Getting a mast on a boat WITHOUT a real crane

[MicHughV]

Chotu,

Was just thinking....
If your mast is 60' long, plus the the mast location is another 8' above the water....that puts you at 68'...not including any lights, antenna's, etc...

The bridges on the ICW have a 65' clearance, with the exception of the Julia Tuttle Bridge in Miami which has 56'...

Not sure where you are located, but trust you have considered this.

[Chotu]

Originally Posted by MicHughV

Chotu,

Was just thinking....
If your mast is 60' long, plus the the mast location is another 8' above the water....that puts you at 68'...not including any lights, antenna's, etc...

The bridges on the ICW have a 65' clearance, with the exception of the Julia Tuttle Bridge in Miami which has 56'...

Not sure where you are located, but trust you have considered this.

I guess the mast is actually 64 and I’m putting a 6ft extension on it. I’ve been away from the boat a while.

This is an outside boat, unfortunately. I’d still love to do a tabernacle type thing but I need to get this boat done at this point.

My plan for any bridges I need to get under is to get the mast pulled. So if I want to motor the ICW, I’ll pop off the mast for the whole trip and do it fast. Sane if I want to go far inland.

Sucks, but I don’t want to be underpowered.

PS: I think these numbers are correct, but I’m a little foggy on it.

[MicHughV]

that is a bit beyond my pay scale.....the mast height on the Bennie is only about 55' above the water...

[Chotu]

Originally Posted by MicHughV

that is a bit beyond my pay scale.....the mast height on the Bennie is only about 55' above the water...

Payscale, nothing. Ha ha. The mast was $6000 including boom, stays (which I’m replacing), some winches, mainsail, jib furler, jib and a traveler I’m replacing because everyone here convinced me it was too short to be useful.

I do also have to do the 6ft extension. I’m hoping I can just roll up some sheet aluminum to the correct profile to do the extension. It’s at the base of the mast, so it’s not in a bendy area. Just needs to support the in column pressure for the most part.

[rslifkin]

Originally Posted by Chotu

I guess the mast is actually 64 and I’m putting a 6ft extension on it. I’ve been away from the boat a while.

This is an outside boat, unfortunately. I’d still love to do a tabernacle type thing but I need to get this boat done at this point.

My plan for any bridges I need to get under is to get the mast pulled. So if I want to motor the ICW, I’ll pop off the mast for the whole trip and do it fast. Sane if I want to go far inland.

Sucks, but I don’t want to be underpowered.

PS: I think these numbers are correct, but I’m a little foggy on it.

A full tabernacle is probably tough with a mast that big, but I'd talk to some riggers about hinging, say, the top 10 feet (post-extension). If it's a fractional rig, maybe hinge just above the forestay. That would give you a section that's easier to drop and gives you ICW clearance easily enough. Save the big mast drops for going further inland.

[Chotu]

Originally Posted by rslifkin

A full tabernacle is probably tough with a mast that big, but I'd talk to some riggers about hinging, say, the top 10 feet (post-extension). If it's a fractional rig, maybe hinge just above the forestay. That would give you a section that's easier to drop and gives you ICW clearance easily enough. Save the big mast drops for going further inland.

You are a genius! That’s a great idea to look into. I’ll check it out.

[MicHughV]

Chotu,
I've told you on a number of occasions, that I am a retired structural marine engineer.
The compression loads on the mast, and tension loads on the rigging can be significant, especially so on a 50' cat, even when at rest. You will also have wiring inside the mast, and perhaps halyards as well..
Having a hinged connection, 10' from the top of your mast, with only, presumably, a backstay running to the top of the mast, or perhaps some runners, in addition to shrouds, while it sounds like a grand idea, will likely be unworkable for a number of reasons.
How will the main get hoisted beyond the hinge point ?
I will be interested to hear the results of your conversation with any rigger, but I'm pretty confident, I know what their answer will be..

[Chotu]

Originally Posted by MicHughV

Chotu,
I've told you on a number of occasions, that I am a retired structural marine engineer.
The compression loads on the mast, and tension loads on the rigging can be significant, especially so on a 50' cat, even when at rest. You will also have wiring inside the mast, and perhaps halyards as well..
Having a hinged connection, 10' from the top of your mast, with only, presumably, a backstay running to the top of the mast, or perhaps some runners, in addition to shrouds, while it sounds like a grand idea, will likely be unworkable for a number of reasons.
How will the main get hoisted beyond the hinge point ?
I will be interested to hear the results of your conversation with any rigger, but I'm pretty confident, I know what their answer will be..

I’m sure you’re right. I was trying to picture how you’d raise and lower a top pivot like that too. Rslifkin is still a great thinker and has come up with a lot of winners, even if this one doesn’t pan out. You are too. I remember my thread on the roof support columns and davits. You both added a lot to that project. They are installed and doing well.

I look forward to your participation in the rest of the threads on the rigging. It’s going to be all DIY I think. I need to get some chainplates, install them, change the length of the spreaders a little bit (because I’m raising the mast 6ft at the bottom), get a bow tube/beam installed and ready for the forestay load, work out the angles and lengths for the new shrouds and forestay (there is no backstay). Then run all the controls to my “sail control table.”

[Tayana42]

Perhaps something like a sliding Gunter rig could be devised? I have never seen anything like it on a cat but perhaps…

[MicHughV]

Sure, Chotu, bring it on, lets get that Cat rigged....I wanna go a for ride !!!!
Be glad to throw my 2c in wherever I see you going left instead of right.

I had a coastal ride on a 50' tri once, that was a very interesting experience. No question, your boat will likely have a good turn of speed.

[MicHughV]

Just for grins....I dug up my old mast transport pic...I didn't use this mast on my boat, but hauled it for someone else.

I gotta tell you, building my boat was probably the best three years of life. I accomplished much, with very little.

Seeing you go thru' similar experiences is a blast.

[Chotu]

Originally Posted by MicHughV

Just for grins....I dug up my old mast transport pic...I didn't use this mast on my boat, but hauled it for someone else.

I gotta tell you, building my boat was probably the best three years of life. I accomplished much, with very little.

Seeing you go thru' similar experiences is a blast.

Nice!!! Looks just like my mast right now. It’s sitting on a similar trailer I drove it back with.

I’m glad you’re enjoying the build!

[Auspicious]

Originally Posted by MicHughV

I've told you on a number of occasions, that I am a retired structural marine engineer.

Naval architect and marine engineer here. I agree with MicHughV. Just not a good idea. Hinging at the base of the mast (assuming deck stepped) is much more achievable. I know of a 60+' ketch that has hinged the main mast to fit under bridges on the ICW. It's a painful process that takes many hours but does not require any outside support.

[MicHughV]

Auspicious, yes, I can see that as a more workable idea. The mast shoe can be fabricated as a hinge, but the two hinge plates should lay flush with each other, so that all mast compression is uniform, and the lower hinge plate is flush with the deck/mast support.. ...The logical placement of the actual hinge should be on the aft side of the two plates, so that the mast can be rotated backwards. A fab shop can probably come up with something made from s/s.
Were it me, I'd also contrive to have a spinnaker pole or some other long pole made to fit on the front side of the base, to be used as a " lever arm" as the mast rotates backwards. This way a halyard can be led to the end of the pole and fixed there, and an anchor line or other lines also led to this location and then to a winch. The shrouds should be able to keep the mast centered.
I'd have to do some math to figure out how much the masts needs to rotate to clear a bridge, but all in all, some possibilities here.

[Auspicious]

Originally Posted by MicHughV

Auspicious, yes, I can see that as a more workable idea.

We are on the edge of a lovefest here. *grin* Fully agree. So two professional opinions from people who don't know each other who are on the same page.

The only thing more useful is two professionals who don't agree who engage in a civil discussion to figure out how their underlying assumptions differ.

TL;DR: Don't hinge the top of the mast.