Pre-stretched Polyester Ropes - Revision history

TonyL: \added Dyneema\

2012-08-18T20:44:45Z

\added Dyneema\

Itsabubble: /* Marlow Rope Specifications */

2008-12-12T23:34:10Z

Marlow Rope Specifications

Itsabubble: /* Marlow Rope Specifications */

2008-12-12T23:30:56Z

Marlow Rope Specifications

Itsabubble: /* Marlow Rope Specifications */

2008-12-12T23:05:38Z

Marlow Rope Specifications

Itsabubble: /* Marlow Rope Specifications */

2008-12-12T22:59:14Z

Marlow Rope Specifications

GACJ: Added to Bells and Fittings category

2008-08-13T09:46:46Z

Added to Bells and Fittings category

Adamsc: Updated formatting

2008-08-10T14:23:49Z

Updated formatting

Adamsc at 10:00, 8 August 2008

2008-08-08T10:00:48Z

Adamsc at 09:47, 8 August 2008

2008-08-08T09:47:21Z

Adamsc: New page: !!Pre-stretched polyester ropes. (Based on a thread on Change-Ringers, May 2005, summarising contributions from John Harrison, Matthew Higby and Philip Pratt). Pre-stretched polyester is...

2008-08-08T09:42:42Z

New page: !!Pre-stretched polyester ropes. (Based on a thread on Change-Ringers, May 2005, summarising contributions from John Harrison, Matthew Higby and Philip Pratt). Pre-stretched polyester is...

New page

!!Pre-stretched polyester ropes.

(Based on a thread on Change-Ringers, May 2005, summarising contributions from John Harrison, Matthew Higby and Philip Pratt).

Pre-stretched polyester is similar to 'Terylene' which is a commercial brand-name. It is a good material for the top end of bell ropes because:

* it does not shrink in damp weather

* it does not go stiff in damp weather

* it is not springy when new

* it lasts almost indefinitely

Two manufacturers supply products which have been used in towers, Marlow and English Braids. The Marlow rope has orange and black tracers in the rope, while the one from English Braids has blue. Marlow rope has been found to be less springy and is preferred by most users.

!Marlow Rope Specifications

Users of Marlow rope have suffered some confusion as the specification has changed at times. A military specification rope, with far less stretch, has similar colour markings to the sailing grade. The sailing grade rope in 10mm diameter is suitable for short ropes (up to about 8m), but displays more spring on long draughts. Upgrading to 12mm diameter is recommended in this case.

The part number is important, because the MOD/navy spec rope has a different part starting with AE not AC. The AC type is the sailing rope, whereas the AE is the MOD spec version. To obtain a copy of the technical specification of this rope you will need to contact the MOD, because Marlow are not allowed to release any details of this rope without consent of the MOD, if at all. The technical specification for the AC sailing type of rope is available from Marlow in
the form of a PDF file.

According to to the technical branch of Marlow Ropes there is no theoretical difference between the two types in terms of their stretch characteristics. The identifiable difference between the ropes is a slight change in colour of the red/orange fleck. AC has a burnt red fleck, and AE has a distinct orange. The AE type of rope is produced to what they call 'British Standard' and is overspec'd in its load characteristics (and is a little larger in diameter), to guarantee that the rope will be consistent from reel to reel, and will not break below a certain load. The heat treatment process is also probably a lot more consistent and thorough; the details of this are apparently contained within the MOD technical specification sheet, which they are not able to release.

The 10mm AC type of rope has a breaking load of over 2300kg (it could singly carry the dead weight of up to a 46cwt bell) which, in terms of its use in bell ringing, is not remotely approached.

Since ringing never reaches more than 5\% of the break load of the rope, and there may still be stretch (typically 1\% extension which makes a huge difference) we should look at increasing the spec of the rope to either 12 or 14mm diameter so we never get above say 2 or 3 \% of its total break load and thus 0.5\% or less stretch.

!Splicing

Pre-stretched polyester rope can be short-spliced by hand and can also be machine spliced. Theoretically (because of the differing coefficients of friction) it should not be long-spliced with natural fibre rope, but there are several reports of this being achieved successfully in practice.

<i>David Beacham writes:</i> I have had no trouble at all with joining polyester to flax with a conventional long splice, which you need to do if some part of the rope passes over an intermediate pulley. (If you use a short splice in this situation, you will feel the "bump" as the splice runs over the pulley.)

<i>Mark Davies writes:</i> I agree with David, I've long-spliced flax to poly without problems, and the splices have lasted many years. When tucking the ends in, you can't "comb out" polyester so well as natural yarn, since the fibres don't come loose. However, you should still use the comb, and tuck in as usual as best you can. If you like, you can trim half the ends of each poly strand in order to get a neater result. On NO ACCOUNT should you heat-seal the ends of the poly strands, as this will not only look unsightly, but also cause the spliced-in natural rope to wear quickly due to friction with the sharp ends of the heated-sealed polyester. Don't even think about it!

!Fitting Polyester Ropes

Remember that you do not need to have yards of "spare" rope wound around the spokes. To do so is a waste of money. About three times round would do. If you wish to have more, extend the rope by tying some old rope onto it.

Natural fibre rope should always be used below the sally.

@@ Line 35: / Line 35: @@
 ==Acknowledgement==
-This page is based on a thread on Change-Ringers, May 2005, and summarises contributions from John Harrison, Matthew Higby and Philip Pratt.
+The above page is based on a thread on Change-Ringers, May 2005, and summarises contributions from John Harrison, Matthew Higby and Philip Pratt.
 [[Category:Bells and Fittings]]

@@ Line 10: / Line 10: @@
 ==Marlow Rope Specifications==
-Users of Marlow rope have suffered some confusion as the specification has changed at times. A military (MOD) specification rope, has been available in the past with similar colour markings to the sailing grade.  This has been 'spun as a yarn' down the pub by many ringers, to suggest that it is a far better rope for bell ropes. There have been a few other manufacturers of pre-stretched polyester who have used the same colour identifying markers that Marlow use but have not made them to the same exacting standards.
+Users of Marlow rope have suffered some confusion as the specification has changed at times. A military (MOD) specification rope, has been available in the past with similar colour markings to the sailing grade.  This has been 'spun as a yarn' down the pub by many ringers, to suggest that it is a far better rope for bell ropes. There have been a few other manufacturers who have copied Marlows pre-stretched polyester and laid in the same colour identifying markers that Marlow use but have not made them to the same exacting [high] standards.
 Batches of pre-stretched polyester top ends have been supplied by Pritchards ropemakers of Loughborough during their last 5 or so years, utilising a yellow or grey fleck. In many towers these yellow flecked top ends have proved un-satisfactory.

@@ Line 10: / Line 10: @@
 ==Marlow Rope Specifications==
-Users of Marlow rope have suffered some confusion as the specification has changed at times. A military specification rope, with far less stretch, has similar colour markings to the sailing grade. The sailing grade rope in 10mm diameter is suitable for short ropes (up to about 8m), but displays more spring on long draughts. Upgrading to 12mm diameter would be recommended.
+Users of Marlow rope have suffered some confusion as the specification has changed at times. A military (MOD) specification rope, has been available in the past with similar colour markings to the sailing grade.  This has been 'spun as a yarn' down the pub by many ringers, to suggest that it is a far better rope for bell ropes. There have been a few other manufacturers of pre-stretched polyester who have used the same colour identifying markers that Marlow use but have not made them to the same exacting standards.
-It would appear that the MOD specification almost identical to the sailing grade except there is a change in the coloured marker arrangement; rather than two markers it is a single orange/black fleck. The technical specification for the sailing type of rope is available from Marlow's website in the form of a PDF file.
+Batches of pre-stretched polyester top ends have been supplied by Pritchards ropemakers of Loughborough during their last 5 or so years, utilising a yellow or grey fleck. In many towers these yellow flecked top ends have proved un-satisfactory.
-The  10mm sailing type of rope has a breaking load of over 2300kg (it could singly carry the dead weight of up to a 46cwt bell) which, in terms of its use in bell ringing, is not remotely approached.
+The pre-stretched polyester rope supplied to the bell rope makers is tailor made in very large batches to their own specification and does exhibit properties making it more suited to the application of bell ringing than the standard sailing grade, and in particular the stretch tolerance allowed.
-Since ringing never reaches more than 5% of the break load of the rope, and there may still be stretch (typically 1% extension which makes a huge difference) we should look at increasing the diameter of the rope to 12mm diameter to reduce the loading to say 2% or 3% of its total break load and thus the stretch to 0.5% or less.
+The sailing grade rope in 10mm diameter should be suitable for most ropes (up to about 8m), but displays more spring on long draughts. Upgrading to 12mm diameter would be recommended.
 ==Splicing==

@@ Line 10: / Line 10: @@
 ==Marlow Rope Specifications==
-Users of Marlow rope have suffered some confusion as the specification has changed at times. A military specification rope, with far less stretch, has similar colour markings to the sailing grade. The sailing grade rope in 10mm diameter is suitable for short ropes (up to about 8m), but displays more spring on long draughts. Upgrading to 12mm diameter is recommended in this case.
+Users of Marlow rope have suffered some confusion as the specification has changed at times. A military specification rope, with far less stretch, has similar colour markings to the sailing grade. The sailing grade rope in 10mm diameter is suitable for short ropes (up to about 8m), but displays more spring on long draughts. Upgrading to 12mm diameter would be recommended.
-The part number is important, because the MOD/navy spec rope has a different part starting with AE not AC. The AC type is the sailing rope, whereas the AE is the MOD spec version. It would appear that the MOD specification differs from the sailing grade by a change in the coloured marker arrangement; rather than two markers it is a single orange/black fleck. The technical specification for the AC sailing type of rope is available from Marlow's website in the form of a PDF file.
+It would appear that the MOD specification almost identical to the sailing grade except there is a change in the coloured marker arrangement; rather than two markers it is a single orange/black fleck. The technical specification for the sailing type of rope is available from Marlow's website in the form of a PDF file.
-The  10mm AC type of rope has a breaking load of over 2300kg (it could singly carry the dead weight of up to a 46cwt bell) which, in terms of its use in bell ringing, is not remotely approached.
+The  10mm sailing type of rope has a breaking load of over 2300kg (it could singly carry the dead weight of up to a 46cwt bell) which, in terms of its use in bell ringing, is not remotely approached.
-Since ringing never reaches more than 5% of the break load of the rope, and there may still be stretch (typically 1% extension which makes a huge difference) we should look at increasing the spec of the rope to either 12 or 14mm diameter so we never get above say 2% or 3% of its total break load and thus 0.5% or less stretch.
+Since ringing never reaches more than 5% of the break load of the rope, and there may still be stretch (typically 1% extension which makes a huge difference) we should look at increasing the diameter of the rope to 12mm diameter to reduce the loading to say 2% or 3% of its total break load and thus the stretch to 0.5% or less.
 ==Splicing==

← Older revision		Revision as of 09:46, 13 August 2008
Line 35:		Line 35:
	==Acknowledgement==		==Acknowledgement==
	This page is based on a thread on Change-Ringers, May 2005, and summarises contributions from John Harrison, Matthew Higby and Philip Pratt.		This page is based on a thread on Change-Ringers, May 2005, and summarises contributions from John Harrison, Matthew Higby and Philip Pratt.
		+	[[Category:Bells and Fittings]]

@@ Line 1: / Line 1: @@
 __NOTOC__
 Pre-stretched polyester is similar to 'Terylene' which is a commercial brand-name. It is a good material for the top end of bell ropes because:
@@ Line 10: / Line 9: @@
 Two manufacturers supply products which have been used in towers, Marlow and English Braids. The Marlow rope has orange and black tracers in the rope, while the one from English Braids has blue. Marlow rope has been found to be less springy and is preferred by most users.
-===Marlow Rope Specifications===
+==Marlow Rope Specifications==
 Users of Marlow rope have suffered some confusion as the specification has changed at times. A military specification rope, with far less stretch, has similar colour markings to the sailing grade. The sailing grade rope in 10mm diameter is suitable for short ropes (up to about 8m), but displays more spring on long draughts. Upgrading to 12mm diameter is recommended in this case.
@@ Line 22: / Line 21: @@
 Since ringing never reaches more than 5% of the break load of the rope, and there may still be stretch (typically 1% extension which makes a huge difference) we should look at increasing the spec of the rope to either 12 or 14mm diameter so we never get above say 2% or 3% of its total break load and thus 0.5% or less stretch.
-===Splicing===
+==Splicing==
 Pre-stretched polyester rope can be short-spliced by hand and can also be machine spliced. Theoretically (because of the differing coefficients of friction) it should not be long-spliced with natural fibre rope, but there are several reports of this being achieved successfully in practice.
@@ Line 29: / Line 28: @@
 <i>Mark Davies writes:</i> I agree with David, I've long-spliced flax to poly without problems, and the splices have lasted many years. When tucking the ends in, you can't "comb out" polyester so well as natural yarn, since the fibres don't come loose. However, you should still use the comb, and tuck in as usual as best you can. If you like, you can trim half the ends of each poly strand in order to get a neater result. On NO ACCOUNT should you heat-seal the ends of the poly strands, as this will not only look unsightly, but also cause the spliced-in natural rope to wear quickly due to friction with the sharp ends of the heated-sealed polyester. Don't even think about it!
-===Fitting Polyester Ropes===
+==Fitting Polyester Ropes==
 Remember that you do not need to have yards of "spare" rope wound around the spokes. To do so is a waste of money. About three times round would do. If you wish to have more, extend the rope by tying some old rope onto it.
 Natural fibre rope should always be used below the sally.
-===Acknowledgement===
+==Acknowledgement==
 This page is based on a thread on Change-Ringers, May 2005, and summarises contributions from John Harrison, Matthew Higby and Philip Pratt.