Jib Sheet Turning Block-Rail Mounted ????

Stu Jackson · Apr 7, 2015

I've read this a few times and still don't understand it.

What "rail?"

Are you actually looking for a cheek block that turns the jib sheet from a position AFT of the winch?

Like this?

http://www.westmarine.com/buy/schaefer--stainless-steel-cheek-block-aluminum-sheave--6724918

This is a smaller one than we have on our C34, which are Garhauer BIG cheek blocks, just posted this link to show you the concept.

jimmcgee · Apr 7, 2015

Tom,
I'm not exactly sure what you're asking but I think these pics may answer your question.

In the top photo you can see the jib sheet run to a block on the jib car and then back to a deck mounted turning block aft of the winch.

The second photo is a close up of the turning block. All the hardware is Garhauer and stock on our '95 MKIII. I'd be leery of mounting the turning block on a stanchion. There's a lot of load on the jib sheet when the wind is up.

Does that help?

Jim

Stu Jackson · Apr 7, 2015

caltom said:
The "Rail" is the 1" aluminum rail that runs down both sides of the deck. The Jib Sheet Lead Blocks are mounted on it.

Yes I want to turn the Jib Sheet from a position aft of the winch.

Mounting a cheek block like the one you linked to are what the sail maker suggested.

What you are calling a "rail" is actually called a "track" and cheek blocks aren't mounted on the track but rather like jim's picture. If you have an older boat, then they are placed on the outside of the coaming, almost vertical.

Jim's picture shows the appropriate size, made by Garhauer. Mine are mounted on 1 or 1 1/2" thick wood spacer blocks to make a fair lead to the winch without rubbing on the fiberglass of the coaming.

Anonymous 121765 · Apr 8, 2015

Cal,

Do it the way Jim's pics show it. That's the correct mount.

That turning block will carry the greatest load from your sail. Those flimsy stanchions are not for stressing. That's why I refer to them as, "Lose your life lines."

Make sure you mount a good backing plate below & caulk well.

CR

Hogheaven · Apr 8, 2015

hmm yes yes, I have noticed that my jib sheets come in contact with the side of the cabin and or coaming depending on how they are adjusted.

for folks that dont know my 87 MKII has an additional track running aft along the cockpit, in addition to the track alongside the cabin. I see this was added/deleted over the years, by the factory, when viewing other models of 30's.

I think this is in order for me also to avoid the added friction of the jib sheets in contact with the boat. I have flat turning block way aft behind the aft track track for flying the spinnaker, but that sail is new to me so what do I know!

My wife and I joined an active club in November DCYC.ORG and have been racing PHRF with an active group of J24's. I wonder how quickly tacking is accomplished with the additional turn aft of of the winch with the springy/holdy/turning blocky thingy. Enquirering minds want to know! I will post back after Saturdays regatta as I took them off of my Mac which is waiting to be sold.

Regards,
Nels

Stu Jackson · Apr 8, 2015

Hogheaven said:
1 for folks that dont know my 87 MKII has an additional track running aft along the cockpit, in addition to the track alongside the cabin. I see this was added/deleted over the years, by the factory, when viewing other models of 30's.

2 I think this is in order for me also to avoid the added friction of the jib sheets in contact with the boat. I have flat turning block way aft behind the aft track track for flying the spinnaker, but that sail is new to me so what do I know!

3 I wonder how quickly tacking is accomplished with the additional turn aft of of the winch with the springy/holdy/turning blocky thingy.

1. Outer tracks have always been an option for the original owner.

2. Nope. It is a turning block, simple. Some folks like them, others feel it adds too much friction.

3. Doesn't make any difference. Same line, right?

Stu Jackson · Apr 8, 2015

As long as the lead is fair, should work. That picture sure helped. Good luck.

woodster · Apr 8, 2015

caltom said:
First off, I appreciate the input and apologize if my question was confusing.

Yes I want to turn the sheet aft of the winch. A deck mounted block is an option. What I'm thinking about is attaching a turning block to the T Track that runs along the rail as seen in the red circle. The other photos are of the pieces I would use.

At 20 knots the load on the sheet would be about 450 lbs. At the turning block it would be about 900 lbs. The SWL of the slide is 2400 lbs and for the block it's 2800 lbs.

This all seems like it should work.

Is there something I'm over looking?

correct me if i am wrong here but the load at the turning block would still be 450 it is a 1 to 1 through the block

woodster · Apr 8, 2015

caltom said:
Fundamental Concept 3: Pulleys are force magnifiers! When the two weighted legs of the
rope passing through a pulley are maintained in a parallel configuration, the forces brought to bear on the pulley’s point of attachment are doubled!

ops i stand corrected lol that is at the attaching point yes

jimmcgee · Apr 8, 2015

Stu Jackson said:
1. Outer tracks have always been an option for the original owner.

Hmm, I didn't know that. I've wondered if the deck would support an outer track mounted outside the stanchions...

Thanks for posting Stu.

dj2210 · Apr 8, 2015

Here a picture on my 1990 with the turning block as mounted from the factory. Hope it helps.

jonelli · Apr 8, 2015

Here's my turning block aft of the winch... I thought it was stock?
My Jib sheet track is on the complete inside of the safety rail, not like yours at all... I dont' have a pic that shows it...

My Jib sheet track is on the complete inside of the safety rail, not like yours at all...

jonelli · Apr 8, 2015

Hah. Didn't realize this thread was you! If your jib track goes that far back, why not? Mine doesn't.
And I was just there a few minutes ago grabbing my batteries to replace. Lol

Stu Jackson · Apr 8, 2015

caltom said:
Thanks Jonelli. Your turning block is mounted in a fairly typical location. Which is maybe what I should do.

My thinking is if the rail will take the load why not use it. That way I don't need to add holes to the deck. I can also leave the jib sheet threaded through the block and just slide it forward so it's out of the way for boarding.

Tom,

I guess if "you're workin' on the railroad" the difference between a rail and a track may not make much difference, although purists would take umbrage at the differences between a switch and a turnout.

It really is a track on a sailboat.

Maybe since you have one on each side and you looked down from the mast head you could consider them rails...:neutral::neutral::neutral::neutral:

With your outboard tracks your idea will work just fine.

If you chose to install a cheek block, then I'd still recommend doing it vertically to avoid the line rubbing against the cheek of the block, which it could do on the top of Tom's block location.

Good luck.

Jib Sheet Turning Block-Rail Mounted ????

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