Inspecting, Maintaining and Replacing Standing Rigging

By Duncan Kent

August 14, 2015

It’s one of the most important features on a sailboat, but many owners put standing rigging at the back of their minds when it comes time to do their pre-season safety checks. A prudent sailor should inspect his or her standing rig at least once each season and should know when the time comes to replace most or all of it.

I don’t want be a scaremonger, but standing rigging has so many possible failure points that regular inspections should really be part of every pre-cruise integrity check. Yes, it’s unlikely you’ll suffer a massive failure during normal coastal cruising, but it is good practice to spend a little time looking carefully at each element of your rig at least once a month, or before a cruise lasting more than a few days—particularly if heavy weather is expected. A detailed rig check takes no more than two hours or so to complete—about as long as it takes to provision the boat with a week’s food supplies—only the result of not doing it can be a good deal more drastic!

Most insurance companies reckon you should replace your standing rigging about every 10 years. Sometimes they let you go longer if you have the rig professionally inspected, particularly if you have an electronic check carried out on the terminals and other crucial fittings. The wire itself rarely fails midway along a shroud, so this makes good sense. There’s no reason good quality rigging shouldn’t last up to 20 years or so if it is well maintained and any problems that arise are sorted right away.

Inspecting the standing rigging

Before you contemplate the task of renewing your standing rigging you need to thoroughly inspect all components at close quarters to find out exactly what needs to be replaced and what items can be safely transferred to the new rig.

Start by digging out the bosun’s chair and finding a trusted (and hopefully fit) buddy to help you. The masthead is a good place to start, and while you’re at it, it’s worth looking closely at the mast as well as the rigging, to see if any corrosion, cracks or weld defects are evident. Most masts have integral sheaves, which are rarely serviced except when the mast is unstepped—often only at five-year intervals. Check and make sure the sheaves run freely, that the bearings are not worn oval and that the retaining pins are secure. Now would also be a good time to change those old cotter pins and circlip rings as well. Have a feel for any rough or sharp edges, especially cotter pin ends that might chafe lines or sails.

For those with external halyard blocks, check to make sure all lines run freely and that block bearings aren’t worn. Ensure swivels are working and remove any shackles. Clean and lubricate them, then refasten them, and remember to mouse them with new galvanized wire and tape over the ends to avoid chafe.

Next check the back and forestay fittings where they connect to the mast, ensuring any clevis pins are straight and secure. Inspect the area around tang plates and toggle fittings for cracks, preferably using a magnifying glass. One of the most common areas of rig failure is where the shrouds terminate—both at the mast tang or socket fitting and the wire terminal, toggle or T-ball. While it’s often difficult to know whether, say, a swaged terminal is in good condition, there are a few common signs of possible failure to look for. First, check for cracks (usually longitudinal), particularly if the terminal looks misshapen or the stay is misaligned in any way. Also look to see if there are any broken wires where the shroud enters the terminal. If in doubt, get your deck buddy to rig temporary stays using the halyards and check each stay—one at a time—with it slackened off. With the tension off it’s a lot easier to waggle the terminal around and check closely for cracks, wear, distortion or corrosion. The latter is very important, as it’s a common cause of weakness, so wherever possible ensure stainless steel fittings are insulated from an aluminum mast.

As you work your way down the mast, take a glance at the mainsail track to see if it’s in good condition and well secured. Now is a good time to give it a quick spray with some track lubricant as you descend. The next area deserving close scrutiny is the spreaders. These carry a good deal of compression load, so check their roots for damage and make sure the spreaders aren’t bent in any way—they should exactly bisect the angle of the shroud. Spreader tips that are covered can often encourage and hide corrosion as they can trap water and reduce air flow over stainless steel fittings, causing them to corrode. (This is true anywhere there are stainless fittings by the way, so be wary of putting too much tape or tight-fitting covers on them.)

Don’t forget the turnbuckles and chain plates. The former need careful scrutiny and often sustain damage from misalignment. They can also crack under the constant tension, particularly if the rig has been “pumping” in rough seas or if the toggles that ensure proper shroud alignment have seized and can’t move freely. The screw threads and locking nuts need regular cleaning and some light greasing to prevent corrosion. It’s best to slacken them off, giving them a few turns each way and removing any clevis pins for close inspection before re-tensioning the shroud or stay and then locking it off with new split rings or cotter pins.

With chainplates it’s often not the actual hardware that fails, but the structure that supports them. If the baseplates, for example, are leaking, water will penetrate the deck, making the surrounding deck core mushy and weak (if a core exists) and possibly compromising supporting bulkheads and structures belowdecks. Before long this will create slack in the rig, generating bends and stresses elsewhere. The worst-case scenario, of course, is that the chainplates pull right out of the deck, with catastrophic consequences.

RIGGING TIP:
Why not fit a pair of mast steps a few feet from the masthead to give you a solid base on which to stand while you’re working up there, rather than hanging uncomfortably in the bosun’s chair?

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Take this opportunity to check out your spars as well. Take a look at your mast step—particularly if your mast is keel-stepped, as bilge water can cause serious corrosion at the foot of the mast. (Deck-stepped masts are less prone to corrosion as the foot of the mast is open to the air and can dry quickly.) Another trouble spot on keel-stepped masts is where the spar enters the deck, especially if water has leaked under the mast collar. Lastly, check your boom, starting with the gooseneck, mainsheet and vang fittings, where huge forces are applied when the rig is under load. Look for cracks, corrosion and worn clevis pins or shackles, removing any tape and replacing cotter pins and split rings where necessary. Inspect any integral reefing sheaves or bearing wear or UV degradation. Small dents in either the mast or the boom are often hotspots for failure, as they weaken the form of the spar.

Replacing the standing rigging

Assuming you have decided to replace the rigging wire as well as a number of other components, the first decision is whether to do it with the mast up or down. It’s always advisable to unstep the mast every few years to check it over thoroughly at ground level, so this is an obvious time to consider replacing the shrouds and stays, particularly if the forestay is to be replaced, as removing the furler without damaging it can be a tricky task.

That said, it is perfectly possible, though somewhat tedious, to change shrouds and stays in pairs with the mast up by using halyards and intermediate tackles to support it. Probably the trickiest will be the forestay and backstay, as these carry the greatest loads, although all the standing rigging can be loosened to some degree when at rest. Depending on the spreader joint, cap shrouds can sometimes prove troublesome as well, often requiring the spreaders to be disconnected at their roots.
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The golden rule has always been never to work on a rig with the boat out of the water. I can only assume this is due to the risk of rocking the hull off its jackstands. If your boat is in a full cradle, however, this shouldn’t be an issue.

When inspecting your rig you should also make an inventory of all its parts and their dimensions. Note wire and pin diameters and measure the wires as accurately as possible between pin centers with the rig fully tensioned. For later reference, photograph each wire end, terminal and mast attachment—ditto for the lower ends, turnbuckles, toggles and chainplates—taking careful note of the positions of the turnbuckles. If the wire in a stay or shroud has stretched to the point where there’s no room for further adjustment, make sure you compensate for this when replacing the wire so that at least one-third of the turnbuckle body is open to accommodate adjustments when the rig is fully tensioned.

Terminals and fittings

Regardless of what fittings you currently have the choice for multi-stranded wire rigging is between swaged terminals or mechanical fittings. The former requires someone with a swage machine to fit terminals, the latter you can fit yourself—with care. The mechanical terminals most commonly used by DIY riggers are Sta-Lok and Norseman terminals.

It’s common to choose to fit lighter swaged terminals at the top of a stay or shroud and mechanical ones at the bottom, where swaged terminals are more vulnerable to corrosion. This way you can cut the wire roughly to length and have a rigger swage the tops, fit them in place yourself and terminate the lower ends to suit.

Shrouds and stays should be replaced in pairs, applying just enough tension to support the mast with you climbing it, but not tuned to sail. With the forestay removed, take the opportunity to fully service your headsail furling gear as well.

There are some question as to whether or not you should replace your turnbuckles along with the wire. Personally, I’m in favor of it, but if you replace the standing rigging frequently—every 10 years, say—then it might not be necessary. Do disconnect them and inspect them very carefully for cracks on a well-lit workbench. If you suspect a possible crack, try running some dye over it—the crack will become much more obvious that way. And never forget the golden rule: if in doubt, sling it out.

You will most likely also need (or want) to replace toggles and cotter pins, even if you keep the turnbuckles.

Tuning Your Rig

When you’re happy everything is in place, it’s time to tune your rig. Most sailors choose to leave this to a professional rigger, but there’s no reason why you shouldn’t attempt it yourself if you know the best way to go about it. Low-cost tension gauges are now available and are a useful addition to your cruising toolbox anyway.

Start at the bottom, working your way up from the lowers, to the cap shrouds and finally the stays. Keep the tension equal on each side by counting the turns on each turnbuckle. Do a few turns on one side before going to the other and applying an equal number. This way you won’t risk deforming the mast or pulling a fitting out of line.

Photos by Duncan Kent and Peter Nielsen