Hall Spars ha desarrollado este nuevo sistema para trimar el mástil, que elimina tensores. La idea es muy simple y consiste en aplicar cuñas al obenque (las hay de distintos espesores) dentro de una caja que está laminada al mástil y que además posee una tapa para cuando se termina la operación poder cerrar ese espacio y que además evita que las cuñas se salgan cuando el obenque esta flojo. Este invento lo tiene el mástil del Volvo 70 Kosatka y se están desarollando tambien para dos Wallys.
Esta es la nota completa en inglés, extraída de sailingworld
A New Take on Rig Tune
Hall Spars unveils its adjustable, turnbuckle-free rigging for racing boats, and jumps into the carbon rigging game.
"Tech Review" from our January/February 2009 issue
22/01/2009
By Dave Reed (More articles by this author)
Imagine never again having to put tools to your turnbuckles in order to change your rig setting between races. No more inconsistency in the turns you put on one shroud or another. No more hastily turning your turnbuckle the wrong way and throwing the rig out of alignment. Imagine there are no turnbuckles—period.
To change your settings when the breeze builds or fades between races you instead send your crewman aloft with a handful of credit card-sized aluminum shims of varying thicknesses. He or she removes a small panel from the mast wall just above the spreader, and either inserts or removes a color-coded shim into an internal fitting buried inside the mast, returns the panel, and repeats the process on the other side. Your rig tune is complete—no tools, no turns, no sweat. And better yet, the rig is perfectly straight.
Enter the Brickhouse, a clever new internal shroud-adjustment system from Hall Spars and Rigging, which could—and I repeat could—forever change the way we tune our rigging. "There's nothing out there like it right now," says Hall Spars engineer Gunnar Salkind, who is credited with getting the Brickhouse out of the design phase and into production. "I wouldn't say it's never been talked about—it's just never been done."
The Brickhouse, which works in the same fashion as a mast-base brick setup, is a result of Hall's rig development with Team Russia's Volvo Open 70 Kosatka. As a means to reduce windage in the rigging, which is undoubtedly significant over 37,000 miles of racing, engineers sought a way to bury the standing rigging's shroud fittings inside the mast, thereby eliminating the presence of external fittings and turnbuckles at the spreaders and at deck level. The end result is what Salkind says is, "essentially a box" inside the mast.
It's very simple, he adds. Small wedges, or shims, are inserted into the box, which is just above the spreader. The box is positioned to match the angle of the diagonal shrouds where they enter the mast. Once the shims are inserted and the shrouds loaded, a removable cover keeps them captive should the diagonals become loose while sailing. There are currently seven aluminum shim plates of various thicknesses, each of which is based upon predetermined turnbuckle-turn ratios for Nitronic -40 rigging. For example, a 25-mm shim equals 16 turns, and so on. Shims of different thicknesses can be used in combination to achieve a desired rig setting.
In the case of Kosatka's mast, the Brickhouse fitting is a load-bearing piece tied into the interior mast walls. Getting it all inside the mast was an initial challenge for the engineers, says Salkind, given that their masts are "seamless" tubes. "It was a concept we had to come up with and make work," he says. "But it wound up being pretty easy." Exactly how they manage to get it in there, he adds, is proprietary.
As is to be expected, there were strong opinions tabled during the Brickhouse's development, says Salkind, from "it'll never work," or "it's too different than what people are used to." But he says everyone seems to be won over by it at the moment. "The only challenge now is that people are going to have to get used to it," he says.
Hall is already adapting the application beyond the VO70 and putting the system into rigs being built for a few larger Wally Yachts and a Judel/Vrolijk 60, which will launch in Europe this spring. Kosatka's unit is all carbon, but those going into the Wally rigs, says Salkind, are metal and can be taken it in and out of the mast.
There's certainly the potential of a quick trickle down into medium-sized raceboats and cruising boats as well. "It's really dependent upon the mast geometry," says Salkind. "For example, if the shroud end fittings are too large and don't fit into the rig because the rig is really small, then you won't be able to do it. There are a lot of other ideas we came up with when doing the Volvo rig of how to actually get it in there, so it might just have to be done differently for smaller masts. We have a lot of other ideas but they're still in development."It's not something you'd retrofit either, he points out. To do so would likely be costly, and in the end, it wouldn't be that simple.
While the tuning essentials are the same as with a standard turnbuckle setup, the procedure itself, of course, is not. As Salkind explains it (and admits this is by no means the definitive method), on the water, a crewmember must go aloft with the shims. To make room for the shims, the diagonal must be tensioned. With Kosatka's rig, a halyard is attached to a strop. The halyard is loaded up and then the crewmember switches shims to increase or reduce shroud tension. Drop the diagonal back down, and return the mast cover (think of it as a door in the side of the mast). As with tuning on any other boat, this can only be done to an unloaded leeward shroud while under sail. It's much simpler at the dock: remove the bricks out of the mast step to unload the rig and the shims come out by tugging on individual lanyards.
It is certainly different than breaking out the wrenches and applying turns to the turnbuckles at deck-level, and sending a crewmember a loft to make a change is something that Salkind admits may not be for everyone. But for racing programs that desire repeatable settings, it's well worth a trip up the rig. "It's just different," he says of the tuning system, "and [with this system] you have to have a set of shims in your pocket when you go up to change them."
Putting the benefit of reduced windage aside, Salkind says the system's second best attribute is the repeatability and accuracy they get with the shim system. For Team Russia they color-coded the shims and devised a chart showing what each combination of shims relates to in terms of equivalent turns on the rig. The seven shims allow them to cover the entire desired range of adjustment and guarantee consistency every time, which is not necessarily the case when applying turns at the turnbuckles. "On a J/24 for example, you're always winding the rig up and down and it never seems to be straight in the boat even though it should be," says Salkind. "With something like this, you get better repeatability; you have a far better chance of keeping the rig straight."
