Brion Toss Standing Rigging Design Modifications

Ahoy All,

I was just listening to Sailing in the Mediterranean podcast epsode # 72 ( which is part 2 of an interview with the late Brion Toss. In the podcast he talks a little about the evolution of the BCC’s standing rigging design and how Lyle Hess got it “almost perfect.”

Specifically, he mentions improving several BCCs to have the intermediates come over the lower spreaders with no aft lead so they provide better lateral stability for the mast and adding synthetic running backstays for heavy weather.

I’ve reached out to Brion’s colleagues to see if they have any records of BCCs being modified like this, but haven’t heard back yet. Has anyone had their BCC modified to this design by Brion?

We’re in the initial planning stages for a full refit before we start full time cruising, which will likely include a completely new rig, so this is the perfect time for us to figure out if there are any modifications we’d like to make and would love to hear folks’ thoughts.

Thanks, as always, for the help!
BCC #77

Mike: Thanks for that. I’m not a user of podcasts.

Brion Toss had given his critique of aft-led intermediate shrouds in Chapter 5 of his The Complete Rigger’s Apprentice. Toss started by analysing a Lyle C Hess-designed cutter rig for a 30 foot hull (‘Syrinx’).

Toss wrote:

"4. Aft-led Intermediates.
"By taking the intermediates off the spreaders and anchoring them a little aft of the mast, you can get them to function for both aft and lateral staying. The drawback to aft-led intermediates is that they don’t do either of their jobs very well. They don’t lead far enough outboard to provide optimum lateral staying, and they don’t lead far enough aft to provide more than trivial aft staying, because with even a minimal aft lead they interfere with boom travel and add to mainsail chafe.

"What is worse, their staying angle is so shallow that they add significant extra compression loads to the mast. So, once again, the mast must be heavier and the staysail smaller.

"I believe that aft intermediates are attractive partly because people don’t realize how ineffective they are, and largely because running backstays can be so very hard to use. As typically configured, tension is supplied by a block-and-tackle, usually 4:1. This configuration must be slacked away and taken up on every tack, a process which involves copious amounts of rope, and has blocks swinging around at head height. And for all this fussing, you get an anemic amount of purchase, not nearly enough to tension the forestay when it matters (i.e., clearing a lee shore in a blow). That is why, in our shop, we run a single-part runner through a single deck block, with a lead to the weather winch. Now you have 40:1 or the like, instead of 4:1, plus runners that set up quickly and slack instantly. No blocks to hit you, no heavy rigging flailing around and chafing the mainsail. The rope is Spectra until just above the block, where a fat piece of Dacron is spliced to it.

“The load on the deck block is higher by about 40 percent than with the older arrangement, owing to the angle departing the block, but this can be dealt with when selecting the block and the anchoring hardware”.

When I read Toss’s critique, I was not convinced. For sure, the intermediates add compressional load to the mast. On Zygote, I reckon the load from the cap shrouds and backstay mean the additional load from the intermediates is not significant.

My other difference from Toss’s recommendation was based on the addition of the runners (plus his suggestion of, for each runner, a deck-mounted block to turn the runner so it can be led fair to a winch, and so avoiding having a 2-part runner with a tackle). We’ve always sailed Z as a short-handed cruiser. Every extra bit of running rigging adds gear and a task - meaning extra duties for a short-handed crew and something else to clutter the working deck (including a potential toe stubber?)…

I therefore judged that the compromise of aft-led intermediates was quite practicable for a cruiser.

For an ocean racer, your judgment might be in favour of runners and the slightly larger staysail they might allow… .

Ahoy Bil and I hope all is well. You beat me to it, I hadn’t had a chance to grab my Rigger’s Apprentice off the shelf yet!

What he wrote parallels what he mentioned in the podcase, so if nothing else, Brion was consistent!

I am inclined to agree with you- one of the design elements I like about the BCC’s rig is the lack of running backstays. However, staring up at the rig a bit this weekend and I have to admit the angles are pretty small, so my engineer brain started thinking in sines and cosines, leaving me inclined to agree with Brion that they’re not as effective as they could be. Of course, the question is whether or not that matters.

In the podcast he mentioned only needing to use the running backstays in heavy weather. If that’s the case, then I don’t think it adds much work, but before I commit either way I have some more research to do, which is fortunate since I’ve still got about two years until I need to make final decisions about Cymba’s rig.

If what he mentioned is correct and he had modified several BCCs, I really hope I can find some of those folks to hear their thoughts.