Synthetic solutions grow alongside project demands
By Hannah Sundermeyer01 October 2018
Rigging gear that utilizes synthetic materials will play a huge role in the future of rigging gear, according to Samson Market Strategy Manager Justin Smoak.
“As today’s construction payloads continue to push the limits of engineered lifting, traditional rigging has become heavier – and therefore more difficult to handle – and potentially more dangerous,” he said. “As lifting complexity increases, so does the possibility of costly delays, safety risks and increased operating expenses for construction contractors and lift planners.”
With 140 years of experience in the cordage industry, Samson is an aggressive leader in the development and manufacturing of high-performance ropes. The company has been developing and testing synthetic ropes and sling products since the 1950s and was among the first companies to develop a synthetic rope to replace wire rope in cranes.
Many companies around the world have begun researching, developing and testing synthetic materials and rope for the construction, rigging, lifting and transportation industry. While synthetic slings have become a mainstay in today’s rigging operations, synthetic rope use in cranes is still in its infancy. ACT reached out to synthetic rope and sling producers to help assess future implications for this realm of rigging gear.
Strength and durability
As a manufacturer and distributor of lifting and rigging products, Mazzella has seen the benefits that synthetic rope can provide in certain applications. When compared to wire rope and other steel lifting mediums, Plasma Synthetic Rope offers strength and durability, a lightweight and flexible design and increased safety.
The Plasma slings used by Mazzella are ergonomic for the rigger due to weight-savings versus a comparable steel wire rope sling or alloy chain sling.
Plasma rope often has equal or greater strength, size for size, when compared to wire rope, Mazella said. Because synthetic ropes are made of fibers and not metal, they’re resistant to corrosion, UV rays, rain, snow, ice and extreme temperatures. They’re also resistant to chemicals including bleaches and some acids, and they perform in fresh or salt water applications because they’re neutrally buoyant and resistant to liquid absorption.
HMPE synthetic rope is about 1/7th the weight of a comparable wire rope. Plasma Rope has a torque-free braided construction – making it ultra-flexible with a low D:d ratio (the ratio of the diameter around which the sling is bent, divided by the body diameter of the sling) for smooth spooling and fatigue-resistance when bending over sheaves. Plasma slings are ergonomic for the rigger due to weight-savings versus a comparable steel wire rope sling or alloy chain sling.
Plasma Synthetic Rope doesn’t store built-up energy like steel does. In the event of a break or failure, there is no whipping or recoil motion of the rope, or projectiles that could injure nearby workers. When steel rope or chain breaks, the reaction is violent and can injure workers or damage nearby equipment. When Plasma Rope breaks, the line simply falls to the ground.
Mobile crane usage
Synthetic hoist ropes for crane applications have already been successfully in use at WireCo World Group for many years, including ship cranes and in various lifting devices. Their use in mobile cranes, however, represents a special challenge as the rope must be able to provide an optimal balance between breaking load and weight. Both the limited axle load of road-approved vehicular cranes as well as the limitation on transport weight for crawler cranes has led to a steadily increasing breaking load combined with a constant rope diameter. Replacing these high-performance steel ropes with ones made of synthetic materials requires special fiber materials with a tensile strength similar to that of steel.
WireCo offers the rotation-free hoist rope Lanko Lift S for use with mobile cranes.
Ropes made of such special fibers are already available and WireCo already offers the rotation-free hoist rope Lanko Lift S.
The bright yellow rope consists of 12 braided outer strands made of the high-tech material Dyneema. The properties of these special fibers result in a breaking strength equal to a steel rope of the same thickness. The construction of the rope core is designed to achieve the required resistance to transverse pressures.
Laboratory tests have produced excellent results for breaking strength and projected service life based on the reversed bending cycles completed during testing. An additional noteworthy feature is the special coating treatment applied to the fibers to reduce interior friction and increase UV resistance. Tests in crane systems are on-going and show exceptional success. Not only do these characteristics make the handling of the product easier during installation and hook block changes, but they are also suitable for higher payloads, especially with higher lifting heights and longer jib lengths. The low maintenance requirements are a further advantage, since synthetic ropes of this type are corrosion-proof and require no further lubrication.
High performance fiber rope lifting slings from the heavy lift division of Lankhorst Ropes increase the lifting options for offshore contractors. They maximize crane lifting capabilities, provide a gentler lift and extend the reach of lifting and deployment systems in deep-water. The Lankoforce range of ropes produce slings with a minimum breaking load of around 2,000 tons in single leg configuration and 3,200 tons in a grommet configuration. Lankoforce HL slings are available in two configurations, eye-and-eye and endless loop (sometimes referred to as grommet).
Lankoforce HL slings can be provided with a variety of different protective jackets to prevent damage to the sling base rope. Where heavy abrasion is expected, a braided Dyneema jacket is used. The jacket also prevents damage to the rope’s load-bearing fibers due to abrasion, cutting, particle ingress or UV degradation. Lankhorst Ropes also has an on-going research and development program into the performance of high-performance fiber rope slings.
“We have chosen to look at the complete lifting system, recognizing that the slings are part of a complex system where interfaces between the sling, sling arrangement, crane, hook block, spreader bar, connecting hardware and lifted mass need to be understood and managed,” said Rui Pedro Faria, senior R&D engineer at Lankhorst Ropes.
Lankoforce HL slings have been developed as part of this program. The R&D program involves testing under realistic scenarios to develop comprehensive understanding of sling performance and behavior exposed to the combined effects of interfaces, boundary conditions and failure modes. As specific output, design information such as bending efficiency reductions, accurate stiffness data (dynamic/static), temperature behavior of rope slings during operations and other characteristics can be used as input for engineering lifting system design.
A worthwhile alternative
The argument for using synthetic ropes as an alternative to standard wire rope for crane and rigging operations is gathering pace across a range of industries.
Slings developed by the Cortland Company were recently used in Ohio to lift a 500-ton tunnel boring machine from a heavy haul trailer. Plasma 12 by 12 rope slings were used to safely elevate and transfer the machine underground. The strength and elastic properties of the Plasma 12 by 12 slings comes from a load-controlled process of precise braiding, which is subject to rigorous destructive testing prior to deployment.
The synthetic slings were spliced into custom lengths of 63 feet, with each section weighing 135 pounds. In comparison, the same length of steel rope would be at least seven times that weight – around 1,045 pounds. The slings also had a minimum breaking strength of 780,000 pounds, equal to that of steel.
The Ohio tunnel boring lift also showcased the ease of handing high-performance synthetic slings, which are about half the size of bulky round slings, according to Cortland. They also proved to be robust with a low stretch load limit of 1 percent, again equivalent to that of steel. This clearly demonstrates that alternative, synthetic rope can compete like for like with traditional steel in any onshore or offshore project, Cortland said.
“When used properly and in-line with specialist advice, a synthetic sling offers a viable alternative to wire rope, which has been the standard option across industries for many decades,” said Brooks Nunley, technical sales manager at Cortland. “As well as being easier to handle, intensive testing ensures they are tough enough to perform and withstand any challenging lift and transfer operation.”
Quick and easy
Hooks also play a crucial role in rigging, and are essential in any synthetic set-ups. Ideal for use with synthetic slings, Columbus McKinnion Quick Connect Hooks are the quickest and easiest way to add hooks to any synthetic sling by eliminating the need for additional hardware or assembly tools. Designed with a large bearing surface, these hooks prevent the sling from bunching, allowing the sling to be used at full capacity. The bearing surface is smooth and flat to prevent abrasive synthetic sling damage. The hook design also protects the sling, eliminating wear caused by sharp load edges and the need for additional edge protection, the company said. Made in the U.S., CM Quick Connect Hooks are available in four capacities up to 13,200 pounds, with web sling eye widths up to three inches.
Designed specifically for use with synthetic slings, CM Flat Eye Rigging Hooks provide a wide, smooth, load-bearing surface that won’t damage synthetic material, promoting longer sling life.
When working with synthetic slings, the CM Weblok assemblies allow for quick, easy and safe sling attachment. For use with round slings, web slings and high-performance synthetics, CM Webloks are available in two designs. Synthetic-to-attachment Webloks
combine the industry-leading CM Hammerlok coupling link with a CM synthetic sling attachment. Simply connect a sling to the synthetic sling attachment of the Weblok and a master link or other rigging attachment to the Hammerlok portion to efficiently and safely lift the load. Also designed specifically for use with synthetic slings, CM Flat Eye Rigging Hooks provide a wide, smooth, load-bearing surface that won’t damage synthetic material, promoting longer sling life. The flat eye opening eliminates bunching and pinching of the synthetic sling, providing significantly higher synthetic sling strength as compared to standard round eye-type fittings. Eye width exceeds WSTDA recommended radii to further ensure maximum ultimate synthetic strength is achieved.
A hybrid solution
Samson has developed Agile, a patented design to address the concerns for weight, safety, scheduling and handling of engineered lifts requiring sling strengths of 50 to 4,000 tons. Utilizing its proven rope technology AmSteel Blue synthetic lines, Agile is a hybrid product that combines the advantages of both round and rope slings into one lightweight, easy-to-handle and easy to inspect rigging system for heavy payloads.
Agile uses Samson’s advanced proprietary performance modeling software, empowering engineers to meet complex lift requirements quickly and with pinpoint accuracy, the company said. Using customer design requirements and specifications, Agile generates a sling model customized to fit the customer’s parameters. Moreover, the configurator generates additional lift options and design solutions for cost or schedule considerations.
Round sling technology
Twin-Path Synthetic roundslings for heavy lifting by Slingmax Rigging Solutions are the only synthetic roundslings available on the market that come equipped with the Check-Fast External Warning Indicator, Covermax Cover and Rifled Cover technology.
Slingmax has been a supplier of high performance synthetic roundslings to the industrial and heavy lifting markets since 1986. The Check-Fast Inspection System is designed to improve jobsite safety. The Check-Fast External Warning Indicator (EWI) provides a criteria for pass/fail inspection when the internal load-bearing core yarn may be damaged. The Check-Fast Inspection System can also indicate ultraviolet (UV) light degradation, fiber-on-fiber abrasion, fatigue and severe overload.