That’s an interesting idea that it might be possible to retrofit. I have also seen outriggers and racks fabricated out of SS tube, but don’t like that much because of how much they would injure someone they hit, even lightly.
Concerning injury, not sure it matters much what part of the boom hits you – the consequences are horrid no matter what – whether your neck gets broken by the boom, or the brain gets banged up makes very little difference – the outcome is the same
I disagree. In fact I don’t like adding any protrusions to the boom. My thinking is that a boom injury is not always catastrophic—could even just be falling into it, or a light brush in a tack—so my thinking is that adding stuff sticking out is upping the injury potential.
I guess it depends on the circumstances. We ended up setting the boom well above head height for that reason.
However if you consider the striking surface of the boom in the picture at the very top, I don’t think it is any different from that of a 25 or 30 mm pipe. So, if blunting the blow is the objective, perhaps neither should be used and we should stick to the regular shape.
The pic at the very top is, as I wrote in the post, in my view, far less than ideal. Instead look at the carbon boom from Offshore.
Svein Hellesø
July 21, 2023 5:08 am
In addition to the advantages in controlling the sail on top of the boom, there might also been an aerodynamic advantage in that the wider boom acts as an end plate for the main sail reducing pressure spill over from the windward side.
Apparently very important in some cases (Americas Cup etc. where the deck acts as a big endplate), but for a cruising boat maybe mostly a small added bonus.
That’s another point in favour, although with today’s loose footed mains there is probably room, depending on how tight the outhaul is and the shape of the foot, for the air to cross sides. Anyway, as you say, not a big deal for a cruiser.
George L
July 29, 2023 5:25 am
Hi John
we priced this out in aluminium, it was more than the boom itself and I was not enamored by the look (though you can sleep up there when its really hot and the sail isn’t up. Also it reduces how far you can let out the sheet before the boom hits the shroud
Our solution was to have three bars each on the boom spaced so none would hit the shroud. These are kind of three dimensional – with a support in the center, so nothing will bend. Good old triangles …
I still think that a Carbon V boom is the ultimate option. I talked to Hall Spars about this and they had looked at the loads carefully and determined that it was difficult to do a V boom elegantly in aluminium. Perhaps that’s what you ran into.
Also, I have never seen a boat where the boom gets even close to the shroud before the sail starts to chafe unacceptably on the shrouds and spreaders, so I can’t see the V boom being the limiter for letting the sail out.
And finally, I have seen outriggers and at least to me they are both ugly and pose more danger of hurting someone than a smooth boom.
you can do much more, shapewise, with carbon than with aluminium (which was the option we considered – Sparcraft France) and they look quite good on large yachts, IMO. We didn’t bother carbon for the boom because the weight penalty of an alu boom is much less than that of an alu mast.
point taken.
concerning ugliness etc. we decided this on the basis of drawings and it looked ok to us – ugly did not come to mind, but that’s in the eyes of the beholder. to us the benefits were bigger, light weight and doing the job. I commented concerning the danger above, but we may agree to disagree on that one.
I have seen a similar idea but the shape fabricated from tube along the boom.
Hi Alastair,
That’s an interesting idea that it might be possible to retrofit. I have also seen outriggers and racks fabricated out of SS tube, but don’t like that much because of how much they would injure someone they hit, even lightly.
see comment above.
I wouldn’t use stainless.
Concerning injury, not sure it matters much what part of the boom hits you – the consequences are horrid no matter what – whether your neck gets broken by the boom, or the brain gets banged up makes very little difference – the outcome is the same
Hi George,
I disagree. In fact I don’t like adding any protrusions to the boom. My thinking is that a boom injury is not always catastrophic—could even just be falling into it, or a light brush in a tack—so my thinking is that adding stuff sticking out is upping the injury potential.
Hi John,
I guess it depends on the circumstances. We ended up setting the boom well above head height for that reason.
However if you consider the striking surface of the boom in the picture at the very top, I don’t think it is any different from that of a 25 or 30 mm pipe. So, if blunting the blow is the objective, perhaps neither should be used and we should stick to the regular shape.
Hi George,
The pic at the very top is, as I wrote in the post, in my view, far less than ideal. Instead look at the carbon boom from Offshore.
In addition to the advantages in controlling the sail on top of the boom, there might also been an aerodynamic advantage in that the wider boom acts as an end plate for the main sail reducing pressure spill over from the windward side.
Apparently very important in some cases (Americas Cup etc. where the deck acts as a big endplate), but for a cruising boat maybe mostly a small added bonus.
Hi Svein,
That’s another point in favour, although with today’s loose footed mains there is probably room, depending on how tight the outhaul is and the shape of the foot, for the air to cross sides. Anyway, as you say, not a big deal for a cruiser.
Hi John
we priced this out in aluminium, it was more than the boom itself and I was not enamored by the look (though you can sleep up there when its really hot and the sail isn’t up. Also it reduces how far you can let out the sheet before the boom hits the shroud
Our solution was to have three bars each on the boom spaced so none would hit the shroud. These are kind of three dimensional – with a support in the center, so nothing will bend. Good old triangles …
The lazyjacks go to the outside of the bars.
Same benefits, cheaper, lighter, no problems.
Hi George,
I still think that a Carbon V boom is the ultimate option. I talked to Hall Spars about this and they had looked at the loads carefully and determined that it was difficult to do a V boom elegantly in aluminium. Perhaps that’s what you ran into.
Also, I have never seen a boat where the boom gets even close to the shroud before the sail starts to chafe unacceptably on the shrouds and spreaders, so I can’t see the V boom being the limiter for letting the sail out.
And finally, I have seen outriggers and at least to me they are both ugly and pose more danger of hurting someone than a smooth boom.
you can do much more, shapewise, with carbon than with aluminium (which was the option we considered – Sparcraft France) and they look quite good on large yachts, IMO. We didn’t bother carbon for the boom because the weight penalty of an alu boom is much less than that of an alu mast.
point taken.
concerning ugliness etc. we decided this on the basis of drawings and it looked ok to us – ugly did not come to mind, but that’s in the eyes of the beholder. to us the benefits were bigger, light weight and doing the job. I commented concerning the danger above, but we may agree to disagree on that one.
I am not in a position to replace the boom on my Bristol 35.5 but I had a stainless catchment fabricated that helps immensely. My lazy jacks attached directly to it. It serves as a great hand hold when reefing. As the sail is loose footed and the sheeting is mid boom it also strengthens the boom. https://lh3.googleusercontent.com/pw/AIL4fc8VHOq6pAAeQLnz7Gztr4SWP_0LLnRvalMIrFM_bBHwCTfrob_RZLdSLOpEKVY0eyQEgDwJn2GjlCSpcEnn3hN68nSQsnitIGU29jJy0U8bOmRDfqxZQToz2bY0QzTU7kcMaxoGgP6H8AuVxzwilQi0VCkgm6Zm1VhDZZy4VGUYtTQ9loMN2CKYh1qzqS1MnEq_hKEVa51V04oWNvv6tyyBo0HrGLmTSxN8entTL-5OwINUGgGGjV4IKXS8JIOZwSfqyAsWV33-VvK6NY-WUuEaJqbFYet3eeXgEDR3Lf7W7o4mJ7XYXDeJUBKkq-MTlRMP5YWjxTCm_1JZ7WcEVPEonSWsD3phVUZKYvIeieRdquyW5WLmxz1aj68Vrklx1Hw6zImr49O-F5qa-_dVBphWiNaM01XVHve9xuwTnwk0VRiKdRmgNmypwE81PTQF3Hu8An3LH5nnsZdwcY1yEMLAS2xbl021kZklX6OHLZIt6PGJcNqE-fGhLVcaxxd_g3ter8aw_R4JbOmEZcZKxpyFNbECxTPlupVFMk7HXPqDlMroMW-Rd3rrFsBr_7m25eZcTomcTFDdMsKTesaftt3fyP4emSuNh8csfjamTbXwX39v8npM8K_WgsHimTSiwNEb-H9iJ-SDEXJrH9NVbk77Dp46RuspPUy6HNqRC3Y5a4Z4DPek1dnYCwm4ywWA-YwSInmd5DH99QDoAoohk_ySat7_snFWdrgb3FPHxWbFVRYSpIKJjd_txEQ_-fEQEIt_qoimrym1OOyzKW0FdO_mmCrJ55AScdmKgZAg-hCh4Lt7uuk5STGd3OYSKE03l3jQlDlEaR_U4TByJTC4i0ALebfJA-52wchw4bi25gN0z-B7jPhQpjT8LURJZtwXWXHEcSlJ1WCuIW1czkH_FFI=w523-h649-s-no?authuser=0
Hi David,
Good to hear from you again. However, the links you provided are not accessible. That said, you can now upload a photo to the comments here: https://www.morganscloud.com/2013/11/10/aac-comment-guide-lines/