In-mast furling - conversion back to slab?

[GTFC]

My boat has a fully battened main and bat-cars on a track. I recently took a family on my boat, they had just sold their boat (with in-mast furling) on which they crossed the Atlantic. At the end of the journey we sailed up to the mooring on the main alone and dropped the main, they were stunned how easy it was (yes it is a pig to raise the thing without battens getting caught in lazy jacks!). They were also surprised that a cruising boat could sail at 45 degrees off the wind.

Hi, with a decent in mast mainsail, fully battened and both jib and mainsail correctly, set 45° shouldn't be too difficult to achieve...
Raising and dropping the main isn't really the challenge for me, sailing either short handed, inexperienced crew or solo, it's reefing up and down is the crunch time, and for me in mast offers the most practical and secure solution...correct boom angle, tack and sheet tensions in place...
But each to their own preferences, experiences and situations
Less roaring and more easy going for me?

 

[roaringgirl]

Hi, with a decent in mast mainsail, fully battened and both jib and mainsail correctly, set 45° shouldn't be too difficult to achieve...
Raising and dropping the main isn't really the challenge for me, sailing either short handed, inexperienced crew or solo, it's reefing up and down is the crunch time, and for me in mast offers the most practical and secure solution...correct boom angle, tack and sheet tensions in place...
But each to their own preferences, experiences and situations
Less roaring and more easy going for me?

Reefing is easier than raising it in the first place as I don't have to get the battens past the lazy jacks.

It occurs to me that in-mast furling means the sail lacks horizontal battens, a kicking strap and a Cunningham and the halyard tension can't be adjusted. This must make it harder to get good performance out of the sail in different conditions? If you're already getting good performance then surely it would be even better with these trim tools that you lack?

 

[Baggywrinkle]

There really is a lot of tosh written here about in-mast furling.

Not sure I suggested any of that, but regardless, having a sail up adds top weight, whether the designer considered it in his calculations or not.

A few years ago an Oceanis 40 capsized in the Biscay, drowning a crew. The subsequent inquiry determined that the furling gear and other add-ons, not part of the original stability calculations, had contributed tho the low AVS and subsequent capsize. I'm not sure the OP posted his boat type or when it was designed and built.

That said, I have every confidence that both Farr and Frers spec their current designs properly and account for such things.

Are you referring to the Oceanis 390 "Ocean Madam"? I can't find any others that fit your description. If that is the boat you are referring to, it was knocked down twice by breaking waves - it lost the rigging on the second inversion, and the washboards fell out causing downflooding - there is also the suggestion that the hatch may already have been open allowing both downflooding and loss of the washboards. On the second knockdown it took a long time to right again. There was no mention in the report of in-mast furling having anything to do with the accident, only that at the time of the incident, there was no stability information available to the skipper to assess the dangers of crossing Biscay in a forecast F9 - the boat was built in 1989, before the RCD was in force, and the stability info supplied by the manufacturer at the enquiry was for the hull only, not including the deck.

https://assets.publishing.service.gov.uk/media/547c71bb40f0b6024100014d/Ocean_Madam.pdf

.... and then there a people who have two masts, two furlers and two traditional sails up top - bet that weighs a fair bit more than my fractional fully furling rig

 

[Laminar Flow]

There really is a lot of tosh written here about in-mast furling.


Are you referring to the Oceanis 390 "Ocean Madam"? I can't find any others that fit your description. If that is the boat you are referring to, it was knocked down twice by breaking waves - it lost the rigging on the second inversion, and the washboards fell out causing downflooding - there is also the suggestion that the hatch may already have been open allowing both downflooding and loss of the washboards. On the second knockdown it took a long time to right again. There was no mention in the report of in-mast furling having anything to do with the accident, only that at the time of the incident, there was no stability information available to the skipper to assess the dangers of crossing Biscay in a forecast F9 - the boat was built in 1989, before the RCD was in force, and the stability info supplied by the manufacturer at the enquiry was for the hull only, not including the deck.

https://assets.publishing.service.gov.uk/media/547c71bb40f0b6024100014d/Ocean_Madam.pdf

.... and then there a people who have two masts, two furlers and two traditional sails up top - bet that weighs a fair bit more than my fractional fully furling rig

I'm not denying that contemporary furling systems offer convenience and when reliable a degree of safety. However, nothing, in technical terms, is for free:

Firstly, any furling sail will be less efficient, that stands to reason, you simply cannot roll up a 3 dimensional complex surface in two dimensions. The longer the foot on a jib, the worse the furled shape. On a main sail without a roach you are sacrificing SA and the top of the triangle behind the mast is made less effective by turbulence over the ever shorter cord..

Secondly, any furling system adds weight aloft, question is how much?
On a 40' boat the main weighs about 15kg and the furler around 18kg with a combined VCG of 7.3m. This gives us a negative moment of 249 kg/m. In a masthead rig with an additional furling genoa it would be twice that, i. e. 500kg/m or 3600ft/pounds in old money. To compensate you would have to add 393 kg to your ballast.
Now you could argue that you still need your sails to go anywhere, so in this case a non-furling main would weigh 18kg less or have 153kg/m less heeling moment. The real issue comes when the yacht is proceeding with both genny and main furled, in high winds under trysail and storm jib, just when you really would want to keep all that weight low. In a 40' boat, sails and furling gear account for 20% of the total weight of the rig, of this the furling gear alone accounts for 70%.
On smaller boats, that are inherently less stable, the figures are less favourable still.

Does that mean we cannot design a boat that can stand up to it's furling gear? Of course not, it is just another thing to consider that doesn't contribute to stability or performance (As I had said, no more no less).

So, can we trust the designers, builders or the RCD for that matter? Just take published displacement figures for example. Displacement is the single most important figure governing performance, comfort and safety, yet there is absolutely no consensus on what that actually means: design weight, building weight (usually and at times considerably more than designed), empty weight, half load, cruising load and if so coastal or offshore, and then there is liveaboard? Now that boats "appear" to be getting lever lighter, the BA/D ratios are also getting lower and with the entire industry remarkably coy about disclosing real figures, one does have to wonder.
On the up-side: most rigs are designed with formidable safety factors, most sailors never go offshore or sail in adverse conditions and most boats, statistically counting, are only ever moved three days a year.

 

[tedcanada3000]

I have sailed quite some distance on a 42 ft boat with an in-mast main, but an external trach fitted just to one side of the sail slot for the inmast main. We used a fully battened slab-reef main for racing on the external track, and for cruising or heavy weather just used the internal furling one

Please let me know the detail on " fully battened slab-reef main on the external track" because I'm considering the parallel usage, a fully battened main on external track as primary, and in-mast furling as secondary.
Currently, the latter only on an old 34ft yacht with Selden mast.

 

[sailingmartin]

This may be a numpty question, but is it possible (and financially viable) to convert an in-mast furling (1980's selden) mast back to using conventional sails? I am not comfortable with the idea of old in mast furling systems for an extended cruising boat, but one of the otherwise desirable boats that I am looking at has in-mast furling. Changing the mast would, I suspect, be excessively expensive.

Neil,
I had an EasyReef bolt on furling system converted back to slab reefing after if failed (was nearly 30 years old). This was a fairly simple procedure as the original mast lay underneath with the right slots for the mainsail. The main expense was the new sail. As you said, a new mast is very, very expensive. Try talking to Allspars (branches in Plymouth and the Solent) and I am sure they will be able to help with your identifying your mast as they are Selden agents. Good luck.