Strange skeleton frame mast

[Elie]

Such mast gives serious avantatage, for the main sail. Close hauled, the mast windage creates a big turbulence that renders a good portion of the mainsail useless. A latice mast eliminate all that windage and add horsepower when beating. I wonder if a carbon fiber mast of that sort would be an outstanding solution...

[topmast]

Seems like a lot of unknown risks even if it is cheap. But not as inexpensive a a good fir or spruce from the woods. Big gaffers need fir but easy to find 70' spruce for a marconi rig. Just gotta live in the better part of the world . Used to set up those antenna in the Arctic and they folded with dependable regularity come windy.

[OzClipper]

Mk has raised a good point, lots of welds by unknown individuals , probably no history of test records, expensive to build and I would doubt that they would be lightweight as compared to a foiled extrusion.

[Schooner Chandlery]

Wow, I can't imagine a cruiser wanting one of those. I worry enough about corrosion failures and weld problems as it is! And yes it seems like it would be a bad bit of turbulent airflow around that thing too.

[captlloyd]

Originally Posted by mkriley

That lattice mast is just as strong as it's worst weld.
How many welds do you think are in the mast in the picture?
mk

A good 3/8" inch of weld will easily support 6-7 hundred pounds. Do the math, each joint probably has at least 2" of weld. As a professional welder, making numerous good welds is not an issue. Boring, maybe, substantial, no. Steel be strong!!

[Stumble]

Originally Posted by captlloyd

A good 3/8" inch of weld will easily support 6-7 hundred pounds. Do the math, each joint probably has at least 2" of weld. As a professional welder, making numerous good welds is not an issue. Boring, maybe, substantial, no. Steel be strong!!

And compression loads on a mast can be rated in tens of thousands of pounds, with a single bad strut attachment off by just a 1/4 inch leading to point loading and stress risers that could cause the whole thing to collapse. It isn't just ever weld that needs to be perfect ever crossbar needs to be cut to the perfect length, every bevel needs to be spaced correctly....

I have no idea how fault tolerant this type of structure is relative to it s difficulty in construction, but I just don't see the draw.

[Stumble]

Originally Posted by Elie

Such mast gives serious avantatage, for the main sail. Close hauled, the mast windage creates a big turbulence that renders a good portion of the mainsail useless. A latice mast eliminate all that windage and add horsepower when beating. I wonder if a carbon fiber mast of that sort would be an outstanding solution...

You have it backwards. A normal mast help smooth the air flow onto the mast and reduces turbulence, which is why they are use daily instead of round sections. A lattice like this is going to generate massive amounts of drag by comparison. Every single connection point is going to generate large vortexes, the round profile of the tubing is terrible for aerodynamic drag, and the size of it is going to have to be thicker than an aluminium mast would need to be.

A full engineering explanation is beyond me, but the drag coefficient of a teardrop mast can be as low as .04, while the coefficient of a circular tube is .47 so the round tubing could generate as much as 12 times as much drag depending on the relative surface area. More realistically an elliptical mast will generate about 1/5 the drag of a circular mast with the same frontal area (same athwartship dimension).

This is a huge advantage to the elliptical mast. Even given the cut outs in the lattice mast probably doesn't help enough. Instead of one large ellipse youhave three times as much round tube length just for the uprights. The total surface area is possibly even higher than for the standard mast.

[hsi88]

Our galvanized TV mast finally came down (and hit my car) after 40 or so years of service. Broke right where it was cemented into the ground. Have a friend who is going to use it for another 40 years. Will just be a tad shorter than before. And the step welds are still strong!

[Sandero]

Originally Posted by Stumble

You have it backwards. A normal mast help smooth the air flow onto the mast and reduces turbulence, which is why they are use daily instead of round sections. A lattice like this is going to generate massive amounts of drag by comparison. Every single connection point is going to generate large vortexes, the round profile of the tubing is terrible for aerodynamic drag, and the size of it is going to have to be thicker than an aluminium mast would need to be.

A full engineering explanation is beyond me, but the drag coefficient of a teardrop mast can be as low as .04, while the coefficient of a circular tube is .47 so the round tubing could generate as much as 12 times as much drag depending on the relative surface area. More realistically an elliptical mast will generate about 1/5 the drag of a circular mast with the same frontal area (same athwartship dimension).

This is a huge advantage to the elliptical mast. Even given the cut outs in the lattice mast probably doesn't help enough. Instead of one large ellipse youhave three times as much round tube length just for the uprights. The total surface area is possibly even higher than for the standard mast.

Be serious.... practically most masts on non designated race boats have all manner of "things" attached to the forward edge of the mast... lights, tracks, radar, pols and even halyards.

[El Pinguino]

On the positive side... lattice masts make truly brilliant radar reflectors.

[Don C L]

But maybe they are more stealthy! Like owl wings perhaps?
https://asknature.org/strategy/wing-.../#.WLjJ3iMrInU

[El Pinguino]

Originally Posted by Don C L

But maybe they are more stealthy! Like owl wings perhaps?
https://asknature.org/strategy/wing-.../#.WLjJ3iMrInU

The fact that owl wings are silent is pure coincidence.... they are in fact designed that way to be highly visible on bat radar.

Imagine the carnage in the night skies of the bats couldn't see the owls.........

[2020]

Originally Posted by GordMay

Greetings and welcome aboard the CF, 2020.

Thank you Mr May.
I've long enjoyed CF and it's a pleasure to join.
Thanks to all for the comments so far - as usual, I'm now expertly confused.

[IslandHopper]

A couple more interesting applications of lattice work, for some reason the boom seems kinda neat to me, not that I would ever have one though

[CK JAGUAR]

The top images appear to be of Sylfia out of New Zealand. Apparently the builder had no knowledge of all the air foil problems, risks and hazards of using such a rig. Sylfia was his last and he built her for his family about 10 years ago. She already has thousands of ocean miles behind her. Her builder was a Polish mining engineer who built four different ships, all using lattice work masts. He circumnavigated with them 3-4 times. Sylfia was the last. Sylfia is 75 feet. The largest was 80ft. ALL of them had lattice masts and none had problems. He was an amazing man. And clearly he would have had no time to read these very knowledgeable forums. He was far too busy sailing the world.

The current owners have already covered over 2000 ocean miles onboard. See "Sailing Drenched". Or read this: https://sylfia.org/about/