Mast Step Rigging

[pollyvon]

Pacific Seacraft 31 Mariah mast stepping with hinged mast step. Because my chainplates are lower than my mast step, was considering using a shroud bridle and jin-pole to step mast.

Instead of puling on the mast, pull on both aft shroud cables (with a split bridle) while they are attached to the chainplates. The shrouds under tension would provide athwart ship stability to the mast as it is raised and the attached back stay would stop the mast in it's upright position. A halyard would support the jin-pole and also keep the shrouds bridle from sliding down the shrouds as the mast is raised.

It would seem that this is a safe way to step and unstep the mast without an external crane.

Appreciate any feed back on this thought.

[deltaten]

Having recently done virtually the. same.....
Have backup plan!
Fortunately, mine was'nt damaged when it hit the dock!

[mf70]

#1: Make a model and think this through.
#2: Setting up temporary shrouds to bridles set to provide a pivot at the same height would let the shrouds stay functional during the hoist.
#3: Gin pole will also need shrouds.
This worked for me on a 26' Bristol. Your mast will be a LOT heavier.

Sent from my GT-P3113 using Cruisers Sailing Forum mobile app

[Blue Stocking]

Bruce Bingham has detailed drawings and text on this subject in " The Sailors Sketchbook" ISBN 0-915160-55-2 . 2nd only to Chapman's--imho.

[deltaten]

Impetus supplied by $400 marina fee to R&R the mast.
Specs and technique. as seen on Hake/Seaward RK32 video.
Hmmm? How hard could it be? '
Only issue I coudd see, after the. drop, was that my side-loops should have been less stretchy and tighter. Same for the gin pole bracing/stays. Seems that "stacking tolerances" of give allowed the mast assbly to. rotate enough to slip it's bouandaries.
The lashing. holding the. mast base in place and the. boom-as-ginpole were sound. The Sta-Set jib sheets as side guys *could* have been tighter and probably need to have a way to increase tension as needed.

Great in theory; only lacking (in my case) in practice/application. I could have made better use of ratchet-straps and solid-er (izzat a word?) side attachments.

HTH,
Paul

[Blue Stocking]

Not to be-labor the point, but if you have forward lower, a pendant from the main shroud attachment point, to the fwd ch/plate geometry, can keep the shroud tensioned. Bruce explains and draws it all completely.

[Dennis.G]

If I understand your idea right, I think the split bridle may be a mistake. If mast starts to move to one side a split bridle will just move with it. You might maintain the same tension of both shrouds, but that does not mean they will hold the same distance.

On my Dana I added a hinging joint on the upper shrouds, and the same height as the mast pivot point. These pivot points were each separately secured forward with low stretch line. The secured shrouds prevented side to side movement (or restricted it at least). Then line over gin pole (with also required restraining lines to the sides) with block and tackle and could raise and lower mast on our own Your Mariah mast is going to be heavier of course, but same approach should work. Sorry, this is very difficult to describe in words.

One point: If the boat is in the water when you raise the mast, be aware that side loads can get very high when raising mast. As mast is being raised if mast swings a bit to one side or the other, the boat will as a result roll a bit to that side, which then increases the swing of the mast even further to the side, which of course rolls boat even further... Do not underestimate the potential for things to go wrong.

[mf70]

I have watched several DIY'ers raise masts. Some worked, and some did not. If you are not used to they way rigging can behave, get help, and listen to your informant!

Gravity is VERY non-negotiable.

Bruce Bingham is an important resource. I would love to see his drawings. I currently use an A-frame for my keel-stepped rotating masts, and they demand an entirely different series of "attention points" than my earlier gin-pole rig.

A sketch of the pivot systme similar to what I used is at:

mast electric wiring

[pollyvon]

Thanks folks for your opinions. I'll check out the book.