Rigging The New Triple Blocks?

SEMIJim · #1 (**permalink**) 10-17-2007

It just occurred to me: I'm not certain how to rig the new triple blocks for our mainsheet.

The line starts on the bottom block, tied to the Beckett. It's got to end up coming out the bottom block via the center sheave. So, let's say both blocks are oriented with the edges of the sheaves facing you, the the sheaves are ordered 1-3, left-to-right. I would guess it'd go:

Beckett to top sheave #1, to bottom sheave #1, to top sheave #2 (center), to bottom sheave #3, to top sheave #3, to bottom sheave #2 (center), and out through the cleat.

In this way, the sheet crosses over no more than one sheave, max, on any "run." Could as well start at #3 (right), as well as #1 (left).

Jim

k1vsk · #2 (**permalink**) 10-17-2007

Not sure if this particular orientation is there but the Harken catalog which is available online has a number of different configurations; one may apply

KeelHaulin · #3 (**permalink**) 10-17-2007

I think you want a "reeved-right-angle"; the block on the boom will sit 90 deg to the block at the traveler. Hard to describe in words how this is done; look closely at the picture of the 6:1 RRA on the Harken mainsheet page (or compu-spec).

7Psych · #4 (**permalink**) 10-17-2007

Harken makes a block with the beckett to one side...#1545. Be careful of cross sheaving the mainsheet..This may lead to pre-mature wear and the sheet being unable to run free. Have you considered the fiddle block configuraton? All the sheaves are in line as they run in a total verticle pattern. What size boat are you running these on? I had the verticle set up on our Tartan-10 and had plenty of purchase power. If the blocks/sheaves/line are not in alighnment, then the blocks will want to twist. The fiddle block configuration avoids this completly. You can also call Harken..they are VERY helpful! Good Luck.......

SEMIJim · #5 (**permalink**) 10-18-2007

Got it, guys. Thanks. What I was looking for is on Harken's site, just not where one would be likely to find it (IMHO). It's under "Blocks," at the bottom of the page, from a link worded something like "Mechanical advantage to 6:1 and 8:1 systems," or something like that.

7Psych,

Yes, we wanted a 6:1 system so The Admiral could handle the mainsheet under higher loads on her own. The boat is a Pearson 30 which has been converted from end-boom to mid-boom sheeting and the sail plan calls for 198 sq. ft. of mainsail.

Jim

sailaway21 · #6 (**permalink**) 10-18-2007

Properly rigged Jim, they'll end up at the 90 degrees to each other mentioned.

SEMIJim · #7 (**permalink**) 10-18-2007

Quote:

Originally Posted by sailaway21

Properly rigged Jim, they'll end up at the 90 degrees to each other mentioned.

Yup. In fact: As per Harken: The top block is locked to be 90 degrees from the bottom blocks normal orientation. The bottom block is allowed to swivel.

Geez, getting the bottom block attached to the traveler was a PITA with that spring installed.

Jim

sailaway21 · #8 (**permalink**) 10-18-2007

Yeah, and that's alongside the dock! Imagine...

7Psych · #9 (**permalink**) 10-18-2007

Jim.....That purchase will be quite sufficient for your main...my wife would also tend our main on the Ten. Good move to have it comfortable for her...she will be much more inclined to "sail"!

SEMIJim · #10 (**permalink**) 10-18-2007

Quote:

Originally Posted by sailaway21

Yeah, and that's alongside the dock! Imagine...

Of course. Where else would you do it?

Jim