The Standing Rigging
There is the age-old debate for when the correct time is to replace a yacht’s standing rigging. All my rigging has been changed at least once over the thirty-one years that I have owned Sumara. With my planned expedition trip to Scoresby Sund in 2022, I decided to take the plunge and replace all the standing rigging and the halyards. My old policy was to replace a couple of shrouds each year, but I have rather lost track of the paperwork and it seemed more straightforward to just renew everything in one go.
I have chosen to use KOS stainless wire rope (316 grade) for all the 1 x 19 shrouds. KOS wire has a good reputation and, when viewed alongside other brands, it is noticeably smoother. The shrouds are all 6 mm diameter except for the twin backstays which are 4 mm. The breaking strength (BS) of the 6 mm wire is given as 2,878 kg. The 4 mm wire has a BS of 1,285 kg. Although the combined strength of both backstays falls short of the BS of the forestay by 308 kg, it is not a problem because the included angle between the twin backstays and the mast is far greater than that of the forestay, so less strain is exerted on the backstays.
The initial constructional stretch in the wire varies between .025% up to .1 % as the strands bed in. To allow for this, I usually remove .05% from the overall length of the wire rope assembly. Realistically the rigging screws can easily absorb this small amount of constructional stretch. Once the wire has bedded in there is some elastic stretch which can be calculated using Hooke’s Law but life is too short to worry about this minimal amount.
Most of the roll swage fittings are selected from Sta-Lok’s range with the exception of four shrouds which required an eye big enough to take a 12 mm hex bolt. I chose Blue Wave swages for those shrouds. The rigging screws are all Sta-Lok chromed bronze type B24 with strap toggles to the chain plates. I like strap toggles to ensure full articulation. I have ordered lock nuts for the rigging screws to allow for easy early season adjustments to be made before the split pins are finally inserted.
I have posted the complete parts list and lengths in the download section of this website together with the old rig tensions as of September 2021 measured with a Loos gauge before the mast was unstepped. It was set up evenly at the start of the season so obviously a mid-season rig tension check would have been helpful. However, at no point was there any slackness in the lee shrouds which is a very good sign as slackness causes extra stress. I’ll re-check all the rigging tensions after sailing a few hundred miles and again mid-season in future.
As I have some qualifications from the Lifting Equipment Engineers Association and have carried out thousands of wire terminations and inspections, I will be swaging all the fittings myself using a WireTeknik A200 hand roll swaging machine mounted on a PlanKform in my garage. The machine will swage up to 8 mm diameter wires. I’ve borrowed this machine from Arthur Beale to complete this job.
Roll swaging is a relatively simple process requiring a bit of arm strength for the manual hydraulic pump. The crucial thing is that the correct swage is selected for the wire and the correct rollers are used on the machine. All the calculations have already been carried out by the boffins so there is no need to proof load, but it is essential the swage diameters are measured after rolling to check they are within the tolerances given. It is also important the wire is inserted fully into the swage prior to swaging and marked with a Sharpie at the exit point. It can then be held against the swage on the outside and the swage marked where the rolling needs to commence. It will also quickly show you if some foreign object has got into the swage. The Blue Wave swages are clearly marked with a line where the roll compression needs to start. It would be nice if Sta-Lok could do the same.
My old rigging had a copper sleeve compressed onto the wire over the lower spreader and a cable grip under. This time I will be using stainless steel split collars to locate the spreaders.
The main, Yankee and stay halyards have now all been remade using 10 mm Liros Herkules in a classic beige colour. Herkules is a high tenacity polyester rope with a good breaking strength of 2,549 kgf and a robust hardwearing construction. For cruising halyards, I reckon it to be the ideal rope. The working stretch of this rope is low at less than 5%. However, it doesn’t hold knots very well, so I personally wouldn’t consider it for sheets, although Liros recommend it for this use. I always secure my sheets to the sails with a bowline, I suppose if you use a soft shackle or suchlike then Herkules would be a suitable rope for making sheets. For Sumara’s sheets I prefer to use the softer Liros Seastar which has a matt finish but a lower breaking strength of 1,937 kgf and a bit more stretch.
I have spliced a thimble eye into the ends of all the halyards using the excellent Blue Wave thimbles which seem tougher than most. The splices were following “Splicing Modern Ropes” technique rather than the Liros instructions. The Liros technique leaves the outer cover outside the splice and it is then hidden under a whipping. The “Splicing Modern Ropes” technique tucks the outer cover down inside the rope and only requires a whipping on loosely laid ropes.
I like to avoid captive snap shackles in halyards in case I want to use the halyard for mast climbing. I feel more secure clipping into the thimble eye with a climbing karabiner rather than relying on a marine snap shackle.
I finished the tail end of the halyards with a Flemish eye so they can be reeved with a mousing line if necessary.
Sumara is 26 ft long and weighs 5 tonnes. For my mooring lines I use a 16 mm diameter three strand spun polyester rope in a classic colour. It happens to be a Liros product with a breaking strength of 2,200 kg and a working stretch in excess of 15%. Personally, I don’t like Nylon ropes for mooring. Although Nylon is stronger (although it loses some strength when it gets wet) I find that it is just too stretchy. In gale force winds with Nylon warps, the boat would be able to surge along the pontoon potentially colliding with other boats or walkways. I have never found my polyester warps to cause any snatching and I don’t use any fancy gizmos. I also believe Nylon tends to go stiff after a few years.
If I was Channel cruising I would probably have chosen 14 mm diameter warps, but for Northern areas I find a bit of extra diameter is reassuring. Don’t over do it though, as ropes can be heavy especially if you need to throw them ashore. The Liros Classic rope is very soft to handle and easy to coil. I like to put an eye in one end of each rope. The internal length of the spliced eyes is 450 mm and the springs have black polyester tubing slid around the eye. This helps to instantly recognise the springs from the shorter bow and stern lines.
Length wise, my springs are 15 m long and the bow and stern lines are 9 m. I would normally have used the formula of one and a half boat lengths for the springs and one boat length for the bow and stern lines. I increased the springs’ length because I may transit the Caledonian canal in a couple of years and 15 m is their recommended length. I tagged on an extra metre to the other lines to help when moored against tidal harbour walls. I also carry a shorter mooring line normally only used if I am moored in a finger berth and can use an extra short line to pull the bow off the finger pontoon. If I am rafted out, the mooring lines will often reach as shorelines and I have lots of suitable sheet lines that can be pressed into action.
I also carry 60 m of 16 mm polyester Octoplait in a special bag. It is used as a shoreline in certain anchorages or to haul the yacht off a wall in stormy harbours. I also use it for kedging off if I accidentally hit a shallow patch. The rope flakes down into its bag and behaves impeccably. Splicing it is a bit tricky but I have loaded a video of my technique below.
The Classic Colour!
Most of the ropes below were described as “Classic” in colour. Maybe we need an ISO standard!