Doing the toggle twist to keep our masts upright.
Issue 148: Jan/Feb 2023
I can’t dance; just ask my wife (cue chuckles). Given a tune, my twists, turns, and shimmies are as hopelessly misaligned as wearing roller skates on a pitching foredeck. Change the tune to rigging and I’m comfortable shaking it like nobody’s watching. Mast and rigging on a sporty day can also shake it, up-tempo jitterbug-like or intimidating Maori haka-style.
Dark rust stains suggest failing stainless steel, made unambiguous by the cracks in this lifeline turnbuckle.
Such vigorous moves might buckle my worn sailmaker’s knees almost as fast as a compromised shroud can bring a mast down. The difference is that my knees signal pending failure with a pain response. Rigging suffers in silence; its integrity is up to the crew. A rigger might signal the pain response, finding fault before problem, but how often is one onboard sleuthing out faults in your rig?
It’s up to the crew, even if they’re timid about tackling the physics, engineering, and material science knowledge of a skilled rigger. Breathe easy, sailors; there’s no math required. But you do need to find the pain points before anything buckles. You may not know how to correct the problem any more than I know what to do about knee pain. So bring on the pros with pride, knowing that good seamanship starts with finding faults before they fail.
Rigging that’s in pain shows. It’s not always easily visible, though, such as a headstay wire hidden inside roller furler foil sections or the bolts through a chainplate and bulkhead. Noticeable signs can be clues to unseeable rigging parts. A friend asked if it was worth removing chainplates for inspection. It’s a big job, but rusty red streaks below some of his chainplates hinted at necessity. I suggested an easy diagnostic check by removing a few bolts. A quick twist with a wrench and the bolt head fell out. Others followed. This simplified chainplate removal for full inspection.
Backstay chainplate with obvious rusty water stains and dark rust in the fasteners.
Stainless steel rusts when it is less resistant to corrosion. Causes vary, but sooner or later the effect is always failed metal. Rigging inspections don’t start with finding cracked metal. That is end-of-life metal and risky to sailors. Before then, the metal probably displayed markers in the form of rust.
A light orangey color is probably inconsequential staining, maybe from dirt or salt that held moisture on the surface. The consequential end of the rust scale is a dark, red-brown color. This color concentrated in a small area can indicate a crack or deeper pitting. Maybe the rust is splotchy over a large area and it’s difficult to see surface problems. Using a simple, small magnification device to see minute details more closely— like a 10X loupe (about $15)—reveals far more detail than with eyes alone. Inspect before polishing, focusing on darker rust stains. If necessary, clean rust or polish for a clearer surface view. If the rust returns relatively soon to a polished area, it’s another indicator that the metal no longer has its original properties. “Stainmore” steel is less reliable.
Inspecting a shroud with 10X loupe to sleuth out possible metal faults.
Poor quality stainless steel and the harsh saltwater environment often get blamed for stain-more steel. Often, though, stainless steel rigging is used in slightly flawed ways that degrade it prematurely. Where there is nuance and practice to reading rust stain “tea leaves,” flawed usage can be as obvious as a straight line that isn’t.
The shortest distance between two points is a straight line. With standing rigging, straight load paths are strongest for shrouds and stays. In rigging this is called alignment. Wire pulls straight easily, but the linking components at the ends can easily misalign. The consequence is unequal loading across components and cycle-loading.
A cycle load is one tension-and-relax sequence. Stainless steel can take many, many cycles, but eventually cycle-loading changes the metal so it becomes brittle. On the way to becoming brittle, it loses corrosion resistance and rusts—a clue.
Banana swage, causing misaligned wire with uneven loading across the 19 strands.
A fine example of misalignment is a bad swage, curved like a banana. Of course, this is not great for swage longevity and worse for the wire that exits the swage at a slight angle. Those 19 strands that make up the wire don’t do equal work. The wire is working at less than full breaking strength. Some strands carry little load. Others get overloaded and stretch more, cycle-loading faster to brittleness. To identify if the metal is screaming, inspect for darker concentrated rust areas at the top of a banana swage and on the wire strands just above it.
Another misalignment happens with toggles, the U-shaped component below a turnbuckle (among other places). Toggles allow rotation in connecting links, or mechanical articulation instead of hinging inflexible parts. Misalignment happens when the open end of the toggle shifts against a chainplate. One side is against the chainplate and it carries a higher load. The other side is offset and carries less load. The toggle twists, the open end spreads, the clevis pin point-loads, and nothing good comes of this. The solution? A few nylon washers in place to keep the chainplate centered inside the toggle. Even if they appear centered without washers, if there is a gap, the toggle will slide from side to side. Given time, the metal will weaken, rust, become brittle, and break.
Headstay toggle shifted to one side, with dark rust from failing stainless steel.
Nylon washers may be the cheapest, best rigging investment. While looking at lower toggles, peek at the angle of the chainplate relative to the shroud or stay attached to it. Aligned or misaligned? A misaligned chainplate is a boatbuilding defect. This may cause the chainplate to flex at the deck level. Correcting this is more involved than installing washers, but watching for and assessing rust is an early warning system. Dealing with it may be a pain in the knees, but having reliable rigging is peace of mind to dance upon the waves.
Jamie Gifford is a sailmaker/ designer, rigger, and recovered racing sailor. Since 2008, he and his wife, Behan, and their children cruise their Stevens 47, Totem, full-time, including a circumnavigation.
Thank you to Sailrite Enterprises, Inc., for providing free access to back issues of Good Old Boat through intellectual property rights. Sailrite.com
