How Long Is a V222 mast? What length to make a gin pole?

DrJudyB · Jun 14, 2018

Todd Atchison said:
...I do have some deck eyes directly outboard of the mast's turnbuckle:

View attachment 152074

I could easily slip a hook from a rachet strap through that. I'll keep you guys updated. Plan on trying again this weekend after the repairs.

I assume you meant to write that the strap eyes are Outboard of the mast tabernacle (not mast turnbuckle”)

There are two problems with using those eye for anchoring the baby stays. First, they aren’t tall enough to be on the same axis as the pivot bolt in the mast. They appear to be at least an inch lower than the bolt hole in the bottom of the mast. If the baby stays are snug enough to prevent sway when the mast is down, they will be too tight when the mast is up.

Secondly, the eyes are attached with a wood screw into the deck. That’s fine for resisting a shear force (perpendicular to the axis of the fastener), but not a vertical force. The fasteners for the anchor point for the baby stays should be through bolted, with fender washers on the backside to resist a tensile load pulling up and parallel to the fastener.

I’d recommend that you install some small u bolts or beefy strap eyes in line with the hole through the mast, horizontally and verticallly.

Personally, I’d use wire cables for the lateral bridles, it stretches less. Straps and rope are very stretchy. Dyneema has a lot of initial construction stretch. It gets fluffy (loosely braided) every time you disconnect it from a load and that makes it noticeably too short at first and too loose after it’s loaded for a few seconds.

I’d also recommend putting some turnbuckles in the wire baby stays. That makes it easy to fine tune the length of the baby stays so you can get the length right once and keep that length.

Judy

DrJudyB · Jun 14, 2018

Here's a picture of how we lined up the anchor points for the mast raising wires with the hinge on our mast base.

Timethief · Jun 14, 2018

It could be me, but isn't that just a tad bit overkill for a 22' Mac?

DrJudyB · Jun 14, 2018

Timethief said:
It could be me, but isn't that just a tad bit overkill for a 22' Mac?

@Timethief : I don’t think my recommendations to Todd are “overkill”.

post #23 was about alignment, not hardware. See post #22 for my recommendations on hardware selection. I recommended that Todd use eyestraps or ubolts to anchor the wires, and to through-bolt them with fender washers for backing.

Judy Blumhorst

walt · Jun 14, 2018

They appear to be at least an inch lower than the bolt hole in the bottom of the mast. If the baby stays are snug enough to prevent sway when the mast is down, they will be too tight when the mast is up.

Great point! I think someone figured out a slightly different way to deal with the issue above that does not involve raising the eye strap to the same axis that the mast pivots by moving the eye straps slightly forward. My 26S came this way and its worked fine.

If the eye strap is exactly lined up with the mast pivot hole from side to side but its lower than the mast pivot hole because of deck shape, the stays will tighten as the mast is raised.

But if the eye strap is moved forward of the mast pivot, the stays would tend to loosen as the mast is raised.

So someone (maybe from the factory.. I dont know) found a compromise spot with the eye strap a little forward of the mast pivot. As the mast goes up, one mechanism is trying to tighten the stay, another mechanism is trying to loosen the stay. I say someone as I dont know who placed my eye straps but it works fairly well. My "baby stays" are snug when the mast is down but then slightly loosen up as the mast is raised. The mast will angle off to one side a little as its going up but at about 3/4 way up, the mast sailing stays begin to center the mast. The baby stays never get too tight. I measured how far forward the baby stays are of the mast pivot for someone not too long ago and its in the first picture. On the 26S, the stays are placed close to 3.5 inches FORWARD of the mast base rotation axis. Once again, I dont know if the factory or a PO installed the eye straps but I have never felt any urge to move or change them.

I had also checked the eye straps for backing plates since I had not installed them. Whomever installed them did use some sort of backing plates and bolts/ lock nuts.

Timethief · Jun 14, 2018

Apologies - I was just looking at that picture and thinking the plating and U-bolts were more than raising a mast really needed. I also don't really think the alignment needs to be that precise - with regards to the eye straps being an inch or more below the height of the mast bolt hole or the dyneema stretch (yep, tied it all tight, stretched it the inch or so it stretched, and that gave me the slack I needed to clip the line to the eyes) - but that's just from me playing with my boat for the past few months, raising and lowering the mast by myself. Everyone has an idea what is best, and I am always looking for ways to improve my rig.

DrJudyB · Jun 14, 2018

walt said:
...

So someone (maybe from the factory.. I dont know) found a compromise spot with the eye strap a little forward of the mast pivot. As the mast goes up, one mechanism is trying to tighten the stay, another mechanism is trying to loosen the stay. I say someone as I dont know who placed my eye straps but it works fairly well. My "baby stays" are snug when the mast is down but then slightly loosen up as the mast is raised. The mast will angle off to one side a little as its going up but at about 3/4 way up, the mast sailing stays begin to center the mast. The baby stays never get too tight. I measured how far forward the baby stays are of the mast pivot for someone not too long ago and its in the first picture. On the 26S, the stays are placed close to 3.5 inches FORWARD of the mast base rotation axis. Once again, I dont know if the factory or a PO installed the eye straps but I have never felt any urge to move or change them...

That's clever! I like it!

But the geometry/trigonometry is complicated to solve on paper... and I bet it would take a lot of trial and error to get the right spot on a variety of boats.

Lining up the pivots using a rod through the mast pivot point is easy to do on any boat. Poke a rod through the hole in the mast hinge and take a measurement of how high you need to make the hole to attach the "baby stay". Install a block of plastic or wood under the ubolt or eye strap to get the pivot point at the right height and then through bolt it in the right place outboard of the mast pivot. Easy-peasy.

Sumner · Jun 14, 2018

walt said:
....So someone (maybe from the factory.. I don't know) found a compromise spot with the eye strap a little forward of the mast pivot. ....

Our S has the same setup and it works fine ...

http://purplesagetradingpost.com/sumner/macgregor/rigging-2.html

... the factory or someone else had set it up that way before we bought the boat,

Sumner
===================================================================================
1300 miles to The Bahamas and Back in the Mac...
Endeavour 37 Mods...
MacGregor 26-S Mods...http://purplesagetradingpost.com/sumner/endeavour-main/endeavour-index.html
Mac Trips to Utah, Idaho, Wyoming, Canada, Florida, Bahamas

timebandit · Jun 16, 2018

My pad eyes are mounted 21 1/2 inches outboard and on center line of the mast backed by fender washer. I have horned cleats on both sides of the mast at six feet.
The baby stays for raising the mast are cam buckle type MOTORCYCLE TIE DOWNS that are made of thick 1 inch polyester webbing with a working load of 400# and breaking load 1200#.
I use my jib boom for a pole and it is about 9 feet long, One end is connected to a fitting on the deck just in front of the mast step. The other end is connect to the mast with the jib halyard and the other to the deck with block and tackle which is my main mid boom sheeting. If you need more power you can always take the tail of the block and tackle and run it through the cam cleat and to the winch, Works good if something hangs up.
I set the gin pole about 10 degrees off vertical so that when the block and tackle is bottom out the mast is almost vertical; just place your knee on the pole to attach the fore stay.
When all is done the baby stays come off and stuffed in a bag, the jib halyard is connected to the jib, the block and tackle is is disconnected and put back on the main boom and the jib boom is hung on the opposite lifeline from the jib out of the way until needed.
Space taken up on the boat-----less that a 1/2 gal. milk carton.

Tedd · Jul 1, 2018

Todd Atchison said:
What length do I need to make my gin pole for maximum mechanical advantage?

Mechanical advantage increases with the length of the gin pole so, within reason, longer is better. I just made a new mast raising system for my Mac 26S and the gin pole is just shy of ten feet long. I use that length because I pull the mast up by the forestay and with the right length of gin pole it pulls the forestay turnbuckle right down to the deck fitting. Makes raising the mast really simple. The gin pole has two legs and attaches to the outside of the mast deck plate on both sides, for stability.

Tedd · Jul 1, 2018

Todd Atchison said:
Or does one adjust the tension manually as the mast goes up?

What I did was fabricate the baby stay attachment points on the hull so that they are in line with the pivot axis of the mast. That way the tension stays constant as the mast rotates. When I did my first trial run I hadn't made the actual baby stays yet so I tried using the rope temporarily. It was way too stretchy. So I did my usual thing of over killing it in the opposite direction and I made baby stays out of lightweight chain. They worked so well I'm still using them.

One nice thing about the chain baby stays is that, because the attach point on the mast is free to rotate, I can adjust the tension in the stays by simply rotating the mast attach point. The chain winds up and shortens. I pre-twist the stays so that they un-tension slighty as the mast goes up.

richrsd14 · Jun 14, 2020

I just installed a very beefy Ballinger hinged step on my 1971 Ranger 26 (Mull) & the side-swinging mast issue comes up all the time with others who have tried self-stepping. But Good Old Boat has a great article addressing this very issue with an very elegant solution using 2 simple bridles.

No Fear Mast Stepping! | Good Old Boat

goodoldboat.com

The crucial thing, they say, is to make a single pivot point for the bridles from a single ring on each side to all stays AND to line up that pivot point as much as possible along the same axis as the mast step hinge pin (i.e., you should be able to run a rod through both rings & the step hinge). That way the stays don't tight or loosen as the mast goes up. I have not yet rigged it, but will this week.

My mast is about 33' & fairly heavy (per that era), maybe 200 lbs. I'm going to try to use my spinnaker pole as the gin pole b/c it already has a track that will put the pole about 2' from the bottom of the mast. I'm thinking that's probably close enough to the bottom in terms of leverage & it makes attaching the gin pole literally a snap. My J measurement (12') is longer than my spinnaker pole, & they say the pole should be close to the J length but I'm going to give it a try with what I have anyway. The boom is longer than the spinnaker pole, but not as easy to attach to the fore side of the mast as the spinnaker pole. That's my back up plan.

If the bridles solve the side swing problem, then in theory the mast can be stepped single handedly.

Best,
Rich