Ideas for designing a new kind of rope

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boatperson

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Hi all,

I've been given the task of designing a new rope for practical boat owners by my University.

I'm looking for specific clients needs (i.e soft, flexible, abrasion resistive) for a rope that would be suitable practical boat owners.

If I could make a rope for you what would you want it to do and what would it be for?

Any constructive feedback would be much appreciated

Thanks,
Dave
 
Loads of different rope specs. on every boat each tailored to one of a multitude of functions.
So if you are going to produce something new and completely innovative I would like a rope to replace anchor chain, strong, heavy but easy to handle and stow, massive strength, everlasting, easy to join securely to the anchor and good grip in the windlass and of course shock absorbing. Don't forget it also has to be affordable.
A much more sophisticated version of the current product which is basically a warp with weight woven in to it.

Talking about affordable, a cheap version of Dyneema with comparable strength and durability would also be attractive.
 
Hello boatperson

My deepest condolences, your supervisor has been unkind in the extreme.

Modern ropes have been developed over thousands of years and unless you can also invent a new material then there is no way you can design something new. However, my design requirements are:

Soft to handle;

Does not go hard under load;

Can be coiled easily;

Does not tangle easily; and the holy grail

Does not chafe

Cheers

Sandy
 
I've an idea. How about a rope that, instead of needing to be spliced to make a loop, could be joined to itself, maybe by heat or pressure.
A bit like self-amalgamating tape, perhaps.
 
Like many I tie up to a marina berth with 3 strand nylon warp. This has the key benefit of being stretchy, but is not ideal in other ways. A rope that addressed these would have a definite market.

Nylon warp, pros: stretchy, good breaking strain, reasonable wear/chafe resistance, can be (eye) spliced
Cons: takes up lots of space on a cleat, quite stiff (in terms of bending round short radii e.g. knots), rough on the hands (especially after years of use), heavy/bulky
 
That's an impossible brief. There's no such thing on a boat as all-purpose rope. Halyards have far different properties than anchor warps or mooring lines, for instance.
The most general property you might look at is resistance to chafe. There's no application on a boat where chafe is good. The rope would still have to be soft on the hands, though.
Stretch is required in some applications, e.g. anchor warps, but definitely not in others, e.g. halyards.
Strength is easily covered with modern materials.
Tangling is still a major issue, as you'll see if you spend an hour watching at any Marina. Ropes usually tangle because the way they're manufactured induces twist. If you could develop a method of manufacture that didn't involve twisting, you might become a millionaire very quickly.
Point of pedantry: there are no ropes on a boat. There are sheets, lines, halyards, warps and lanyards. Rope is the stuff you make these from.
Good luck.
 
StormNorm said:
That's an impossible brief. There's no such thing on a boat as all-purpose rope.
Click to expand...

Presumably that's why he asked "what would you want it to do and what would it be for".

Point of pedantry: there are no ropes on a boat. There are sheets, lines, halyards, warps and lanyards. Rope is the stuff you make these from.
Click to expand...

We've had this discussion quite recently, and the ultra-pedants insisted that the stuff is line. Or was it cord? It all seems rather silly to me, but I haven't time to worry because I have to check my bolt ropes.
 
StormNorm said:
Point of pedantry: there are no ropes on a boat. There are sheets, lines, halyards, warps and lanyards. Rope is the stuff you make these from.
Click to expand...
Slight correction there is one rope on a vessel, the bell rope. Don't all rush out to buy bells.
 
Sandy said:
Slight correction there is one rope on a vessel, the bell rope.
Click to expand...

Francis Herreshoff disagreed:

1. Awning-Rope, A rope around an area to which an awning is laced
2. Back-Rope The rope or pendant or small chain for staying the dolphin striker.
3. Bell-Rope A short rope attached to the tongue of a ships's bell.
4. Boat-Rope A separate rope veered to the boat to be towed at a ship's stern.
5. Bolt-Rope A hard laid rope used in several places whee it is not required to flex, such as the Head
Rope, Foot Rope, Leech Rope and Luff Rope of a sail.
6. Breast-Rope A rope fastened along the lanyards of the shrouds to secure the leadsman when in
the chains, heaving the lead.
7. Breech-Rope A rope to restrain the recoil of a gun when discharged.
8. Bucket-Rope A rope attached to the handle of a bucket for drawing water to scrub the deck, put
out fire, ect.
9. Bull-Rope A hawser rove through a block on the bowsprit and attached to a bouy to keep it clear
of the ship.
10. Bouy-Rope A rope that fastens the bout to the anchor.
11. Cat-Rope A line for hauling the cat-hook about.
12. Check-Rope A rope made fast to anything stationary for the purpose of bringing a moving vessel
to a stand.
13. Clew-Rope In large sails the eye or loop at the clew is made of a rope larger than the bolt rope
into which it is spliced.
14. Davit-Rope Lashing that secures the davit to the shroud when not in use.
15. Drag-Ropes Two ropes that are trailed from the after quarters of a sailing vessel so that if fell
overboard he could grab one of these ropes as the vessel passed him. They generally had Turk's
head knots on them, spaced about 21/2 feet apart, to assist in climbing aboard.
16. Entering Ropes(Man Ropes)jg Ropes that hung from the upper part of the stanchions alongside
of the ladder at the gangways.
17. Foot-Rope A rope suspended under a yard or boom for men to stand on. Also, that part of a
bolt to which the bottom of a sail is attached.
18. Grab-Rope A line secured above a boat boom or gangplank for steadying oneself.
19. Guest-Rope A rope fastened to an eye-bolt in the ships side, and to the outer end of a boom, .
projecting from the ship's side, by guys, to keep the boats clear off the sides.
20. Hawse-Rope A rope used to take the strain off the anchor warp when clearing hawse.
21. Head-Rope A rope to haul out jib-booms, and the bowsprits of cutters, etc. Also, that part of a
bolt rope at the top of a sail.
22. Heel-Rope A rope for securing the inner end of a studding-sail boom to a yard.
23. Jaw-Rope A rope over a jaw of a gaff to keep it from leaving the mast.
23. Limber-Rope A rope rove fore-and-aft throughout the limbers to clear them if necessary. ( Also a
light bronze chain was used for this purpose and known as a Limber-Chain)jg
24. Luff-Rope That part of a bolt rope on a fore-and-aft sail nearest the mast.
25. Parrel-Rope A rope used to confine a yard to a mast at its center.
26. Passing-Rope A rope led round the ship, through the eyes in the quarter, waist, gangway, and
forecastle stanchions forward to the knight's head.
27. Port-Ropes Ropes for the hauling up and suspending the gun port lids.
28. Ridge-Ropes Ropes sewed along the center of an awning to give it the pitch needed to shed rain.
29. Ring-Rope Ropes made fast to the ring-bolts in the deck, and by cross turns around the cable to
confine it in stormy weather, Also used to reeve off the anchor cable through the hawsehole.
30. Slip-Rope A rope whose bight is passed through the ring of a mooring bouy with both ends on
shipboard. By letting go one end and hauling on the other the ship is freed.
31. Span-Rope A rope made fast at both ends for hooking a block to the bight.
32. Spring-rope A rope led from a ships's quarter to her anchor cable, to bring her broadside guns to
bear upon a given object.
33. Swab-Rope A rope tied to the handle of a swab for dipping it overboard.
34. Tail-Rope A rope, attached to the clew cringle, that is made taut when the sheets are
transferred.
35. Tiller-Ropes Ropes leading from the tiller head round the barrel of the wheel. Also used to
secure and control the tiller of a small craft.
36. Top-Rope Rope rove throught the heel of a topmast to hist it by its tackle to the masthead.
37. Trip-Rope Rope fastened to the tripping hook of the anchor tackle to release the anchor when
the order, "Let fall!" is given.
37. Yard-Rope A temporary rope used for hoiting a yard for crossing or sending down.

(Shamelessly pinched from the Wooden Boat Forum: http://forum.woodenboat.com/showthread.php?212813-how-many-ropes)
 
I think your supervisor needs his/her head examining. It is a target which can only achieve two things: helping you learn about project management, and giving you some insights into materials science. You need to challenge and redefine the objectives and assumptions for a start.

Given the number of rope makers in the world, and the spend they must have on R&D, led by highly qualified technical specialists with years of experience in the trade, I think it highly unlikely that you will advance the sum of human knowledge in the subject. And that will disappoint you and not give a sense of achievement which will make a significant mark on your CV.

But, hey, if you want an impossible task...

A rope suitable for mooring sailing and motor yachts to buoys and pontoons.

It must:

1 be of a diameter which makes it easy to handle, min 14mm
2 have about 10% extensibility up to the specified safe working load, in elastic and visco-elastic mode
3 no plastic deformation
4 SG <1. ie it floats
5 UVA and B resistant
6 soft to handle and take round cleats
7 can be spliced easily using simple, readily available tools found on a boat (i.e does not need "setting" with tension after making)
8 intrinsically chafe resistant, or can be easily given a chafe-resistant covering
9 able to tolerate high temperatures typically found in tropical sunshine and when bent round a metal bollard
10 does not build up internal heat when under repeated surge load
11 resistant to chemicals such as antifouling, polishes, cleaners, fungi and algicides
12 has a thread which changes colour when the safe working load has been exceeded
13 non-fade coloration
14 will not support the growth of marine moulds, algae, weeds, etc yet is not environmentally toxic
 
Last edited:
boatperson said:
I've been given the task of designing a new rope for practical boat owners by my University.

I'm looking for specific clients needs (i.e soft, flexible, abrasion resistive) for a rope that would be suitable practical boat owners.

If I could make a rope for you what would you want it to do and what would it be for?
Click to expand...

Everyone wants the same basic properties from rope. They are:

* Strength (like Dyneema)
* Light weight (like Dyneema)
* not creeping (like wire rope)
* Abrasion resistant (like chain)
* Chemical resistant (like polyester)
* Heat stable (like wire rope)
* UV stable (like wire rope)
* Cheap (like polypropylene)
* Flexible, soft and pleasant to handle (like grandma's hand-knitted woolen socks)
* Non water absorbing and fast drying (like my polyester sweater)

The only properties we want to have options for are low stretch (halyards etc.) versus high stretch (snubbers, tow lines etc.) and floating (dinghy painters etc.) vs. sinking (anchor warp, etc.).

What did I forget? Oh yes, low friction. That's a tricky one - we generally want it, but it's bad for knots. We're mostly okay doing splices or learning fancy newfangled knots instead though.

The only reason we have all these different types of rope is because none of them do all of the above. Make a name for yourself by inventing one :encouragement:
 
Design a rope that does lose any strength in knots or splices. A stay clean surface would be useful and a low coefficient of friction.
 
boatperson said:
I've been given the task of designing a new rope for practical boat owners by my University.
Click to expand...

Sounds like a poisoned chalice. The existing options have been developed with a lot of work by people who fully understand the requirements.

What's your background? Are you looking at this from a technology point of view?

Ropes come in a variety of types because there is a big range of requirements.

1) Tying the boat up. In this case ropes are generally knows as warps. Nylon or polyester is generally used. Usually in three strand or octoplait construction. It's stretchy which eases the peak loads on cleats etc. It's also cheap, so not much of a market to break into. Maybe a mooring strop that provides the stretchiness but is immune to chaff.

2) Sheets and halyards etc.
a) Cruising boats is usually polyester braid on braid. Stretches a bit under load and lower breaking strain. Low reduction in strength in knots, around blocks, cleats etc as the fibre on the outside stretches so load is shared better across all fibres.
Although cheaper than b) or c) this has limitations. For example the sheets on my boat move up to half an inch at the clew of my headsail per wave/gust (with an effect on sail shape - hence performance and comfort - and wear and tear on the lines themselves and fittings). Which means I'll have to splash out on better ones soon.
b) Bigger cruisers or racers - dyneema or spectra. Low stretch, stronger. (You'll really need to understand the effect o stretch on optimum sail shape - good book in Trim by North Sails). Slippy - some knots & splices don't work well and can give way. Loses an awful lot of its strength in knots, around corners etc as the fibres on the outside of curves take all the strain.
See this for failure of these sorts of ropes on large ships. https://www.gov.uk/maib-reports/fai...board-lng-carrier-zarga-with-1-person-injured.
It's also pretty expensive for the average small boat owner.
c) cruising dyneema - a mixture of a) and b) to try to combine the advantages.

3) Very high strength very low stretch ropes. e.g. PBO - occasionally used to replace steel wires to hold up masts. If you could find a cost-effective replacement for steel wires (shrouds & stays) that lasts longer than the usual ten years (before stainless steel becomes unreliable due to fatigue) that would be a good one. You'd need something that insurance companies would stand over. You're unlikely to be the only one trying.

Maybe talk to one of the big rope manufacturers, e.g. English Braids. I suggest you'd need to gen up a lot on the technical side to support a conversation with one of their techies, if you can get it.
 
I'm not sure if this exists, but how about a braid on braid that IS actually stretchy, specifically for mooring lines? I use 3 strand and although it's quite a soft one (and so OK to handle) it's still 3 strand and prone to flip/kink as it exits the fairlead at a critical moment. It's also starting to harden at the normal cleating points. I'd like octoplait, but it's quite pricey and still quite 'big'. I suspect that half the reason that old sheets and halyards wrongly get used for mooring is the ease of handling. If you could make it float, so much the better.

Cue twenty posts telling me what it's called, where to buy it and why it's utterly useless.
 
I'd suggest a look around a few websites to understand the huge variety of rope already available.
AIUI, Steve Cockerill, of Rooster, more or less started his empire by creating a better rope for the Laser mainsheet. Less prone to tangles.
Something that is as good as the existing products for spinnaker sheets on a dinghy, but either doesn't require wearing gloves, or doesn't destroy several pairs a season might be nice.
 
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