Finally REALLY sailed my boat

[Hermit Scott]

it depends, what line is that and do you have a wider photo to show the overall setup.

It is the forward most bail on the main sheet traveller.
I took the boom apart, powder coated it and installed new hardware, but into the same holes for the bails. It is a 1979, I guess they didn't start through bolting them then. Some C30 booms have the outhaul inside so I don't know what set up they would have to attach the bails. This pic shows it. The way the holes were positioned there wasn't any other way to put the bails back on the boom. The middle bail is straight, the outside are angled and the bolt pattern is not reversible.
You know how people with sailboats say it's the journey not just the destination, working on the boat and sailing the boat are sort of the same thing to me.

 

[Todd Smith]

In that second pic, does that bail look to be facing the wrong way? To the left is toward the bow.

It doesn't matter what line it is, the pull from the block should line up with the bail, so there is no torque on the bail. It looks like someone changed the lead of the main sheet at some point, but did not change the bail.

 

[sailingdog]

First, it is the forward most bail on the boom for the main sheet. The mainsheet traveler is the track going atwarthships on the cabin top.

Second, the reason it looks funny is because you have the mainsheet reeved incorrectly. The mainsheet is supposed to go from that block back to the mainsheet car... not forward to the base of the mast.

The reason the forward one points aft, the mid one points down and the aft one points forward is that all three are supposed to go back to the mainsheet traveler car, as seen above.

 

[Hermit Scott]

First, it is the forward most bail on the boom for the main sheet. The mainsheet traveler is the track going atwarthships on the cabin top.

Second, the reason it looks funny is because you have the mainsheet reeved incorrectly. The mainsheet is supposed to go from that block back to the mainsheet car... not forward to the base of the mast.

The reason the forward one points aft, the mid one points down and the aft one points forward is that all three are supposed to go back to the mainsheet traveler car, as seen above.

To rig it like your drawing, I would need a tripleblock on the traveler. I think it is called a fiddle block, From top to bottom on the block, it has (top)a pin to hold the splice, (middle)a small sheave, and (at the bottom) a larger sheave. Then under that has the shackle to attach to the traveller.
Everything looks original. Eventually I will get around to replacing this gear. I want the traveller raised up about 2 feet though on a stainless bow, so I can see under it instead of over it. I may have to rearrange the block configuration to account for the change in loads.

 

[Scott T-Bird]

Sailingdog's diagram seems correct ...

Scott, you should have a triple block with a becket (the pin for the spliced end). If you have a fiddle block, that seems like the wrong piece of equipment for this application because there would only be 2 sheaves and you are losing the mechanical advantage of the intended 6 to 1 system. Besides, the fiddle block has a much taller profile, which isn't really useful or wanted in this application. The triple block has a better profile.

Is the working end of the sheet going forward to the mast and then back to the cockpit via a deck organizer? That doesn't seem very efficient ... there would be multiple unnecessary turns with all that friction loss. I guess I don't understand the layout. From a triple block mounted to a traveler car, you should have one minor turn to a clutch or cleat at most.

 

[sailingdog]

Your boat, because of the mid-boom sheeting really should have a triple block with becket on the mainsheet traveler car. That would give you a 6:1 mainsheet purchase. I doubt that the fiddle block is original given the three bails on the boom. A fiddle block would only require TWO bails...not three.

To rig it like your drawing, I would need a tripleblock on the traveler. I think it is called a fiddle block, From top to bottom on the block, it has (top)a pin to hold the splice, (middle)a small sheave, and (at the bottom) a larger sheave. Then under that has the shackle to attach to the traveller.
Everything looks original. Eventually I will get around to replacing this gear. I want the traveller raised up about 2 feet though on a stainless bow, so I can see under it instead of over it. I may have to rearrange the block configuration to account for the change in loads.

 

[Stu Jackson]

Congratulations.

Do you need those jib fairlead blocks?

 

[Hermit Scott]

From my count, the arrangement I have is 6:1. Adding a triple block would not increase that either. It would make the routing simpler but not more purchase.

 

[Hermit Scott]

Congratulations.

Do you need those jib fairlead blocks?

I did measure them when I was down this time. I meant to PM you when I got back last night, but a friend stopped by and we drank wine and played games until 5 am. Totally worth it though.
The tracks I have are 1", but those cabin top tracks are pretty much useless with the 150. Thank you so much though for the offer. The springs I added to the cars I have really worked flawlessly so I guess I am done messing with those.

 

[Joe]

I'll chime in here and comment on raising the traveller track too high.... No... don't do it. You will not gain any visibility and it may change the mechanical effeciency of the mainsheet tackle.

As far as the diagram... well... that's not the way Catalina set it up originally. I'll leave it to you to check the owner's manual... here's a link.. http://www.catalina30.com/TechLib/PartsManual/Rigging.pdf see page 8. The catalina version does, in fact, use a fiddle block. It also shows the sheet running forward to the mast, then back to the cockpit.

 

[Hermit Scott]

I'll chime in here and comment on raising the traveller track too high.... No... don't do it. You will not gain any visibility and it may change the mechanical effeciency of the mainsheet tackle.

As far as the diagram... well... that's not the way Catalina set it up originally. I'll leave it to you to check the owner's manual... here's a link.. http://www.catalina30.com/TechLib/PartsManual/Rigging.pdf see page 8. The catalina version does, in fact, use a fiddle block. It also shows the sheet running forward to the mast, then back to the cockpit.

Thanks for that post Joe. Stu directed me to that exact page. I used it when buying lines and when I rigged my mainsheet but I forgot that I used that exact page. I am missing the block that is at the goose neck. But in my opinion it does not affect the functionality, and is better if I am using a vang, which is not shown in that particular diagram.
I see in that diagram that Catalina did design the bail in question to have torque on those fastners. That is a design flaw. I guess they solved this later by having rotating bails, so they would self align. This bail should be splitting the angle of the sheet as it goes in and comes out of the sheave. However, it lasted 30 years with out a problem, so I won't change it.
The sheet does run to the mast andd then to a cabin top winch.

 

[sailingdog]

From my count, the arrangement I have is 6:1. Adding a triple block would not increase that either. It would make the routing simpler but not more purchase.

Sorry, but your boat is setup with a 5:1 purchase, not a 6:1. To get a 6:1 purchase, the line has to start on the static side of the tackle. Yours starts at the boom...

A simple way to figure out the purchase is to count the lines connecting the static and moving sides of the purchase. You have five lines connecting the boom to the deck—the drawing I posted has SIX—so going to a triple block would give you 20% more leverage, and allow the lines to lead fair without loading the bails in a direction they're not designed for. The boom was clearly setup for a traditional 6:1 mainsheet, regardless of what the Catalina documentation says, otherwise the person who setup the bails is a complete idiot.

 

[Ctskip]

Congratulations. It's always a good thing when the admiral smiles. Chafing is the easy part.

Keep it up,
Ctskip

 

[Hermit Scott]

Saildog-I think that the mainseet I have and the one in your drawing are mechanically identical. They are both 5:1 right? I think they are both double luff tackle rove to disadvantage. I got out my college mechanism design book, but actually found a clearer reference online about getting your captains license. http://books.google.com/books?id=wz...6AEwCA#v=onepage&q=double luff tackle&f=false
The line does start on the traveller, but I think it is 5:1??

 

[All U Get]

Touche'

Saildog-I think that the mainseet I have and the one in your drawing are mechanically identical. They are both 5:1 right? I think they are both double luff tackle rove to disadvantage. I got out my college mechanism design book, but actually found a clearer reference online about getting your captains license. http://books.google.com/books?id=wz...6AEwCA#v=onepage&q=double luff tackle&f=false
The line does start on the traveller, but I think it is 5:1??

Hi guys,
I've got mine running like the Catalina bible and it rubs along the vang. The vang always has a twist under load so the 6:1 from the main isn't perfect. To compensate I grab the end ofthe boom and haul in and down so that my wife thinks she's really pulling in the main. It's all about salesmanship.
All U Get

 

[sailingdog]

No, yours only has five lines connected to the moving part... that means it gives a 5:1 MA... the setup I drew has SIX lines connected the moving part (boom), which gives it a 6:1 advantage. Yours is a double luff tackle, mine is a three-fold purchase..

To further explain... here is a drawing, with six different block and tackle setups. Going from the top left to the top right, then the bottom left to the bottom right, they are 1:1; 2:1; 3:1; 4:1; 5:1 and 6:1, assuming that the bottom block is affixed to the deck, and the top blocks are attached to the boom.

The upper left drawing is clearly a 1:1... the next one is clearly a 2:1... the upper right drawing is clearly a 3:1. The thing that is confusing people is the fact that the mainsheet HS has doesn't lead the last bit of line back to the mainsheet traveler, but that doesn't change it from being a 5:1. The block at the base of the mast is merely changing the direction of the line, not contributing to the mechanical advantage.

To analyze a block and tackle, you have to look at the number of lines going to the MOVING portion of the tackle—which on a sailboat mainsheet setup is the boom side, not the mainsheet traveller side.

Now, do you see how yours is only a 5:1 and mine is a 6:1

Saildog-I think that the mainseet I have and the one in your drawing are mechanically identical. They are both 5:1 right? I think they are both double luff tackle rove to disadvantage. I got out my college mechanism design book, but actually found a clearer reference online about getting your captains license. http://books.google.com/books?id=wz...6AEwCA#v=onepage&q=double luff tackle&f=false
The line does start on the traveller, but I think it is 5:1??

 

[kloudie1]

Okaayyyy.. Here is the deal on Scott's mainsheet.. The thing has 6 lines attached to the boom but one is not close to perpendicular to the boom load.. so what ya really have there is a 5.5 or 5.something purchase because the tension in the piece going to the boom base will not contribute a full pull.. the pull resulting from that last line will be decreased by the sine of the angle between the boom and the sheet part heading to the boom base. So ya get a pretty good pull from the first 5 then the last one might be something like 0.867 if the angle is something like 60 degrees..If you were to move the block under the gooseneck aft, until it was very close to the other blocks on deck, that force would increase until it would be the same as the other pulls and you'd have a 6:1 (nominal)

 

[sailingdog]

WRONG... he only has five lines going to the moving part of the block and tackle...the boom... that means at most it will be a FIVE to ONE.

Look at the drawing in my previous post... that should make it very apparent... you can not have a six-to-one tackle if the line starts on the boom and the terminal end is on the deck.

Okaayyyy.. Here is the deal on Scott's mainsheet.. The thing has 6 lines attached to the boom but one is not close to perpendicular to the boom load.. so what ya really have there is a 5.5 or 5.something purchase because the tension in the piece going to the boom base will not contribute a full pull.. the pull resulting from that last line will be decreased by the sine of the angle between the boom and the sheet part heading to the boom base. So ya get a pretty good pull from the first 5 then the last one might be something like 0.867 if the angle is something like 60 degrees..If you were to move the block under the gooseneck aft, until it was very close to the other blocks on deck, that force would increase until it would be the same as the other pulls and you'd have a 6:1 (nominal)

 

[Hermit Scott]

Okaayyyy.. Here is the deal on Scott's mainsheet.. The thing has 6 lines attached to the boom but one is not close to perpendicular to the boom load.. so what ya really have there is a 5.5 or 5.something purchase because the tension in the piece going to the boom base will not contribute a full pull.. the pull resulting from that last line will be decreased by the sine of the angle between the boom and the sheet part heading to the boom base. So ya get a pretty good pull from the first 5 then the last one might be something like 0.867 if the angle is something like 60 degrees..If you were to move the block under the gooseneck aft, until it was very close to the other blocks on deck, that force would increase until it would be the same as the other pulls and you'd have a 6:1 (nominal)

We are just trying to determine the mechanical advatage before taking things into consideration like line angle or (static and dynamic)friction in the sheaves. With out figuring out the theoretical advantage it is impossible to refine the results and add in all the real world corrections.
To resolve all the forces of the sail and the moment about the goose neck for the three bails at different distances is a small statics and dynamics exam in and of it's self. But no real practical info is to be gained.
Apparently to get your captains license you have to know this stuff.

So if where the line exits the foremost bail if it went straight down or back to the traveller(for simplicity's sake) it would add purchase. IF it is rigged like the catalina specs it takes away purchase? Mine being at a 45 degree angle should add some purchase and the angle is too much to neglect.

 

[sailingdog]

The angle of the line does affect the mechanical advantage to some degree, but isn't really a factor in this case. The way the boat is rigged in the photo is a 5:1 mechanical advantage, not 6:1. Look at the image I posted two of my posts back.... that clearly shows what I'm talking about.

We are just trying to determine the mechanical advatage before taking things into consideration like line angle or (static and dynamic)friction in the sheaves. With out figuring out the theoretical advantage it is impossible to refine the results and add in all the real world corrections.
To resolve all the forces of the sail and the moment about the goose neck for the three bails at different distances is a small statics and dynamics exam in and of it's self. But no real practical info is to be gained.
Apparently to get your captains license you have to know this stuff.

So if where the line exits the foremost bail if it went straight down or back to the traveller(for simplicity's sake) it would add purchase. IF it is rigged like the catalina specs it takes away purchase? Mine being at a 45 degree angle should add some purchase and the angle is too much to neglect.