Which Book On Rigging?

[sailaway21]

Good Old Boat in their Sept/October issue of 2006 had a quite good article on the subject, including use of the Loos guage. Wire rope stretches only 1% before parting so it is difficult for the Mark 1, Model 0, precision hand to get a feel for the actual tension on it. The guage is a good investment that will serve you year after year. Think of it as you would a tire guage to your car.

[SEMIJim]

Yeah, I've pretty much decided to get the gauge. Just need to figure out which size for my Pearson P30, and whether the "economy" model will suffice, or if I really have to pay $100 - $150 for the "pro" model.

I figure that gauge, and The Complete Rigger's Apprentice, ought to get me on the right track.

Thanks for your comments and votes, everybody!

Jim

[tenuki]

Originally Posted by blt2ski

Tenuki,
If you are around sunday, my kids and I are installing a harken upwind traveler system, should be better than the push/pull pin to set where the traveler needs to be!

Marty

well darn it, I'll be out of town this weekend. btw, are you doing the foul weather bluff race this year? I'm thinking I'm gonna try to crew it this year to get a feel for it before I race next year. (no new sails in this years budget.) send me an email if you know someone who needs crew.

btw, I had to order the other size gauge today, my friend's cape dory 28 is needing some love and he's too cheap to buy one. lol. I have this tool buying logic. It goes something like this. Is it a tool? if yes, buy.

[Sailormann]

You don't need the "Pro" model. The gauge should not cost you more than about $75.00. They come in two sizes, sizing is determined by the gauge of the wires they can handle. Get the larger one. Not sure what you are referring to when you mention unreliable, they are about as simple a piece of machinery as exists. If you have hand tremors, or are really hung over and shaking, you're not going to get a reliable reading, but if you can hold your hand steady for a few seconds - it is very, very simple.

They last about four or five years if you use them a lot, eventually they get fatigued and are unreliable. I am pretty much a seat-of-the pants sailor, and don't cotton much to all this newfangled technology, but the Loos gauge is pretty well a necessity if you want a SAFE rig.

Sailing around with vastly different tensions in your shrouds is just begging for catastrophe.

[blt2ski]

hmmmm......yes will be doing FWB. With original 22 yr old dacs. Hopefully not light winds ie less than 5 knots like last year. Boat does nt do well. But if a blow, ie above 10-15, I can compete reasonably well. Not sure if sails are real quick in future.

I will be glad to borrow the bigger loos guage!

[Tartan34C]

First, I have no real world experience with the Loos gauge but understand from a paper I read that it was used to validate lab testing that was done on a test mast section. Using the Loos gauge they compared that data to an actual boat instead of using strain gauges on the boat. Before using the gauge for this they tested the gauge using a known tension and found it to be accurate enough for this use. So at least in my mind the gauge is suitable for its intended purpose. Instead of the Loos gauge I use the bowstring method and have found it adequate, simple and fast.

With the reliance on this gauge are you missing the more important variable. The actual tension in the wire doesn’t matter much but the mast must stay in column under sail. That is to say the individual wires will each have a different tension at the dock because of wire length, the geometry of the rig and other factors even as it works together as a system and keeps the mast in column under sail. You need to adjust the rig at the dock so that the mast is straight and centered in the boat with the proper amount of rake. Then sail the boat to adjust the tension so that the mast stays straight on each tack. I think you will find that the tension in the wires will be very different after tuning under sail then it was in your preliminary tuning dockside using any gauge.

Because the rig needs this tweaking under sail I think the Loos gauge is unnecessary. You can just center and rake the rig and pull the wire as you do with the string in a bow to get close enough before doing the final tuning under sail. I think it’s a mistake to equate safety in the rig to an arbitrary preload in the wires. Instead you need to look at the mast under load and make sure it stays straight or in column. I know a gauge is easy to use and may put your mind at ease but it’s looking at something indirectly and not guaranteeing that the mast will be straight when you most need it to be. A safe rig is a straight rig.
All the best,
Robert Gainer