Making a "Park Avenue" Boom

[Meanz Beanz]

Originally Posted by waikikin

That boom looks groovy Meanz Beanz & if wide enough would make like a stretcher hammock & even better with some cushions, imagine kikin' back in that as you harness the powers of the elements, but you might find it "interacts" with the shrouds when sheeted out, butterfly frames of staino or alu tube with or without the fabric work nice & 2 or 4 "wings" leaving out the bit of boom in line with the shrouds may be the way to go esp' if you've got the original boom, although I do like the boom you've shown heaps. Regards from Jeff

LOL yeah if the boat was big enough that would be great!

Being a cat the boom rarely meets the shrouds, you tend to reach everywhere as its quicker! In fact I must admit I don't know if the mainsheet goes far enough!

Still puzzling over this one.

Cheers
MBz

[Meanz Beanz]

Originally Posted by DanishBagger

How about a boom shaped somewhat like a windsurfer-boom - you know, like a compressed oval. You could use cloth or string between the two poles - string would be enough to hold the sail, but the cloth would work as an "end-cap". Heck, if done properly, the sail-cover could double as the end-cap by simply having it on top of the strings.

This way you could propably make it just about the same wight as the boom you have now, and you wouldn't have struts sticking out, wating to hit you in the eye.

Now thats a thought!... I will have to get the sketch pad out and doodle!

Thanks

MBz

[Meanz Beanz]

Originally Posted by alan white

Yeah, struts would impale the unwary. The split boom, with a couple of cross-bars, is a good idea. Unzip, drop the sail, zip back up. Tramp webbing under.

Sounds reasonable for my boat ! Misses out on the water catching idea but for a small cat it is light weight and practical.

Cheers
MBz

PS. Sorry about the tardy replies... emails not getting to me????

[eponodyne]

I kind of like Alan White's idea (great minds think alike, and hey, ours do too...); build it exactly like the wing tip of a tube-and-rag homebuilt airplane. You could even use Ceconite to cover!

[scupper]

I've been thinking of building one of these. Mainly I'm concerned with ease of building and I'd rather it never broke. So far the plan I've come up with is, for my 300 square foot main with a foot of just under 14' would be to find a nice piece of aluminium angle iron, like 8"x8" probably 3/16" or 1/4". Weld some flat bar or some plate across the hypotenuse of the triangle, along it every six inches or so. I figured this would be something I could have a shop weld up for me in a half hour or so if I just cut all the gussets out. For my reefing blocks I was thinking I could just run a bolt horizontally though the angled sides of the boom and just make some some beveled bits of plastic to tighten the nut against,you could put the sheave on the bolt and I guess you'd have to pop rivet some cheeks around each sheave. But this would get rid of the issue I've being having about whether I run my lines inside or outside of the boom. This would let me just run them along the inside of the boom which would be pretty much open except for the flat bar every six inches. My current boom is five inch sch. 40 pipe so an 8x8 would be much of a change.
If anyone's still following this thread I appreciate your thoughts.

[scupper]

Another thing that pointed me in the direction of a wide boom was I remember reading in some sail trim book that having a wider boom along the foot helps to seal in the surface pressure along the sail rather than just to let it spill out over the foot and so helps to keep in the lift. Much like wing tips on a plane of a keel for that matter.

[michael pierzga]

Didnt read all the replies but a simple " T " shaped boom is also elegant and simple to build. The structural part of the boom is a vertical box section , tapered in the ends. The "T" , horizontal section wings , are a secondary structure to hold the lazy jacks and give a platform for the flaked main to rest The T boom is simple because all the reef lines can be led on the outside of the main boom structure and the " wings can be a secondary bond because they carry little load..

Lazy jacks on " spreaders " growing out of the side of the boom to give a nice platform for the main to flake never work well. Spin sheets and lines catch the lazy jack spreaders , the flaked sail sags between jacks , reef line get tangled......