All about rope - Part II, Cordage care

by Mark Cherrington on 30 Sep 2009 Mark Cherrington continues his article on rope - this week he talks about caring for your lines to make them last longer: (For Part I of this series, click http://www.sail-world.com/CruisingAus/All-about-rope---Part-I/61520!here. )

The good news is that today’s high-tech ropes are extremely tough and long-lasting, and will stand up to a reasonable amount of abuse.

Polyester fibres give excellent UV resistance and getting (and staying) wet won’t harm them. As a rule, you should get at least five years’ life from these lines, and probably more if they reasonably well looked after, not overstressed and the jacket stays in good shape.

The exception to the high-UV resistance is the synthetic cores; the polyester cover provides adequate protection, but if it gets cut, worn or frayed, the Vectran or Spectra core can break down and fail within about 18 months.

However, products are available to provide additional UV protection for Vectran or Spectra cores. You will also increase the life of your lines if you can wash them out in fresh water as often as possible. Dried salt water leaves salt crystals in the rope, which will cause abrasion and swelling.

A heavy shower of rain can be as effective a way of washing salt out of ropes as any other alternative; hang them off your safety lines neatly coiled, so they can get wet, and then dry easily.

So how can you tell if a rope is about to fail? It’s really a matter of commonsense and observation, keeping an eye out for abrasion and chafing damage.

Aside from a high-tech synthetic line where the core has been exposed to sunlight for extended periods, the main killer of ropes is likely to be abrasion – which is where polyester is more vulnerable.

Regularly check all wear points, especially before heading offshore or if you’re planning a longer trip.

Any rope with a damaged covering should be replaced. It’s not just the issue of possible loss of strength; a frayed line is much more likely to get caught in a sheave, block or rope clutch at a crucial time.

Older ropes also get harder to handle; they get 'furry' and start shedding fibres. There's more friction build up, so they are more effort to pull in or ease off.

I recently had one old mainsheet literally fall apart in my hands. It was a gusty day on the harbour, so it was getting a lot of work through the jam cleat. By the end of the day, there were bits of rope lying all over the floor of the cockpit.
Well overdue for replacement.

Selection:
Phill Bates' advice is to select ropes depending on how you are using your boat. 'If you are racing seriously, you need to go for the more high-tech lines, and you'll definitely get better performance. But if you're spending most of your time plodding about harbours and coastal waters with the family, low-tech ropes are fine,' he says.

'However, if you are heading offshore, you do need to look at ensuring you have the right ropes for your applications.
Chafing is a big issue; be sure you have your boat set up so you don't have any problems with rope breakage in the short term.

'If you've chosen good quality ropes, and set up your boat to minimise the chances of chafing you should find there is no need to replace any of your ropes until five to eight years down the track,' says Bate.

If you're making the switch to the high-tech, high strength lines, rope strength won't be your only consideration. Consider also the cleats that have to hold the very strong, thinner ropes.

'With modern ropes, a critical issue is holding ability,' says Bruce Clark, 'You can put an 8 mm Vectran halyard on a 40 ft yacht, but you won't find a jam cleat strong enough to hold it. Unfortunately, jam cleat technology has not moved along with rope technology.'

Another issue is what's comfortable to handle.
'You need to specify a rope that's comfortable in your hands,' says Clark,'My rule of thumb is that the minimum diameter of a sheet that you're going to be holding/adjusting all the time is 8 mm. If you've got a 6 mm line and your hands are cold and wet, very quickly it's going to feel like a piece of piano wire in your hands.'

As a hypothetical exercise, we asked Clark to consider line replacement on a 40 ft cruising yacht.

'One of the first issues you'll need to look at is your self-tailing winches. A lot of the older winches, set up for 14-16 mm double-braid polyester sheets won't be able to handle a switch down to 10-12 mm Spectra because the rope will be too skinny for the jaws,' he says, 'So you may be up for new self-tailing winches as well.

'However, if you are looking at replacing sheets, I would recommend looking to the Spectra-type product. Because you can go for a lower diameter, there's less friction through the blocks and so it's easier to use.'

Conclusion:
Many of the marine cordage options available to today’s cruising sailors have their origins in high-tech racing yachts; once proven in these applications, they tend to filter down to the 'consumer' end of the market.

However, for many cruisers, the tried and true double-braid polyester ropes will remain their best choices for most applications. Selection is going to depend on your application, how you use your boat and your budget.

Rope wear checklist:

1. Top of jib furler. Because this is rotating all the time, andit's high up and out of sight, wear won't be immediately obvious. Especially check where the halyard goes through the bale; some designs result in early, severe wear and you do not want this failing during a storm!

2. Rope clutches. Because these rely on friction to hold, they are going to induce abrasion, especially on polyester jackets. Regularly inspect these for wear; if the jacket comes apart, it will bunch up and jam.

3. Mast base. There's always a few blocks here where halyards, reefing lines, topping lifts, etc turn and go up the mast. If the base is set up poorly, the blocks will get interwoven and the halyards going through them will get caught on the edges. That can strip the jacket in no time.

4. Jam cleats: If you’re constantly adjusting a setting, say for your mainsail, this will be an area of additional wear.

5. Other wear areas: Every boat is different and is going to present different wear areas for ropes. For example, do your jibsheets get caught up around your shrouds and chainplates? If you have to tug them free, they could be experiencing extra wear. Check your traveller adjustment, where it's easy for ropes to get twisted, jump off sheaves and start wearing. Take the time to walk around your boat and check for worn ropes, or dags or furriness in the rope jacket.

Tidy tails:
OK, hands up who has merely sealed their sheet and line ends with a match or hot knife? I plead guilty to this in the past: very unseamanlike, but I'm working my way through my sheets and halyards!

The correct practice is to properly whip the line, which will ensure the core and covering are properly held together.
If you don’t feel up to this, and insist on doing the cheap and nasty way (match or hot knife), first slide the covering back so about 25 mm of core is showing. Cut off the exposed core, then work the covering back over the end. Now when you melt the cover, at least it will shrink and seal around the core.
However, whipping the end remains the best long-term solution; it's easy and doesn't take long.

Knot strength:
It’s common comment that knots can reduce by up to 30-40% the strength of a rope, due to the tight curves involved.
But according to some manufacturers we spoke to, today’s high-tech lines will only lose about 15% of their strength when knotted. However, that has not been the experience of a couple of riggers we spoke to.

Bruce Clark of Sydney Rigging won't