Single line reefing

ISIS

.
Apr 27, 2011
18
ISIS 42'MKII Toronto NSW Australia
does anyone know how the reefing lines are set up on MK I I 42 .Catalina. As far as I can see there is a block in the boom.Has anyone tried to change the system to a single line for both reefs without the block in the boom ? Thanks in advance.
Note Isis is the name of my boat after the Egyption Godess .no connection to the rats in the news .
 
Feb 2, 2006
464
Hunter Legend 35 Kingston
Different boat and such, but I tried to run my Legend 35 with a single line system for both the tack and clew, without the double block in the boom, and there was so much friction that I abandoned it after one season. The problem with the friction was that it starts at the tack and prevented the clew from getting tight enough without over tensioning the tack.

I switched to using the reefing lines only for the clew only, and using a simple double horn arrangement at the gooseneck/tack to manually hook on the new tack cringles. The halyard controls the luff tension, and the reefing line controls the clew. I can reef faster too. Someone does have to go forward to the mast though.

The systems with the two blocks inside the boom would seem like they reduce the friction in the appropriate way so that the load is transfered to the clew once the tack is tensioned without having to draw the line through the tack cringle. Installing reefing "blocks" on the sail would further reduce friction. For me, I've got outhaul blocks in my boom that would prevent using such a system.

Just my 2 cents.

Cheers
Chris
 
Jul 14, 2015
840
Catalina 30 Stillhouse Hollow Marina
Different boat and such, but I tried to run my Legend 35 with a single line system for both the tack and clew, without the double block in the boom, and there was so much friction that I abandoned it after one season. The problem with the friction was that it starts at the tack and prevented the clew from getting tight enough without over tensioning the tack.

I switched to using the reefing lines only for the clew only, and using a simple double horn arrangement at the gooseneck/tack to manually hook on the new tack cringles. The halyard controls the luff tension, and the reefing line controls the clew. I can reef faster too. Someone does have to go forward to the mast though.

The systems with the two blocks inside the boom would seem like they reduce the friction in the appropriate way so that the load is transfered to the clew once the tack is tensioned without having to draw the line through the tack cringle. Installing reefing "blocks" on the sail would further reduce friction. For me, I've got outhaul blocks in my boom that would prevent using such a system.

Just my 2 cents.

Cheers
Chris
I use single line run back to the cockpit, but add an outhaul also to the clew to prevent above problem. I do not have to leave the cockpit to reef.
 
Jul 14, 2015
840
Catalina 30 Stillhouse Hollow Marina
Do you mean you have two lines for each reef?
One line for the reef to both luff and leach lead back to cockpit. One line for the outhaul only. Could also switch outhaul to reefed point, but I like to have it all hooked up ahead of time.
 
Jan 19, 2010
1,169
Catalina 34 Casco Bay
Hope this helps or at least provides a direction of travel. I've converted my last 3 boats to single line slab reefing that lead direct to the cockpit. As I may be single handed from time to time, I need to be able to reef by myself. Since most boats come with a 2 point reef system, I have always gone with the 2nd point.

The quick and the dirty is that I make fast the bitter end of the reef line to the boom directly under the 2nd leech cringle. That line runs up thru and returns to the boom and turns forward thru a cheek block. At the gooseneck, a 2nd cheek block directs the line up the the luff cringle, thru it and down to a block at the mast base. From here it is directed to the cockpit via a flat block on the cabin top. I usually secure it with a locking cam cleat. When used in conjunction with the Tides System, I can reef in less than a minute by myself. Reference marks on the main halyard and reef line facilitate the quick reef.

Rick
 
Nov 14, 2013
200
Catalina 50 Seattle
I've got a C50 with an Isomat boom and rigged the first reef using their butterfly block design. It works far better than any other single line system I've used. That said, I'm not sure how practical it is to rig a second reef that way. There's not a lot of room in the boom and I would worry about the two butterfly blocks and associated lines getting tangled.
 
Feb 2, 2006
464
Hunter Legend 35 Kingston
I believe that selden booms are designed to work with special shuttle blocks so that each block set faces differently (one has blocks to port and the other to starboard) so that when they pass, they don't interfere. The Isomat shuttle block are just sort of designed to be "snag free", and will likely not catch each other. Obviously it critical that none of the reefing lines cross each other.

 
Nov 14, 2013
200
Catalina 50 Seattle
I used a Harken deck organizer as a boom shuttle and it works well. I don't think the issue is with the shuttles themselves, just all the spaghetti in there. I'd be concerned about the tangle factor and would want to practice reefing with that setup many tens of times before I'd trust it. When you need to reef is not the time to have to troubleshoot that sort of thing.
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
I believe that selden booms are designed to work with special shuttle blocks so that each block set faces differently (one has blocks to port and the other to starboard) so that when they pass, they don't interfere. The Isomat shuttle block are just sort of designed to be "snag free", and will likely not catch each other. Obviously it critical that none of the reefing lines cross each other.

I know this is an old post, but I am trying to restore the single line reefing system on my new (to me) 1996 Tartan 3800, and this is the exact same drawing that Tartan supplied! (with the "Isomat AutoReef System" label repaced with "Tartan 3800"). Thanks! Good clue for me. I might need to find those shuttle blocks.
 
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Dec 2, 2017
9
Pearson 31-2 Milwaukee
FYI rigrite is out of the isomate internal shuttle blocks... I need a replacement and a spare but cant find one. If anyone finds a suitable replacement (especially with ballbearings) please let us know. I live in Wisconsin and have visited Harken HQ and they do not have something that will work..... Back to the drawing board.
 

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
FYI rigrite is out of the isomate internal shuttle blocks... I need a replacement and a spare but cant find one. If anyone finds a suitable replacement (especially with ballbearings) please let us know. I live in Wisconsin and have visited Harken HQ and they do not have something that will work..... Back to the drawing board.
I restored single line reefing to my boat, which required finding two shuttle blocks.

I found two 42mm (sheave diameter) shuttle blocks made by Sea Sure, available for sale from Sea Screw, Ltd., in the UK I got the last two they had. They currently have two left of the 28mm size.

The are nicely made, with "densely packed carbon fibre needle roller" bearings. Thy have rubber-like material housings so they won't make a lot of noise inside booms.



Here's a Sea Sure catalog. Search for 09-60 and 29-60.
http://www.teufelberger.se/wp-content/uploads/pdf/SeaSure.pdf

I found Sea Screw to be very reliable, with very quick shipping, even though they are in the UK. They gave me a big discount for buying the last two, and I didn't ask for it.

Here's Sea Screw's website page with the remaining blocks:
https://www.seascrew.com/browse.cfm?s=Block Inside Boom Single line Reefing

The Sea Sure blocks may be available elsewhere, I don't know.

I'm very happy with how these worked out. I can very easily reef from the cockpit with a single line. I have the option of putting the reefing line on a winch, but haven't found it necessary yet.

Good luck.

Update: these guys seem to have both sizes:
http://www.seapost.co.uk/seasure-09-60-inside-boom-single-line-reefing-block-12705-p.asp
 
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