Handbook of Fibre Rope Technology

H A McKenna, J. W. S. Hearle, N O'Hear

• Publisher: Woodhead Publishing
• Year: 2004
• Print ISBN: 9781855736061
• eBook ISBN: 9781855739932
• Topic: Technology & Engineering
• Subtopic: Materials Science
• Index: Technology & Engineering

The field of fibre rope technology has witnessed incredible change and technological advance over the last few decades. At the forefront of this change has been the development of synthetic fibres and modern types of rope construction. This handbook updates the history and structural mechanics of fibre rope technology and describes the types and properties of modern rope-making materials and constructions.Following an introduction to fibre ropes, the Handbook of fibre rope technology takes a comprehensive look at rope-making materials, rope structures, properties and mechanics and covers rope production, focusing on laid strand, braided, low-twist and parallel yarn ropes. Terminations are also introduced and the many uses of rope are illustrated. The key issues surrounding the inspection and retirement of rope are identified and rope testing is thoroughly examined. The final two chapters review rope markets, distribution and liability and provide case studies from the many environments in which fibre rope is used.The Handbook of fibre rope technology is an essential reference for everyone assisting in the design, selection, use, inspection and testing of fibre rope.- A comprehensive look at rope-making materials and structures, properties and mechanics- Covers rope production including laid strand, braided, low-twist and parallel yarn ropes and rope terminations- Rope testing is examined in depth, as well as the key issues surrounding rope retirement

1

Introduction to fibre ropes

1.1 Ropes from ancient times to the mid-twentieth century

1.1.1 Prehistory and history

In a sense, some animals were the first to use ropes. They used the long strands of vines and other plants to climb trees and swing from one branch to another. These ‘ropes’ are oriented assemblies of strong fibres in a softer matrix, not unlike modern pultruded composites. However, the real start of the story is the invention of manufactured ropes.

Probably at different times in different parts of the world, but always before recorded history, men and women discovered that they could take fibres or coarser strands found in nature, twist them together to make long, strong yarns, and then twist the yarns together to make thicker ropes. Ropes are one of the oldest human artefacts. Gilbert (1954) notes that ‘a cave-painting [Fig. 1.1] in eastern Spain of Late Palaeolithic or Mesolithic date depicts a person using what appear to be ropes to climb down the face of a cliff, in order to collect wild honey’. Doubtless, ropes were made earlier in the history of mankind. However, these organic materials decay easily, unlike rock-cut drawings, stone tools, metalwork, pottery or the buildings of ancient civilisations. Natural fibre ropes only survive in water-logged or very dry conditions. Few artefacts remain. One of the earliest examples of artificial cordage is a piece of a fishing net made 10 000 years ago in Mesolithic (Middle Stone Age) times and found by archaeologists in Finland (Gilbert, 1954).

Fig. 1.1 Cave painting from eastern Spain, showing honey gatherer climbing ropes up a cliff face. From Oakley (1950) after Obermaier.

One large rope, shown in Fig. 1.2, dates from 2500 years ago. In 1942, some British troops taking time off from the war, explored the Tura Caves on the banks of the Nile. They found blocks of stone similar to those used in the pyramids, and round one of these was a rope made of papyrus in about 500 BC. The hierarchical structure was similar to a modern three-strand rope: seven fibres were twisted in the cross-sections of the yarns, 40 yarns were twisted into strands, and 3 strands were twisted together to form the rope. By a lucky coincidence, G.C. Hawkins, grandson of the founder of Hawkins and Tipson, ropemakers of Sussex in the South of England (now, as Marlow Ropes, the largest UK rope manufacturer) was an officer with the South African forces in Egypt and was given a piece of the rope.

Fig. 1.2 A papyrus rope made in 500 BC. From Tyson (1966).

More information can be obtained from the pictorial and written record. A picture of an Egyptian reed boat from 2400 BC shows ropes holding up the sails. From circa 700 BC, the excavations of Nineveh in Mesopotamia (modern Iraq) by Layard in the nineteenth century uncovered many pictures of colossi being pulled along by ropes. The drawing of a bas-relief, Fig. 1.3(a), from the Palace of Sennacherib shows a huge statue of a bull being pulled along by scores of men using ropes as thick as a human wrist. The stranded construction of the rope can be clearly seen, Fig. 1.3(b).

Fig. 1.3 (a) A bull colossus being pulled along by ropes, circa 700 BC; bas-relief from the Palace at Sennacherib in Nineveh. From a drawing made on the spot by A.H. Layard, during his second expedition to Assyria. From Layard (1853). (b) Detail of the ropes. Reproduced by courtesy of the Director and Librarian, the John Rylands University Library of Manchester, England.

As Gilbert (1954) wrote in Volume 1 of the OUP History of Technology ‘The manufacture of ropes was of the greatest importance in the ancient empires, for man was the chief source of motive power, and it was only by means of ropes that the gangs of slaves could apply their combined strengths to move the huge stones used in the construction of the pyramids and other monuments’.

Herodotus records that, when Xerxes wanted to cross the Hellespont in 480 BC, he built a bridge of boats lashed to six cables, two of flax and four of papyrus. The Colosseum in Rome, circa AD 80, was covered for performances by awnings that took 300 men of the imperial fleet 4 days to erect. A modern analysis indicates that the hemp cables used to support the canvas had a diameter of 50 mm, a weight of 3 kg/m, a failure stress of 30–40 Mpa, and a modulus of 300–400 MPa (Croci et al., 1994).

The earliest record of the process of making ropes is on a tomb in Thebes from the Egyptian Fifth Dynasty, nearly 5000 years ago, which has the inscription ‘twisting the ropes for boat-building’ (Gilbert, 1954). More detail is shown in Fig. 1.4, a painting of ropemakers from the tomb of Rekhmire in Thebes, circa 1450 BC, using methods that still persist today. The technology established by ancient civilisations hardly changed until the middle of the twentieth century. Interestingly, the later volumes of the History of Technology published in the 1950s make no mention of ropes.

Fig. 1.4 Leather rope makers from a tomb in Thebes, circa 1450 BC. From Gilbert (1954).

Through the centuries, ropes have been used for many purposes: in shipping, in farming and fishing, in bridges, in climbi...

Table of contents

• Cover image
• Title page
• Disclaimer page
• Table of Contents
• Copyright page
• Preface
• Acknowledgements
• Author contact details
• 1: Introduction to fibre ropes
• 2: Ropemaking materials
• 3: Rope structures
• 4: Properties of rope
• 5: Rope mechanics
• 6: Rope production
• 7: Terminations
• 8: Use of rope
• 9: Inspection and retirement
• 10: Testing
• 11: Consumption, markets and liability
• 12: Case studies
• Appendix I: Quantities and units
• Appendix II: Braid and plait terminology
• Appendix III: UK trade data
• Appendix IV: The theory of backtwist
• Glossary
• References
• Index