Cable Pulling & Laying

Conductor Repairs | CatchBlock OHL Catenary Roller From Slingco

April 20th, 2022

CatchBlock

Conductor Repairs

CatchBlock OHL Catenary Roller From Slingco

Slingco has developed a range of products to vastly improve conductor replacement. The Catchblock, the Conductor Replacement Roller (CRR) and our range of specialist cable socks and grips.

The challenges faced by the OHL (Overhead Line) industry due to the growing number of electrical infrastructure projects built beneath existing transmission and distribution networks – alongside increasingly stringent OHL regulations – can make maintenance costly, time-consuming and challenging.

Replace OHL conductor in half the time with no need for possession orders

CatchBlock

Lightweight, robust and easy to deploy, CatchBlock helps to increase efficiency and reduce costs.

CatchBlock is an innovative overhead line (OHL) catenary roller system.

A two-rope system, allowing the replacement of old-for-new conductors. In the event of conductor failure during this process, Catchblock enables the recovery of both ends without having to lower the system.

Removes the need to erect and dismantle scaffolding, significantly reduces the risk of accidents and harm to site workers and reduces cost and project timeframe.

Designed to deploy a twin-rope system, it allows the recovery and redeployment of broken conductors without the need to take possession of road/rail or client/third party property or infrastructure.

CatchBlock Features & Benefits

Removes the need to close down essential infrastructure for conductor repairs or in the event of an emergency
Cuts down the need for scaffolding, reducing accident risk
Lightweight, robust, weatherproof and easy to deploy
Twin rope system allows for recovery and redeployment
Flexible – CatchBlock isn’t specific to a single tug design
High conductor range, including the ability to allow mid-span joints/repair sleeves to pass through safely
Blocks can be connected for use on multiple bundle conductor systems

Conductor Replacement Roller (CRR)

Provides a simple, conductor-deployed protection system using a lightweight aramid rope.

The CRR unit enables the safe exchange of conductors in three easy steps:

Laying out the pulling cable, e.g. with an electric pulling robot.
Tensioning the CRR Block assembly.
Feeding a new conductor through the cable pulleys of the CRR Block.

The rollers have a spring loaded gripping feature to secure the rope laterally without impinging any rotational movement as the rollers rotate around the axis of the conductor.

Conductor Replacement Roller (CRR)

CABLE SOCKS & PULLING PRODUCTS LV MV HV

Complete range of LV, MV and HV cable pulling products for installation and enabling cable jointing in trench or ducts including LV, 11kV/33kV medium voltage (MV), 66kV/132kV high voltage (HV) and EHV transmission and distribution cables up to 400kV.

Thorne & Derrick distribute the most extensive range of Cable Installation & Electrical Distribution Equipment to the Power Transmission & Distribution industry in the onshore and offshore wind, solar, rail, oil/gas, data centre, battery storage and utility sectors.

We service UK and international clients working on underground cables, overhead lines, substations and electrical construction at 11kV and up to and EHV transmission and distribution voltages.

➡ See Also Further Reading

Earlier this year, Thorne & Derrick welcomed Phil Day from Slingco Limited, the world-leading manufacturer of cable pulling and support socks, swivels, cable protectors, wire rope assemblies and accessories. Phil provided an Offshore Wind focussed company presentation to our Sales Team (pictured left-to-right Sarah Henderson, Carl Cox, Jonathan Hewitt, Phil Day, Jeff Jhanke, Natalie Lundie and Chris Dodds.

Cable Socks – Proper Usage, Maintenance & Inspection for Pulling-in Cable

April 19th, 2022

Thorne & Derrick | Jointing, Termination & Pulling Equipment

Cable Socks

Have You Inspected Your Cable Socks?

Inspecting cable socks (also known as a cable grip and cable stocking) is not an exact science, but is crucially important to ensure safe cable pulling operations, maximum grip strength and grip longevity. There are a number of variables that can weaken cable socks that are not immediately obvious on visual inspection. However, there are some important and simple checks that you can do routinely to mitigate product wear, deterioration and potential accidents from happening.

When inspecting a cable grip, it is critical to know the potential damage and trouble spots. Below highlights the type of damage you need to be aware of prior to beginning any pulling project with your cable socks.

CABLE Sock INSPECTION

Safety is Slingco & Thorne & Derrick’s primary concern.

The products manufactured by Slingco are safety critical and must be used by competent trained personnel – it is essential to choose the right cable grip for the job. Inspecting a cable grip is not an exact science. There are a number of variables that can weaken a cable grip that are not immediately obvious on visual inspection.

This is why we work to Factors of Safety.

It is important to know the difference between Working Load and Approximate Break Load, and how to use the Factor of Safety to calculate the Working Load Limit for the cable grip that will be utilized. To maximize grip performance, we highly recommend utilizing banding on the ends of cable grips, as shown in the figure below.

WLL = ABL ÷ FoS

Cable Grip Factor of Safety (FoS) *

Overhead Pulling – 5 : 1
Underground Pulling – 3 : 1
Cable Supporting – 10 : 1

WORKING LOAD LIMIT

The Working Load Limit (WLL), sometimes also known as the safety working load, is the mass that the equipment being used can safely hold, pull, or lower without breaking. In short, it’s the maximum load that can be applied to the product safely when in general service.

The Approximate Break Load (ABL) is the load at which a new grip can be reasonably expected to break. This is measured on a straight line pull only, as side pulling, or angular loads, will produce different results.

The Working Load is calculated by dividing the Approximate Break Load (ABL) by the Factor of Safety (FoS). No component in the system should exceed the working load for the cable grip.

The Factor of Safety (FoS) is the “extra” coverage of the breaking load over the over the working load expected. Factor of Safety is often noted as “X to 1” or “X:1”. The Factor of Safety accommodates normal spikes in load tension that may occur when under load.

Note: Slingco recommends double banding the ends of cable socks.

When you are inspecting a cable sock, it is critical to be able to identify damage or potential trouble spots. The following are some of the types of damage you should be aware of prior to beginning a pulling project with your cable grips. If these are observed, replacement of grip should be considered.

Pulling & Supporting Power & Subsea Cables in the Wind Sector | Cable Grips

Pulling & Supporting Power & Subsea Cables in the Wind Sector | These cable socks manufactured from offshore/marine grade type 316 Stainless Steel are suitable for use in the renewable energy sector in applications such as cable installation (onshore and offshore), cable support inside wind turbines and cable management – used to pull, protect and support wind turbine cables. Pictured: June 2020 : the first of two export cables, each 37 kilometres in length, has been installed at the nearshore of Thorntonloch Beach as part of construction of the Neart na Gaoithe (NnG) Offshore Wind Farm.

CABLE SOCKS & PULLING PRODUCTS LV MV HV

We service UK and international clients working on underground cables, overhead lines, substations and electrical construction at 11kV and up to and EHV transmission and distribution voltages.

➡ See Also Further Reading

Earlier this year, Thorne & Derrick welcomed Phil Day from Slingco Limited, the world-leading manufacturer of cable pulling and support socks, swivels, cable protectors, wire rope assemblies and accessories. Phil provided an Offshore Wind focussed company presentation to our Sales Team (pictured left-to-right Sarah Henderson, Carl Cox, Jonathan Hewitt, Phil Day, Jeff Jhanke, Natalie Lundie and Chris Dodds.

Working Loads & Break Strength | The Key is Your Factor of Safety

March 21st, 2022

Line Pulling Swivels By Slingco

Working Loads & Break Strength

Safety is critical when dealing with utility, construction or maintenance projects.

One of the main ways to ensure safety is by working within the load limits of crucial equipment. Slingco promote the safety critical role of cable support grips and the need for independent break load testing to safeguard project, people and reputations.

Swivels designed for use in stringing high tension wires for electrical transmission and distribution. Line Pulling Swivels are important in pulling when the lines develop torsion during the installation. This torsion must be released.

Use of a swivel will release torque and prevent it from reaching dangerous levels, which can cause damage to the cable or cable socks.

Slingco also offers a ‘bull nose’ style swivel designed for underground and overhead applications. All swivels are stringently quality tested and inspected to ensure optimum performance and reliability with working Loads from 10 to 134 kN.

Working Loads and Break Strength

What is Factor of Safety?

This is the factor used to ensure sufficient break load to handle working load spikes. It is critically important that all devices and tools used for pulling conductor are rated for the working loads expected on each job.

Factor of Safety (FOS) is often notated as X to 1 or X:1. It is the ‘extra’ coverage of the breaking load over the working load expected. When pulling conductor or cable, many factors impact how much load your equipment must handle.

Sometimes the conductor can get hung up on something which will cause the load tension to spike. The factor of safety helps accommodate a normal spike without dropping wire or experiencing equipment failure.

How do you determine Break Load?

Break Load must equal or exceed the Working Load x Factor Of Safety.

To help explain this, imagine the tension for a pull is calculated to be 1,800kg – this is Working Load of the pull. If the equipment used is only rated to a Break Load of 1,800kg, any variation in the load tension over the standard can cause failure. So, project designers assign a factor of safety (FOS).

A FOS of 3 to 1 is commonly accepted in the UK for overhead line pulls. Different countries may have a different standard.

This means that the Break Load of any tool used must be 3 times the expected load tension. In this example:

Working Load of 1,800kg x FOS of 3 = Break Load of 5,400kg.
Grips and swivels would need to be selected with a break load of 5,400kg or more.

When selecting equipment for a pull, be sure you know whether items are rated at BREAK LOAD or WORKING LOAD. If rated at working load, you must know the Factor of Safety this working load is based upon to ensure it matches your project’s working load. If rated at break load be sure it meets your project’s break load including the Factor of Safety.

Here are a few common rules of thumb for the Utility industry:

Pulling & Support Grips – usually rated at approximate BREAK load. This means a factor of safety for your project must be applied. To determine the working load, divide the break strength by your project’s Factor of Safety. For example, a grip with an approximate break load of 5,400kg to be used on a project with a FOS of 3:1 has a safe working load of 1,800kgs.

Swivels – This is where it gets tricky (or trickier). Most (but not all) manufacturers will label swivels at a 3:1 FOS working load. Slingco (along with two other prominent manufacturers of swivels) go ahead and CONVERT THE BREAK LOAD INTO THE WORKING LOAD. Our 2,240kg swivel is rated for a 6,720kg Break Load – we have already built in the Factor of Safety of 3:1.

Connectors – (90 degree, Rope to Rope, Rope to Swivel): Similar to swivels these are typically listed at their rated 3:1 WORKING LOAD. Connectors are used to connect grips when pulling though a tensioner or around an angle greater than 50 degrees. Swivels should not be pulled around a tensioner. Swivels are not designed to handle the side loads experienced when going around a tensioner wheel. This can cause damage to the bearing structure within a swivel.

These are only a few of the tools used. Remember to make sure you understand how each tool is rated (Working Load at what FOS or Break Strength). The key to ensuring a safe project is making sure all tools meet or exceed your project’s Working Load.

➡ Contact Thorne & Derrick for technical support on your cable pulling, laying and installation projects.

Cable socks and support grips are available to enable the installation of 33kV 66kV array cables prior to MV HV Jointing & Terminating in windfarm towers, turbines and offshore substations.

Further Reading

Supplying Cable Termination, Jointing, Pull-in & Electrical Equipment up to 66kV

Specialist Distributors to the UK and international Offshore Wind & Renewable industry to provide safe and reliable LV HV Electrical Cable & Power Distribution Systems up to 66kV – we are highly customer responsive and absolutely committed to providing a world-class service. Contact our UK Power Team for competitive quotations, fast delivery from stock and technical support or training on all LV-HV products.

NOF Offshore Wind Industry

NOF Members Thorne & Derrick and Slingco Ltd Supporting Cables in the Offshore Wind Industry

January 14th, 2022

NOF Members Thorne & Derrick and Slingco Ltd Supporting Cables in the Offshore Wind Industry

Today, Thorne & Derrick welcomed Phil Day from Slingco Limited, the world-leading manufacturer of cable pulling and support socks, swivels, cable protectors, wire rope assemblies and accessories. Phil provided an Offshore Wind focussed company presentation to our Sales Team (pictured left-to-right Sarah Henderson, Carl Cox, Jonathan Hewitt, Phil Day, Jeff Jhanke, Natalie Lundie and Chris Dodds).

We look forward to further strengthening our position in the offshore wind sector with the support of Slingco and their team.

Thank you for visiting and updating us on the safety critical role of cable support grips and the need for independent break load testing to safeguard project, people and reputations.

Further Reading

Supplying Cable Termination, Jointing, Pull-in & Electrical Equipment up to 66kV

NOF Offshore Wind Industry

Greenlee Cable Pulling Equipment | Cable Laying Products for LV MV HV Underground Cables

December 14th, 2021

Cable Pulling Equipment | Greenlee

Greenlee

In 1996, Klauke the leading manufacturer of cable cutting and crimping tools expanded its electrical product portfolio with the acquisition of the Greenlee brand – with the focus on punching tools and cable management, Greenlee supports the safe and reliable installation of electrical cables and equipment to provide power distribution at LV MV HV networks.

Speedy Spinner | Cable Pulling Device

Easy Rollers | Cable Drum Rollers

Polyester Butler & Smart Bulter | Fibreglass Cable Pulling System

Fish Tapes | Conduit Rod Tapes

Cable Installation Lubricant | Electrical Cable Lubrication

➡ Catalogue Download

Contact Thorne & Derrick for competitive prices, stock availability and technical customer support on the complete range of Greenlee products for Pulling & Laying cables.

Thorne & Derrick distribute the most extensive range of Low & High Voltage Cable Installation & Electrical Distribution Equipment to the Power Transmission & Distribution industry in the onshore and offshore wind, solar, rail, oil/gas, data centre, battery storage and utility sectors – this includes the most extensive range of Cable Pulling & Cable Laying Equipment to enable the installation of low, medium and high voltage power cables into underground trench or duct.

We service UK and international clients working on underground cables, overhead lines, substations and electrical construction at LV, 11kV/33kV and up to EHV transmission and distribution voltages.

Key Products: MV-HV Cable Joints & Terminations, Cable Cleats, Duct Seals, Cable Transits, Underground Cable Protection, Copper Earth Tapes, Cable Jointing Tools, Feeder Pillars, Cable Ducting, Earthing & Lightning Protection, Electrical Safety, Cable Glands, Arc Flash Protection & Fusegear.

Distributors for: 3M Electrical, ABB, Alroc, Band-It, Cembre, Centriforce, CMP, Elastimold, Ellis Patents, Emtelle, Furse, Greenlee, Lucy Zodion, Nexans Euromold, Pfisterer, Polypipe, ProGARM, Prysmian, and Roxtec.

THORNE & DERRICK LV MV HV Jointing, Earthing, Substation & Electrical Eqpt

Specialist Distributors | LV MV HV Jointing, Earthing, Substation & Electrical Eqpt

Cable Pulling & Laying

Conductor Repairs | CatchBlock OHL Catenary Roller From Slingco

Conductor Repairs

CatchBlock

CatchBlock Features & Benefits

Conductor Replacement Roller (CRR)

CABLE SOCKS & PULLING PRODUCTS LV MV HV

Cable Socks – Proper Usage, Maintenance & Inspection for Pulling-in Cable

Cable Socks

CABLE Sock INSPECTION

WLL = ABL ÷ FoS

WORKING LOAD LIMIT

CABLE SOCKS & PULLING PRODUCTS LV MV HV

Working Loads & Break Strength | The Key is Your Factor of Safety

Line Pulling Swivels By Slingco

What is Factor of Safety?

How do you determine Break Load?

Supplying Cable Termination, Jointing, Pull-in & Electrical Equipment up to 66kV

NOF Members Thorne & Derrick and Slingco Ltd Supporting Cables in the Offshore Wind Industry

Supplying Cable Termination, Jointing, Pull-in & Electrical Equipment up to 66kV

Greenlee Cable Pulling Equipment | Cable Laying Products for LV MV HV Underground Cables

Greenlee

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