Probably a silly question - headsail sheets

A mate of mine bought a job lot of GPO braided rope. He couldn't work out why his sails kept flapping after initial trimming.

Turned out that the rope was designed for going up telegraph poles etc with a fair bit of give. I assume similar to climbing rope.
It is exactly that. 75kg of climber on 50 metres of rope will bounce about a metre if provoked. So say half that on s halyard on a medium cruiser. 75kg halyard tension stretches nearly half a metre. Plus, its non linear.
 
It is exactly that. 75kg of climber on 50 metres of rope will bounce about a metre if provoked. So say half that on s halyard on a medium cruiser. 75kg halyard tension stretches nearly half a metre. Plus, its non linear.

Last time I saw Climbers rope ... it wasn't that 'stretchy' ... in fact far from it ...

My posts are based on rope I've seen and handled before ... climbers rope today is not on my working list !!

If todays rope stretches like that - then I agree its not fit for the job on a boat ...
 
Last time I saw Climbers rope ... it wasn't that 'stretchy' ... in fact far from it ...

My posts are based on rope I've seen and handled before ... climbers rope today is not on my working list !!

If todays rope stretches like that - then I agree its not fit for the job on a boat ...
It’s been like that since the late 80s at least. You can see the reasons why. Its to absorb a shock load without breaking the back of the falling body. Its a sigmoid stretch curve, as little as poss at 75kg, and up to 40% elongation at max load, after which it stretched little more. Max load is a 1 off, donate it to mooring lines after a hard fall.
 
It’s been like that since the late 80s at least. You can see the reasons why. Its to absorb a shock load without breaking the back of the falling body. Its a sigmoid stretch curve, as little as poss at 75kg, and up to 40% elongation at max load, after which it stretched little more. Max load is a 1 off, donate it to mooring lines after a hard fall.
Last time I went climbing was in mid 80's at Weirwood Reservoir Rocks ...
 
It seems the term "climbing rope" needs some clarification for non-climbers.
  • Dynamic rope. Most widely speced as UIAA single, double, or twin ropes (3 slightly different rope tests for slightly different uses), these are stretchy nylon ropes with tightly braided covers for abrasion resistance and very high energy absorption capacity. Built to absorb a LONG fall without injuring the climber or overstressing the anchors. I once caught a fall of nearly 100 feet, no injury or damage to the rope or anchors. All tend to have a very similar feel.
    • They have parallel cores for maximum fatigue resistance and maximum cut resistance over edges.
    • 50% of the core is S twist and 50% Z twist so that they do not rotate under load.
    • Test requirements include a minimum number of very severe drops over an edge (most non-UIAA ropes cannot survive one test drop), maximum impact force (both to protect the climber, and just as importantly, to reduce stress on the anchors), and maximum stretch (not too much stretch to reduce chance of ground or ledge impact).
    • Maximum stretch under body weight. Too much stretch is annoying when hauling or climbing the rope.
  • Static rope. Typically built something like yacht double braid, but with a tighter cover. The big market is industrial and arborist work, so these are rugged ropes. Often stiff, to survive abuse lowering things like tree limbs. Much variability.
    • A minimum strength requirement, based on code requirements, typically about 6000 pounds.
    • Maximum stretch. Sometimes semi-dynamic properties are included.
These are VERY different ropes, with very little in common. They are not used for the same purposes, any more than Amsteel and polypropylene floating rope are interchangeable.

When climbers refer to "climbing rope," they nearly always mean dynamic UIAA single ropes, since those are by far most common for recreational climbing. My traveler line is a UIAA half rope, which is slightly thinner than a single rope.

The first time I went climbing with a rope was in 1979. The last time was ... last week. I think I'll buy a new rope soon. My current one is getting a bit furry.
 
It seems the term "climbing rope" needs some clarification for non-climbers.
  • Dynamic rope. Most widely speced as UIAA single, double, or twin ropes (3 slightly different rope tests for slightly different uses), these are stretchy nylon ropes with tightly braided covers for abrasion resistance and very high energy absorption capacity. Built to absorb a LONG fall without injuring the climber or overstressing the anchors. I once caught a fall of nearly 100 feet, no injury or damage to the rope or anchors. All tend to have a very similar feel.
    • They have parallel cores for maximum fatigue resistance and maximum cut resistance over edges.
    • 50% of the core is S twist and 50% Z twist so that they do not rotate under load.
    • Test requirements include a minimum number of very severe drops over an edge (most non-UIAA ropes cannot survive one test drop), maximum impact force (both to protect the climber, and just as importantly, to reduce stress on the anchors), and maximum stretch (not too much stretch to reduce chance of ground or ledge impact).
    • Maximum stretch under body weight. Too much stretch is annoying when hauling or climbing the rope.
  • Static rope. Typically built something like yacht double braid, but with a tighter cover. The big market is industrial and arborist work, so these are rugged ropes. Often stiff, to survive abuse lowering things like tree limbs. Much variability.
    • A minimum strength requirement, based on code requirements, typically about 6000 pounds.
    • Maximum stretch. Sometimes semi-dynamic properties are included.
These are VERY different ropes, with very little in common. They are not used for the same purposes, any more than Amsteel and polypropylene floating rope are interchangeable.

When climbers refer to "climbing rope," they nearly always mean dynamic UIAA single ropes, since those are by far most common for recreational climbing. My traveler line is a UIAA half rope, which is slightly thinner than a single rope.

The first time I went climbing with a rope was in 1979. The last time was ... last week. I think I'll buy a new rope soon. My current one is getting a bit furry.

I've had Arborist twice over last few months working on my estate ... was interesting seeing him set up his safety and main ropes ...
Until you posted that - I'd forgotten about him. The ropes were all in special bags - that as he set the ropes - they fed out ...
When he finished the job - he was pretty quick coiling them back in respective bags.

While in one tree - he found a Hornets nest .. I was amazed how quick he transferred from main rope to secondary to swing out of the tree before they 'got him' ... literally if I had blinked - I would have missed it ! Thinking back - there was very little stretch / bounce ...
Out came a spray he carries ... projects for up to 4 - 5m ... he sprayed and left that tree till next day ...
 
It seems the term "climbing rope" needs some clarification for non-climbers.
  • Dynamic rope. Most widely speced as UIAA single, double, or twin ropes (3 slightly different rope tests for slightly different uses), these are stretchy nylon ropes with tightly braided covers for abrasion resistance and very high energy absorption capacity. Built to absorb a LONG fall without injuring the climber or overstressing the anchors. I once caught a fall of nearly 100 feet, no injury or damage to the rope or anchors. All tend to have a very similar feel.
    • They have parallel cores for maximum fatigue resistance and maximum cut resistance over edges.
    • 50% of the core is S twist and 50% Z twist so that they do not rotate under load.
    • Test requirements include a minimum number of very severe drops over an edge (most non-UIAA ropes cannot survive one test drop), maximum impact force (both to protect the climber, and just as importantly, to reduce stress on the anchors), and maximum stretch (not too much stretch to reduce chance of ground or ledge impact).
    • Maximum stretch under body weight. Too much stretch is annoying when hauling or climbing the rope.
  • Static rope. Typically built something like yacht double braid, but with a tighter cover. The big market is industrial and arborist work, so these are rugged ropes. Often stiff, to survive abuse lowering things like tree limbs. Much variability.
    • A minimum strength requirement, based on code requirements, typically about 6000 pounds.
    • Maximum stretch. Sometimes semi-dynamic properties are included.
These are VERY different ropes, with very little in common. They are not used for the same purposes, any more than Amsteel and polypropylene floating rope are interchangeable.

When climbers refer to "climbing rope," they nearly always mean dynamic UIAA single ropes, since those are by far most common for recreational climbing. My traveler line is a UIAA half rope, which is slightly thinner than a single rope.

The first time I went climbing with a rope was in 1979. The last time was ... last week. I think I'll buy a new rope soon. My current one is getting a bit furry.
The ropes I use are Triple rated ropes, around 9mm (not described above), and also static ropes 14mm used in mountain rescue, and retired after little use. I climb a lot and wear out my sport climbing ropes in 2 or 3 years. I tested the retired climbing ropes and cheap chandlery ropes, by winching, the alleged chandlery sailing ropes stretched more than the climbing ropes, probably because they are poor quality, sold to unsuspecting sailors, while my climbing ropes are the best money can buy. Examination of the sailing ropes revealed to me that essentially they were pretty poor quality in the opinion of somebody used to handling ropes daily, (particularly the sheath)
 
The ropes I use are Triple rated ropes, around 9mm (not described above), and also static ropes 14mm used in mountain rescue, and retired after little use. I climb a lot and wear out my sport climbing ropes in 2 or 3 years. I tested the retired climbing ropes and cheap chandlery ropes, by winching, the alleged chandlery sailing ropes stretched more than the climbing ropes, probably because they are poor quality, sold to unsuspecting sailors, while my climbing ropes are the best money can buy. Examination of the sailing ropes revealed to me that essentially they were pretty poor quality in the opinion of somebody used to handling ropes daily, (particularly the sheath)
The reason marine rope covers are relatively loose, compared to climbing rope (climbing ropes have very tight covers to prevent snagging and resist abrasion on rock crystals), is so that they can be easily spliced. A marine rope that is a battle to pull the core or to over-stuff at the throat of an eye splice will not sell. Climbers, on the other hand, mostly don't splice, among other reasons, because the eye would catch in a crack when you pull the rope.

Climbing ropes are generally impractical to splice (not impossible, just ridiculously difficult). If an eye is desired, they are more often sewn.

So they have their reasons.

---

My first rope was 11 mm. That's what single ropes were in the 70s, and a fall rating of 7 was consider a lot. Now, I swear my ice ropes are so thin they look like dental floss. Evolution.
 
The reason marine rope covers are relatively loose, compared to climbing rope (climbing ropes have very tight covers to prevent snagging and resist abrasion on rock crystals), is so that they can be easily spliced. A marine rope that is a battle to pull the core or to over-stuff at the throat of an eye splice will not sell. Climbers, on the other hand, mostly don't splice, among other reasons, because the eye would catch in a crack when you pull the rope.

Climbing ropes are generally impractical to splice (not impossible, just ridiculously difficult). If an eye is desired, they are more often sewn.

So they have their reasons.

---

My first rope was 11 mm. That's what single ropes were in the 70s, and a fall rating of 7 was consider a lot. Now, I swear my ice ropes are so thin they look like dental floss. Evolution.
Ok, thanks for explaining the loose sheath.
 
Ok, thanks for explaining the loose sheath.
If you test marine rope and climbing and arborist rope for abrasion against rock, you will find climbing rope does MUCH better. The tight sheath is the reasons, just as webbing does better against chafe than marine rope. There are a few marine ropes with very tight covers for abrasion resistance (NER WRII comes to mind) and they are notoriously hard to splice.; most people just splice the core and call it good.
 
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