Whats in the boom?

[SeaRogue]

I am replacing all the standing and running rigging on Moonshine. It previously had a roller furling system on the main. I have removed that and I am now returning it to its orignal configuration, if I can figure out what that was.

It seems that there are three systems within the boom. A topping lift, an outhaul, and what appears to be a reefing line for the aft end of the boom.

There is a bolt that goes thru the mast near the forward end. That bolt seems to anchor a block for the outhaul system. Rope attaches to the block anchored to the line and goes aft to go around a block then forward again and out the front of the boom. The aft block is attached to a wire cable that exits the boom on top, goes around a sheave and forward to attach to the clew of the main. I think I understand that part.

Another line attaches in some way to the same bolt that goes all the way thru the boom. I think that is a part of the topping lift system, but I can't figure out how that works and how it connects to the bolt and other fittings or blocks within the boom.

The line that seems to be a part of a reefing system is also a bit of a mystery. Its design is simple enough, it anchors on one side of the aft end of the boom, could go forward to a block on the boom track, then up through a reefing gromet, then back down to another block, then aft to enter the boom around a sheave, then forward in the boom until it exits at the front of the boom.

Can someone describe how the topping lift rigging and hardware are fitted?

Do I have the purpose of what seems to be a reefing line understood correctly?

Thanks

 

[mherrcat]

I rebuilt my boom a year ago and took pictures which, unfortunately, have been lost, but I can try to describe what I can recall. (This was on my 30+.)

The outhaul consisted of a single becket block, whose shackle attached to the through-bolt near the gooseneck, and a small fiddle block whose shackle was attached to a piece of 1/8" wire with thimbles on each end. The other end of the wire came out the end of the boom over an aluminum sheave in front of the boom end fitting and connected to a pin through the outhaul car. 5/16" double braid line ran from the becket on the single block to the small sheave of the fiddle block, back to the single block then back to the large sheave of the fiddle block then back forward and out over a sheave in the bottom of the front of the boom to a cleat on the bottom of the boom about 18" back from the front of the boom.

The topping lift consisted of a 5/16" double braid line attached to the through-bolt and led aft to a single block whose shackle attached to a piece of 1/8" wire. The line then came back forward and exited from the starboard side of the boom to a cleat on the side of the boom. The other end of the wire exited the boom through an aluminum sheave in the center of the boom end fitting and then connected to the static topping lift about 1ft or so above the end of the boom. I used a small "quick-link" to connect the boom topping lift wire to the static topping lift wire.

I found the old line and wire that I replaced and here are the measurements. My boom extrusion is 12' 9" not including the end fittings, so the measurements may be a little short for your application:

Topping lift 5/16" line = 13ft (incl. knot/splice for through bolt attachment)
Topping lift wire = 9' 10" (incl. thimbles)
Outhaul 5/16" line = 12ft (incl. knot/splice for becket attachment)
Outhaul wire = 11ft (incl. thimbles)

Don't know about your boom end fittings, but the aft end mine had two delrin sheaves on either side of the topping lift sheave for reefing lines that ran through the boom to two small delrin sheaves on either side of the forward gooseneck end fitting. The forward fitting had two cam locks for the reefing lines which I removed because my reefing lines are led back to the cockpit.

Here is a link to the Kenyon boom fittings on Rig Rite's site. The fittings on my boom are the K-43001A gooseneck and K-11472 outhaul fitting:

http://www.rigrite.com/Spars/Kenyon_Spars/3550-boom.html#3550_Internal_Outhaul_Assemblies

They also list the outhaul tackle on that page, so apparently it can be purchased, but from Rig Rite it will be pricey.

Here is a link showing the exit block K-11110A-1 that sits in front of the boom end fitting for the outhaul:

http://www.rigrite.com/Spars/Kenyon_Spars/Kenyon_Parts/K_exit_block.html

Hope this helps, if not it will certainly get you more confused!

 

[SeaRogue]

Thanks Mark

Mark,

Thanks for that very detailed response. That is exactly the information that I was looking for. It is indeed very helpful.

Tony

 

[Loren Beach]

Within a few years of buying our boat the ss mount for the rod vang broke its weld inside the boom bottom.
I took the boom home and took it apart. Separating the ss screws from the Kenyon alum. fittings was difficult. Once I got the gooseneck off the inside part of the vang fitting was extracted... along with the termination point for the multi-part outhaul.
SS vang fitting reinforced and restored, along with releading the two reefing lines. It's been quite a few years so I only remember that restoring the outhaul tackle was tedious... I believe that a long dowel with some tape on the end to guide it might have been used.

I also took advantage of that opportunity to remove the factory T track from the rear starboard side of the extrusion so I could use a sliding loop system for each reef, which I had grown to like on my prior boat.

Salt air, dissimilar metals, and a lack of any prior maintenance can sure lead to some interesting upgrade and/or repair issues later!


Loren

 

[mherrcat]

Found the internal boom tackle pictures plus the boom end fittings. These make it a little clearer. On the end fitting you can see the reefing sheaves on either side of the topping lift sheave and the outhaul sheave in front. The blocks on the inside of the boom are small; 1.25" to 1.5" dia. max.

On the new lines I replaced the knots with splices. When it is all rigged the fiddle block only ends up about 2ft aft of the through bolt; the block for the topping lift ends up further back so they do not interfere with one another.

 

[mherrcat]

Here is the gooseneck fitting. You can see the handles for cam locks on the reefing lines. I removed these when I refinished the boom.

I did the same as Loren in removing the T-track from the end of the boom. Mine had it on both sides.

 

[Loren Beach]

Mark,
Great pics and commentary. Thank You!

We appear to have the same boom and gooseneck (if not the same model #, they are very similar).

Best,
Loren

ps: I see that you have EZ Jax!

 

[mherrcat]

The blocks I used were Ronstan S40 series. The shackles can be locked so the line doesn't get twisted.

 

[SeaRogue]

Excellent pics

Mark,

Thanks for posting the pics. That is exactly what I have in my boom, although I did not fully understand the topping lift arrangement until I saw your pics.

It seems that the reefing arrangment has been modified by Loren and perhaps others. I would be interested in how the original reefing lines were set up as well as the design and benefits of the "sliding loop system" mentioned by Loren.

 

[Loren Beach]

Until I can learn to Draw...

Mark,
It seems that the reefing arrangment has been modified by Loren and perhaps others. I would be interested in how the original reefing lines were set up as well as the design and benefits of the "sliding loop system" mentioned by Loren.

This sailmaker reefing video popped up with a Google search. While not quite the way I learned, it is very very close. Note that this allows the position of the new clew (for the reef) to be moved back n forth a bit and that this puts the force vector both downward and back, as it needs to.

http://www.youtube.com/watch?v=XbXlEsrlo1s

Lacking pictures or a drawing,

On our boat: (1) the reef line exits the sheave in the Kenyon sheave box at the the end of the boom, (2) goes up to the clew reef cringle, (3) thru it from starboard to port, (4) straight down the sail and around the boom on the starboard side of the extrusion, and under it and brought back up on port side, (5) and then has the end terminated in a small bowline around the part of the line that went up toward the reef cringle. I use a rather slick solid braid for this line.
Reefing - first we lower the sail and get the front/tack floppy ring on the hook and sock up the halyard. Next we slack the main sheet and vang and haul in the reef line, which slides thru the bowline until... the new clew is down on the boom and the reef line is tight.

Last we sheet in and re-set the vang tension as appropriate.

If I have left out something, chalk it up the boat being stripped for winter, tarped over, and poor memory on my part.


Loren

 

[Emerald]

Another good resource is Harken's Tech Corner. Lots of good diagrams and basic information on common setups. For outhauls, we have this:

http://www.harken.com/rigtips/Outhaul.php

which came from here:

http://www.harken.com/rigtips/rigtips.php

which has all sorts of fun stuff to keep you busy for a few hours.