cable laid vs rope (left vs right twist)

[davec]

Question on cable (left/s twist) vs rope (right/z twist): Much of the larger caliber line, particularly standing rigging, was cable laid.  Is this determined by size of the line or its use? As I start to make the line for my 1/48 Hannah, I’m trying to sort out which lines are cable laid and which are rope.  Are all lines over a certain diameter/circumference cable laid?

 

This would make sense as cable is made from rope, and it would seem hard to make large diameter line that is right twist (seems like it would need to be left twist, made from smaller right twist ropes). 

 

It would also be easier to model.  As all my source material is right twist (DMC Cordonett), I can use it off the spool for lines up to about 4” circumference (.025" scale diameter).  I have a Byrnes ropewalk, which does a nice job making left twist line from right twist material, and which I could make cable laid line for anything above .025" diameter.  It doesn’t do so well making right twist line from right twist thread.  It will unwind the strands, then rewind in the opposite direction, but is very finicky and hard to keep even.  If I can use left twist for everything above 4” circumference, I am set.

 

Thoughts?

 

Thanks!
 

Dave

 

 

[Modeler12]

Dave, I have used the same cotton thread for most of my rigging. But I also have made 'rope' up to .040 inch thickness going the 'wrong' direction (it is S not Z). It takes close scrutiny to see the difference at scale level, so I went ahead and used it for the big stays and shrouds.

Another possibility is to use polyester sewing thread and make rope out of that and then the cable. I have made rope with some that was only 0.008 inch diameter to start with.

[Jim Lad]

Dave,

 

I'm not sure just how large a hawser laid rope can be - when I was at sea we used to use 10 inch mooring lines that were hawser laid (just don't be in the way if one breaks under strain).  Cable laid rope was indeed made by laying up three hawser laid ropes, which is why it was laid up left handed.

 

The lower stays and shrouds of hemp rigged vessels were commonly (but not universally) of cable laid rope, and so left handed.  On small ships the lower rigging was sometimes hawser laid.

 

I'm speaking here of English 19th century practice, by the way.

 

John

[BANYAN]

Hi Davec, I think you are on the right track.  Druxey or another more knowledgable member may be able to provide more info.  My understanding is that LH (Cable) was stronger and had less flexibility.  As most standing rigging did not need much adjustment/working LH was perfect as it also lent strength to these important ropes.  Where flexibility was needed, and to some degree less tensile strength, RH was the go.

 

cheers

 

Pat

[Modeler12]

Hi Davec, I think you are on the right track.  Druxey or another more knowledgable member may be able to provide more info.  My understanding is that LH (Cable) was stronger and had less flexibility.  As most standing rigging did not need much adjustment/working LH was perfect as it also lent strength to these important ropes.  Where flexibility was needed, and to some degree less tensile strength, RH was the go.

 

cheers

 

Pat

I am sorry Pat, but this reasoning is not correct.

 

The tensile strength of a rope, or any other form, is dependent on the tensile strength of the material. When it is twisted it will affect the overall strength, but the direction in which is twisted has no bearing on that.

If the material is twisted into a 'yarn' to start with, and if that should be twisted in the clockwise direction, then that should not be made into a rope that is also in the clockwise direction. The result could be disastrous as shown below when I tried that for 'fun'.

Flexibility is not achieved by going that route. But perhaps I misunderstood your reply.

[davec]

Jim, Pat and Jay,

 

Thanks for your comments.  Hannah was early 1770’s American, so I think it is safe to assume it followed English 19^th century practice.  I have spent a while researching the rigging, and haven’t come across anything that said practices were different in the colonies.

 

I’m trying to use cotton throughout except for silk for the serving.  I used synthetics in the past (particularly morope) and had difficulty having it keep shape for coils.  I also want to be able to dye it myself.  So far my experiments with 4-0 silk and white dmc cordonet crochet thread have worked out well in terms of coloring – the different diameter crochet threads and the silk all end up the same color with the stain.

 

I got the rope walk so I could get the color, size, and twist all correct.  The only rigging that is over 4” circumference is standing rigging – shrouds and stays, so if it would be historically consistent to use left twist on the medium and larger diameter lines, it would make life a lot easier.

 

I suspect the difference in strength that Pat was talking about may relate to the alternating direction of the strands in cable laid vs same direction in hawser laid- the difference is more than just left vs right twist.    It would definitely change flexibility.  I won’t use cable laid for any running rigging.

 

Dave

[JerseyCity Frankie]

Congratulations on even CARING about the lay of the  rope. I think more modelers should pay attention to that sort of detail. I know that when you start down that road of looking for the proper rigging you open a pandora's box but clearly worrying about the line you use makes you a better model builder. Every garage sale I visit I have my eye out for thread or string. It appears that there were more options for threads of different diameters in days gone by than there are today and finding a box of old thread is always fun, but you have to make sure the stuff is reasonably sound. I prefer to use an existing thread but I do have a home made rope walk and turn to that when I need it. I have never had great success trying to remove the lay from some material in order to lay it up in the opposite direction though, I can do it to some extent but its a messy process with a lot of hockles.

[michael mott]

I went back into the vaults here on the forum because I just realized that I had been making z lay or left hand rope and revisiting some close ups of some of the cutters rigging discovered most of the lines are right hand or s laid. After rereading the comments again in this thread about ropes unraveling I still had to sit and do some little drawings showing the mechanics of which way things were twisting and whirling to fully understand Chucks comments about equal and opposing forces in the ropes, I think that the light bulb just went on in my head, and the comments about the feel of the tension is something that I am also beginning to understand.

 

Every day I learn something new about this wonderful hobby and it really is remarkable how much sharing goes on here and what a wealth of knowledge there is by the membership.

 

This is all very important to me because my ropes and rigging are working and not static. For me I need to understand the whys and wherefores of what I am making, even when my experimenting leads me to the wrong conclusions. I then understand why its the wrong one.

 

So back to some more twisting, I discovered it takes 3 x 21 strands of ne50 Guttmann cotton to make 3/4 inch rope in 1:8 scale.

 

Michael

Edited February 21, 2014 by michael mott

[michael mott]

So after some more twisting I made a few feet of some .045 rope which is using 9 strands of Guttmann 50ne 100% cotton and 25 feet of .093 which is 3/4 inch diameter in 1:8 scale it took 3x21 strands. and I walked 1575 feet to string up the tools, for just this one rope, and calculating the 1/2 inch ropes it all ads up to 4950 feet that is almost a mile. Who would have thought this modelmaking hobby would provide exercise as well?

 

 

I think it looks pretty close, it will do for this model.

 

 

And the equipment.

 

 

Michael

 

 

 

 

[oneslim]

Michael,

 

I think You have the 'S' and 'Z' twist thing backwards.  'S' twist is to the left, because the center stroke of the 'S' slants up to the left.  'Z' twist is to the right as the center stroke slants up to the right.

 

Hope This Helps

 

Bob W

[Gaetan Bordeleau]

Michael, I do not see how you can make rope with the drill on the picture in front of the ML7?

[michael mott]

Bob yes you are correct I got the names backwards.

 

Gaetan the way it works is that the threads are stretched between the aluminum whirls and the disc in the drill which is set up facing the whirls 25 feet away

 

The whirl end is rotated while the end in the drill is fixed until the threads are twisted up when I have twisted them enough (this is the part where I am still learning the feel of the tension) I stop twisting and go the the drill and start it revolving in the opposite direction of the twisted threads and the rope immediately begins forming at the midpoint between the whirls and the disk with the three hooks after running the drill for long enough for the rope forming to reach the drill  then I stop and unhook everything that is all there is to it. I will take some pictures tomorrow of the way it works for me.

 

Michael

[michael mott]

The following sequence shows the way I have made the rope Gaetan.

whirl end with threads twisted I added the arrows to remind myself of the correct turn

spinner end ready to rotate

The beginning of the rotation of the spinner end

Notice the three twisted lines at the centre of the span

The rope unhooked at the spinner end

the finished spin at the whirl end

The cut rope on the bottom is the same rope that was used for the original test that was laid up left handed and too loose the bottom rope was unwound and rewound using the drill and resetting for the right hand lay,  the bottom rope is still not perfect as it is unraveling a little so the equal tension is not quite right yet

the two coils of rope to show the progression of the method that I am getting a little better at.

 

Michael

 

 

[Chuck]

Looking at your rope I would recommend doubling your initial twists and then doing the same with the twisting of the three strands together.

 

Chuck

[michael mott]

Thank you again for your council Chuck.

 

Michael

[michael mott]

following your advice Chuck I have unwound and rewound the loose rope on the right both of these ropes have the same number of strands the rewound one is now also smaller in diameter and there was very little unravelling

 

 

and it looks much better.

 

michael

Edited February 21, 2014 by michael mott

[Gaetan Bordeleau]

Michael, your method to produce cable is 50% right,  at one end the method is good but at the end with the drill, the method you use cannot produce good quality cable.

The method to turn ropes is as in picture 2.

The method you use is as in picture one.

Your friend at the end with the drill keeps the tension but it is very difficult to keep a very steady tension, it would be better if it would be mechanical.

 

In picture 3, tension is kept regular by weight.

Also there is a swivel where the ropes end.  This swivel acts as a tension regulator.

The tension in the ropes decide when to join together, it is not you who is suppose to decide when to bjoin the 3 ropes together. 

[jud]

Have been looking at various rope walks and how they were traditionally constructed and used. I have the room so my preference is to build one with a swivel on the tail stock and use a topper to control the final twist. A two way motor with a long cable control switch box would be handy to increase or decrease the thread twist as the rope was forming, just a short distance should be enough to fine tune the initial twist. Ropes were formed from the tail stock behind the topper on those types of rope walks, they do require a long narrow space.

jud

 

PS: kind of interesting to read about the different ways ropes were made for different uses such as the shroud lay, 4 threads formed over a core. That center core would require provisions on both ends for it to be at center and not be twisted while forming the rope, A small wire core, might eliminate sagging rigging.

Edited February 21, 2014 by jud

[Chuck]

Yes it did get smaller but its a much better rope.   That will happen.   If it still unravels its because your using multiple lines on each and twisting them first.   Those wont stay twisted because you never twisted them individually first to create tension.  That being said,   it will still hold together well enough.  For example,  when I make a larger cable I first make three smaller cables with tension so they wont unwind.  Then I take those three and make the larger rope.   You end up with an opposite twist however so you have to remember to correct that by creating the first three strand with the opposite twist you will eventually require.

 

I do understand what Gaetan is saying though.   Standing while twisting is very awkward.  Better if that end is on a table top as is mine.  Then you are able to control the "walking" of that end better.   You will also get a better "feel" for that tension.  I am sure his more complex rope walk works great as well.  But like I said....simple is just as good.   I dont use any weights at all and I simply slide the end on a table and "feel the tension".  I can adjust if needed.

 

 

It will be difficult to achieve the same results over and over again without that sort of control.  Standing up like that will make it very hard to replicate over and over again.

 

Chuck

[Gaetan Bordeleau]

Chuck I cannot comment your method, I did not see your machine. 

You say you never twist lines individually first to create tension.

The problem with Michael is that he turns all the lines together.

The strength that makes ropes to form together is not the tension but more a torsion and the magic is in this torsion strength.

This torsion must be built individually in each rope. Then the interlacing of the 3 ropes make a cable.

  

When I said Standing while twisting is very awkward, I was commenting Michael picture where we see this friend holding a drill. As for tension, weights create a stable pressure and the 4 wheels buggy compensate for the diminution of the length. All these factors produce a very stable cable which does not need any corrections.

[dafi]

Coming back to the original question:

 

If my memory serves me well, from a circumference of 9 inch it was cable laid (left/s twist). Thinner cable laid ropes were called cablets in my understanding.

 

Steel, 54:

 

CABLES, ropes made of nine strands, that are nine inches and upwards in circumference.

CABLETS, cable-laid ropes, under nine inches in circumference.

 

XXXDan

Edited February 22, 2014 by dafi

[michael mott]

Dan if my understanding is correct then the 9 strands would be formed from three strands and then the three are wound again to form the cable, which is similar to what Chuck describes for the heavier rope/cable

 

 

When I said Standing while twisting is very awkward, I was commenting Michael picture where we see this friend holding a drill. As for tension, weights create a stable pressure and the 4 wheels buggy compensate for the diminution of the length. All these factors produce a very stable cable which does not need any corrections.

Gaetan just to clarify one point the friend in the picture is me and I can feel the tension on the lines which were twisted with a fair bit of initial twist in each strand I felt the tension in the same way one checks the tension in ta bandsaw blade when one does not have a tension tool gauge. it doesn't show but I am putting a fair bit of pull on the drill to maintain the tension admittedly this is not the same as a set mechanical weight. I have used similar set up to the one you have shown, I prefer this method because of its simplicity and my body is a good way to feel the tension.

 

For rope that is only 50% correct I am pretty satisfied with how it looks for my model regardless of the technicalities of construction.

 

 

As you can see the loose cut end looks reasonably stable.

 

 

 

I do understand what Gaetan is saying though.   Standing while twisting is very awkward.  Better if that end is on a table top as is mine.  Then you are able to control the "walking" of that end better.   You will also get a better "feel" for that tension.  I am sure his more complex rope walk works great as well.  But like I said....simple is just as good.   I dont use any weights at all and I simply slide the end on a table and "feel the tension".  I can adjust if needed.

 

 

It will be difficult to achieve the same results over and over again without that sort of control.  Standing up like that will make it very hard to replicate over and over again.

 

 

I agree that to achieve absolutely consistent results a consistent set up is required. These smaller 1/2 inch scale ropes were made by having the drill with the spinner get pulled across a table for 36 inches a crude measure for sure but a consistent set up each time.

 

It would also be good to have a revolution counter to ensure equal and opposite numbers of twists but as a friend once quoted to me "I am not building a Piano" so using my own senses and the value of practical experience  I think that I will be able to get reasonably consistent results of making Cable and Rope in right or left hand twist as the following picture again shows improvement on the 1/2 inch scale rope with the correct twist.

 

 

Not much unraveling on the loose cut ends.

 

Michael

Edited February 23, 2014 by michael mott

[jwa]

This is still a confusing subject for me - which type of rope is used in various circumstances.  I had thought that left-handed 'S' rope was used for most applications.  Right-handed 'Z' rope is used for the heavier anchor cables and stays.  But in reading through the topics, there seems to be confusion in identifying and labeling the the two types - but, then again, I am easily confused!.  I believe Chuck's material is an example of left-handed 'S' rope which would be used for all running rigging and some of the smaller sized standing rigging.  Is this correct?

 

Also,  if I am reading Chuck's description correctly, in making larger cables from previously made rope, if you want a right-hand 'Z' cable, you twist three left-hand 'S' ropes.  Does this mean you go through the process of putting the initial twist - for tension - on the individual strands and then twist them to lay up a left-hand rope.  Once you have made three left-hand ropes, you then twist these to achieve the right-hand cable.  Do you have to tension the laid-up left-hand rope in the opposite direction before you twist them into the right-hand cable?  It makes sense since you have to equalize the tension for the cable to be stable.  But then this completely undoes what you previously made and does not appear that it would have any affect on the original individual strands - you would end up with a kinked up mess.  Or do you simply take the left-hand rope and, without any additional tension applied, twist them in the appropriate direction to achieve the right-hand cable?  

 

It is probably very obvious and I am reading too much into it.  

 

Thanks,
Jerry

[BANYAN]

Hi Jerry, actually it is the other way around -LH lay (S) lays up much stiffer and provides more strength and was generally used in standing rigging where strength was required (such as shrouds stays etc).  However, it is not a hard and fast rule that LH lay rope was always used for shrouds etc; sometimes, shroud lay (4 strand) was used etc.  RH lay being more flexible was generally used for running rigging.

 

cheers

 

Pat

[Chuck]

Jerry...you asked

 

Once you have made three left-hand ropes, you then twist these to achieve the right-hand cable.  Do you have to tension the laid-up left-hand rope in the opposite direction before you twist them into the right-hand cable? 

 

The answer is yes...Twist them even more to create a tight twist that will want to untwist when you are done.  This "wanting to untwist"  creates the tension when you wind all three in opposite direction afterwards.   Its the same as when you started with the smaller ropes....You must twist the individual strands first...otherwise they have no tension.....which will soon be equalized when you twist all three together in the opposite direction.  You see,  when folks just place 9 strands on a rope walk (3 on each without having turned them into rope first) and just do the initial twist of the nine.....there was no tension to keep those initial twisted three threads together as rope.    In fact,  if this is what you have tried as Michael has.....try this experiment.

 

Before you twist those nine strands into rope after completing the initial twists...just cut them free and see what happens to them.  You will soon find that they quickly unwind.   This doesnt create a good large cable because it will always want to unwind from its core...

 

Yes it saves time, but it doesnt make the best rope.  This will happen on any machine or ropewalk.  It usually starts on the ends that were cut, even with a sharp blade.   The three larger ropes untwist just a little bit......then the individual strands in each of those that were not laid up properly begin to untwist...then it just creeps along the whole length of rope in short order as you handle the ends with your hands.   

 

Hope that makes sense.  Its much easier to show a person while they are in my shop than explain it in writing.

 

Chuck

[jwa]

Thanks Pat and Chuck.  My experiments with rope making result in good looking rope, but they do want to unravel somewhat.  I'll try more tension to see if that solves that issue.  

[captainbob]

Let me add to the confusion. This is from a dictionary. “Common twisted rope generally consists of three strands and is normally right-laid, or given a final right-handed twist.

The ISO 2 standard uses the uppercase letters S and Z to indicate the two possible directions of twist, as suggested by the direction of slant of the central portions of these two letters. The handedness of the twist is the direction of the twists as they progress away from an observer. Thus Z-twist rope is said to be right-handed, and S-twist to be left-handed.”

 

 

The strength of a rope has to do with how parallel the strands are with the length of the rope and has nothing to do with which way it is twisted. 

 

Bob

[pompey2]

Nice explaination, thanks Bob

[SJSoane]

Reading Steele's Masting and Rigging tables, he identifies certain specific lines as "cable laid". This includes large stays, but also sheets and tacks. So it is not necessarily specific to standing or running rigging. Would "cable laid" in Steele's tables be the S direction as Bob explains so well above?

 

Mark

 

 

[popeye2sea]

3 hours ago, SJSoane said:

Reading Steele's Masting and Rigging tables, he identifies certain specific lines as "cable laid". This includes large stays, but also sheets and tacks. So it is not necessarily specific to standing or running rigging. Would "cable laid" in Steele's tables be the S direction as Bob explains so well above?

 

Mark

 

 

Yes