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.
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.
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).
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
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.
PFISTERER Cable Jointer Training Courses
Medium & High Voltage Jointer Courses from PFISTERER | 33kV & 66kV
PFISTERER are working in co-operation with their UK Distributor Thorne & Derrick to promote and deliver Medium Voltage CONNEX & SEANEX Training Courses from PFISTERER’s purpose built training facility in the UK.
When expertly installed by Competent & Certified Jointers the PFISTERER range of Cable Accessories operate reliably and are absolutely maintenance-free over decades.
Safety and reliability are essential factors in MV & HV Power System applications placing particular demands on cable preparation, accessory assembly and installation skills of the cable jointer.
The Training Courses are aimed at professional installers as well as technicians, engineers and other project managers with several years‘ experience and appropriate skills in the installation of medium or high voltage cables.
You can contact Thorne & Derrick to arrange your PFISTERER training course today, call 0191 4104292.
CONNEX & SEANEX Jointing Courses
PFISTERER also has a worldwide trainer network: so training courses can be held close to you anywhere in the world.
The training courses provide the MV- HV Jointer with the required product know-how demonstrated in many practical examples. All training courses include:
After successful completion of the training course, every participant will receive a time-limited certificate for the trained PFISTERER product.
Different training courses are available throughout the year – contact us to discuss your requirements.
➡ Please Note – Only specialists certified by the manufacturer are allowed to perform the installation of High Voltage Cable Accessories. This is required to secure your warranty claims.
(all prices are per person)
PFISTERER offer a wide range of other training courses that can be tailored to suit your needs please contact Thorne & Derrick for further information.
➡ SEANEX | Jointers currently certified as Competent by PFISTERER to install the CONNEX range of 33kV inner cone separable connectors must arrange for additional certification to install the SEANEX range of products at 66kV.
SEANEX – High Voltage Connector for Offshore Inter-Array Cabling. SEANEX is a dry pluggable inner cone connection and contact system especially for renewable energy and offshore high voltage power systems up to 72.5kV
Contact us to discuss your specific medium/high voltage jointing training requirements.
Thorne & Derrick stock and recommend the use of Alroc tools for the preparation of medium/high voltage cables to effectively remove the cable sheath, semi-con screen and insulation.
Extensive, in-depth experience in working with and installing medium and high voltage cables is a prerequisite for participation in the PFISTERER training courses. Training courses are held in English. Participants must be able to understand and speak the respective language or the customer must provide a qualified interpreter.
The PFISTERER certificate will only be awarded to the participant on successful completion of the training course.
Cancellation Costs: Up to 14 days before the training course. Cancellation costs for bookings/reservations (hotel, flight, etc.). Less than 14 days before the training course: 50% of the cost of the booked installation training course and cancellation costs for bookings and reservations.
Dates: All training courses are held throughout the year.
Dates on request contact Thorne & Derrick.
Prices: Valid until June 2022 (pricing terms and conditions are subject to change).
PFISTERER Training CONNEX MV & HV
Stocked & Supplied by Thorne & Derrick
THORNE & DERRICK are national distributors of LV, MV & HV Cable Installation, Jointing, Duct Sealing, Substation & Electrical Equipment – we service UK and global businesses involved in cable installations, cable jointing, substation, overhead line and electrical construction at LV, 11kV, 33kV and EHV.
Thorne & Derrick stock and distribute PFISTERER CONNEX Connectors for medium / high voltage cable connection and termination to electrical systems up to 33kV – we provide competitive prices for PFISTERER CONNEX connectors used to terminate and connect polymeric insulated MV-HV cables into gas insulated switchgear and electrical equipment from extensive UK stocks.
Country Manager UK & Ireland
“Since 2018 when Klauke were acquired by Emerson along with the Greenlee and Ridgid brands, Thorne & Derrick have helped our Group supply contractor requirements with tools for cable crimping, cutting and punching electrical 
panels.
Today our partnership is going from strength to strength.
Thorne & Derrick’s Sales Engineers receive ongoing training at their offices to promote technical competence and build commercial confidence in our tooling products – they are supported by Klauke’s national field sales team to provide onsite or online product demonstrations to end users when and wherever required.
Since 1985, Thorne & Derrick have gained a solid reputation for contributing to improvements in Workplace Electrical Safety throughout the industry – this includes assisting the launch of product innovations into the market, such as the Greenlee LS50 & Klauke VDE Orange and being a “go-to” supplier of electrical safety equipment to power industry contractors working with underground cables or overhead lines.
Increasing sales of our Strut Channel Cutter are an excellent example of a success story – the RIDGID STRUTSLAYR is recognised as the strongest and safest strut channel cutter on the market and is available from Thorne & Derrick stocks.
The sales and marketing staff at Thorne & Derrick worked hard and smart on introducing the STRUTSLAYR product to their clients and marketplace during COVID and are now seeing the impressive sales results.
Together during 2022 we welcome the opportunity to jointly promote more Workplace Electrical Safety improvements to be delivered through product innovations including the first remote-controlled cable cutters – for example, the Klauke ESG105RMCCFM and ESG65RMCCFM battery-powered, hydraulic cutting tools which will allow the user to maintain a safe distance whilst cutting cables,” comments Paul.
Featured Product
RIDGID together with Thorne & Derrick introduce an innovative Strut Channel Cutter that improves workplace electrical safety called STRUTSLAYR™ which offers reduced risk of sparking when compared to grinders and chop saws and still manages to produce a clean, consistent cut.
The RIDGID® STRUTSLAYR™ delivers shop quality, burr-free strut channel cuts on the jobsite in 5 seconds or less. Compatible with RIDGID 32kN press tools, the STRUTSLAYR strut cutter offers a clean, consistent cut with a simple pull of a trigger.
STRUTSLAYR | Stocked by Thorne & Derrick
Thorne & Derrick provide competitive prices and fast delivery for the range of Klauke cutting and crimping tools. Cable cutting and crimping tools manufactured by Klauke are renowned for high-quality, electrical connection tools for crimping, cutting and punching – special cable tooling solutions for applications in a range of different sectors.
LV MV HV Power, Cables, Jointing, Substation & Electrical Discussion Group
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 Joints, Terminations & Connectors to enable the installation of low, medium and high voltage power cables into underground trench or duct.
Key Product Categories: Connectors, Joints & Terminations MV HV | Cable Preparation & Jointing Tools | Duct Seals | Cable Transits | Cable Cleats | Cable Glands | Electrical Safety | Arc Flash Clothing & Protection | Cable Pulling | Earthing & Lightning Protection | Feeder Pillars
Main UK Stockists for: 3M Electrical, PFISTERER Connex, Nexans Power Cable Accessories (Euromold), Alroc, Ellis Patents, ABB, Roxtec, Cembre & CATU Electrical.
33kV Voltage & Capacitor Tester – Horstmann TP-1
33kV Voltage & Capacitor Tester for Euromold & NkT Connectors
Horstmann TP-I is a two-pole voltage detector according to VDE 0682 Section 415 for determination of the operating status of high voltage systems – the voltage detector is exclusively for use at capacitive LRP-test points of separable connectors:
The Horstmann TP-I must not be applied directly at high voltage.
For testing voltage the clamp of the helix cable has to be connected with earth potential . Second the contact electrode has to be connected to the capacitive test point of the plug type cable connection.
During testing grasp only the handle of TP-I. Reaching over from the handle onto the insulated part is not allowed. Three red blinking LEDs indicate “voltage present”. This indication appears in three-phase systems in the range of 45% and 120% of rated voltage, but not below of 10% of rated voltage.
TP-I has no battery supply. During precipitation it is not allowed to use the voltage detector. Ensure that voltage detector is kept clean and dry, otherwise voltage detectors are maintenance free. TP-I must be subjected to a maintenance test according national regulations, in Germany every 6 years at the last.
| Nominal Voltage | Printed on unit |
| Nominal Frequency | 50Hz |
| Flashing Frequency | ≥1Hz |
| Operate Voltage | ≥70Hz at test point |
| Climatic Conditions | N,W (-25°C…+70°C) |
| Display “Voltage Present” “No Voltage” |
Red blinking LEDs No indication |
| Housing Material | Noryl |
| Weight | ca. 0,7kg |
| Length | 920mm |
| Length of isolation rod Li | 540mm |
HORSTMANN TP-1
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 Joints, Terminations & Connectors to enable the installation of low, medium and high voltage power cables into underground trench or duct.
Key Product Categories: Connectors, Joints & Terminations MV HV | Cable Preparation & Jointing Tools | Duct Seals | Cable Transits | Cable Cleats | Cable Glands | Electrical Safety | Arc Flash Clothing & Protection | Cable Pulling | Earthing & Lightning Protection | Feeder Pillars
Main UK Stockists for: 3M Electrical, PFISTERER Connex, Nexans Power Cable Accessories (Euromold), Alroc, Ellis Patents, ABB, Roxtec, Cembre & CATU Electrical.
UKEx Certification
Following changes to the acceptance of ATEX/IECEx certification in the UK, Nexans are please to announce that the ATEX-IECEx certified Nexans accessories now also have the UKEx marking on the label.
This UKEx certificate, granted to Nexans products for the UK market, is added to the ATEX-IECEx installation instructions of the range of the certified EUROMOLD Separable Connectors Interface A to F.
Nexans Power Accessories contracts the CML Notified body which checks 3 levels of explosion protection on ATEX-IECEx certified products:
The applicable level for Nexans Power Accessories is #2 above.
As with IECEx certificates internationally and ATEX certificates in Europe, CML provides the UK Conformity Assessed (UKCA) marking, which is a certification indicating the conformity with the applicable requirements for products sold within the United Kingdom, which became part of UK law on exit day of the EU, January 31st, 2020.
Nexans is the only supplier world-wide to offer UKEx/ATEX/IECEx certified separable connectors, which are tested to provide a very high degree of safety in use, especially for potentially explosive atmospheres.
Our “ATEX” accessories are frequently found installed safely in industries with high technical requirements like the chemical industry, Oil & Gas, offshore platforms, and are installed in equipment such as pumps and three-phase motors.
ATEX – IECEx
Components intended for use on/in equipment or protective system intended for use in potentially explosive atmospheres:
ATEX – Certificate
Conform with ATEX directive 2014/34/EU
IECEx Certificate
Conform with IEC standard
IEC 60079-0:2017
IEC 60079-7:2015
Thorne & Derrick have an International Distribution Agreement with Nexans Power Accessories UK and are their main stockists and suppliers for their range of Heat Shrink Joints & Terminations up to 33kV.
Specialist Distributors of Industrial & Hazardous Area Equipment to provide Power, Heat, Light & Ventilation to the explosive atmospheres and process industries.
Control Panels | Plugs | Isolators | Enclosures & Junction Boxes | Lighting | Control Stations | Motor Starters | Heat Trace | Gas Detection | Flame Detection | Process Instrumentation | Process Heating | Ventilation Fans | Security Access Control
Competitive Prices | Extensive Stocks | Technical Support | Express Delivery
Published 02 Sep 2026
Celebrating Charlie & Ella’s Level 4 Sales Executive Apprenticeships At Thorne & Derrick International, we are proud to champion talent development and recognise the dedication required to achieve professional growth. We are therefore delighted to congratulate Charlie Baines and...
Published 11 Aug 2026
Thorne & Derrick will be Exhibiting at Solar & Storage Live UK 2026 at the NEC Birmingham from 22nd–24th September, showcasing our support for HV Cable Accessories, Joints, Terminations, Separable Connectors, Cable Tooling and Grid Connection Products used across...
