.dbyboatsales.com.au/listing/farr-37/). Some chance it is the same boat (this one went by the name Electra 2 and was sold, perhaps in 2019), but if not the same boat, suggests mast bend is a feature.

Same boat.

Fair enough. I don't understand why there are check stays on a masthead rig. Makes sense on a fractional rig where the lower forestay can pull the mast forward below the back stay, but that's not the case on a masthead rig. Leaving that to one side, pure geometry says to unbend the mast in question requires the rig to be slackened at the back stay and at the shrouds, because an unbent mast will be taller. I suspect the forestay should also be slackened a bit or the top of the mast as it unbends will move the whole angle of the mast forward. So if it were mine I would assume the rig needs to be retuned from scratch, starting by slackening everything off. And I'd likely get a professional rigger who knows Farr 37s to do it.

Check are for rig tension control as compression softens the rig tension.

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Quixotic said..

Ramona said..

Quixotic said..
Note the bend on this Farr 37. Piccy from DBY boat sales of 1992 Robertson Farr 37 (www.dbyboatsales.com.au/listing/farr-37/). Some chance it is the same boat (this one went by the name Electra 2 and was sold, perhaps in 2019), but if not the same boat, suggests mast bend is a feature.

Same boat.

Fair enough. I don't understand why there are check stays on a masthead rig. Makes sense on a fractional rig where the lower forestay can pull the mast forward below the back stay, but that's not the case on a masthead rig. Leaving that to one side, pure geometry says to unbend the mast in question requires the rig to be slackened at the back stay and at the shrouds, because an unbent mast will be taller. I suspect the forestay should also be slackened a bit or the top of the mast as it unbends will move the whole angle of the mast forward. So if it were mine I would assume the rig needs to be retuned from scratch, starting by slackening everything off. And I'd likely get a professional rigger who knows Farr 37s to do it.

Check are for rig tension control as compression softens the rig tension.

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lydia said..
If I had to guess that sail nos does not match the age of the boat being NSW.
Not the right mainsail.

Battens are too short for that vintage as well and no full length top batten.

Bump

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Ramona said..

Charriot said..


This my last boat Farr 37.Pippin..it looks the mast has identical bent .Pippin was professionally tuned, before Sydney Hobart race, as she was winner in her category. Later fully set up for Osaka race, never went. Many years neglect etc.

Thanks for that. That mast looks identical. Electra 2 was professionally rigged and tuned. Most of us mere mortals would not dare to use the rig tension this boat has on the cap shrouds.
After an on the water conference today it seems the sail numbers don't match those on the spinnaker so we have to presume the main sail is off another boat. A sail recut is on the cards and the sailmaker can sort out the luff round. Now that we know Pippin has the same mast with the same bend we can search out photos.

Pippin is currently moored in Elizabeth Bay, Sydney. Not sure on the owners details. I crewed on her 1998-2002 which included the 1998 S2H when she owned by David and Ann Taylor.

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Charriot said..

Ramona said..

Charriot said..


This my last boat Farr 37.Pippin..it looks the mast has identical bent .Pippin was professionally tuned, before Sydney Hobart race, as she was winner in her category. Later fully set up for Osaka race, never went. Many years neglect etc.

Thanks for that. That mast looks identical. Electra 2 was professionally rigged and tuned. Most of us mere mortals would not dare to use the rig tension this boat has on the cap shrouds.
After an on the water conference today it seems the sail numbers don't match those on the spinnaker so we have to presume the main sail is off another boat. A sail recut is on the cards and the sailmaker can sort out the luff round. Now that we know Pippin has the same mast with the same bend we can search out photos.

Nice picture, newer seen it.Lovely to sail, wonder where is now. Sold it 3 years ago.

There is a nice looking blue one at Lake Macquarie near Wangi owned by a guy who lives in Canberra which had an extensive refit about 3 years ago and also has quite a large sugar scoop extension. Haven't sailed the lake for a while so I guess I should say it was still there up to two years ago.

Have made a few Farr 37 sails. It was originally designed as racing boat and hence the prebend.
A few had runners and checkstay but these were generally dispensed with as the design became more club racing/ recreational in use.
I would not reduce the pre bend too much, some easing of caps maybe? To reduce to +100mm.
I would not go beyond this as may make the mast a bit wobbly and the last thing we want is to have the mast invert falling off big wave(s) and come tumbling down.
Recut the main ( messy and expensive but possible $700-800 and looks like an old sail) or replace it, but please use someone who understands sail design and not cookie cutter production!

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Galatea said..
Have made a few Farr 37 sails. It was originally designed as racing boat and hence the prebend.
A few had runners and checkstay but these were generally dispensed with as the design became more club racing/ recreational in use.
I would not reduce the pre bend too much, some easing of caps maybe? To reduce to +100mm.
I would not go beyond this as may make the mast a bit wobbly and the last thing we want is to have the mast invert falling off big wave(s) and come tumbling down.
Recut the main ( messy and expensive but possible $700-800 and looks like an old sail) or replace it, but please use someone who understands sail design and not cookie cutter production!

My first suggestion was to get him to give you a call and get a new mainsail made. He is in a bit of a rush to head North and wants to use this one for now. It's obviously the wrong sail and does not have any roach like the other 37 sails in photos. The luff is perfectly straight on this sail. I have not talked to him for a few days but I think he has unpicked the boltrope but not done any cutting yet!
Any suggestions greatly appreciated.

If he goes north with it, reef early. Helps with the lack of luff Curve.

If he goes north with it, reef early. Helps with the lack of luff Curve.

My mate with the Farr 37 refitted the mainsail yesterday. I waited till all the work was done and then wandered over. He unpicked the luff tape and laid the sail out on the ground and using lengths of electrical conduit marked out the new luff curve. I think the luff round he used was 110mm, he just eyeballed the distance from the deck. The maximum bend in the mast was just below the second spreader, well above the middle of the luff. He lost a bit of sail area and had to make a new set of cringles. The cringles he made from 38mm stainless tube after turning up a pair of dies on the lathe and pressing them in his hydraulic press. The foot of the sail is a bit shorter now too and the clew arrangement will need some work. In the photo he has no tension on the Cunninham eye and the foot is too tight. I was amazed at how good it looked!

Well done