Image Courtesy of : Stewart Cornelius (LV-HV Cable Jointer).
Pictured: Offshore Cable Cleating – 33kV Single Core Cable Containment. 185sqmm aluminium cables and 630sqmm copper cables out of the offshore hang-off using 316 stainless steel cable cleats.
Subscribe now to our POWER NEWSLETTER– a monthly email circulation packed with news, projects, videos, technical tips, training information, promotions, webinars, career opportunities and white papers.
Includes access to our popular JOINTERS BLOG with contributions from utility professionals, linesmen and cable jointers working on MV HV EHV cables and overhead lines typically at 11kV, 33kV, 66kV and up to 132kV.
15,000+ Subscribers. ➡ 
Pictured: 132kV Prysmian Terminations – completed with Chris Barker (EHV Jointer)
Images Courtesy of: David Gorski (EHV Jointer at Wootton and Wootton Ltd)
Thorne & Derrick International are distributors for Prysmian Cable Components which includes their range of Bicon cable joints, cable cleats, cable glands and jointer tooling for LV, MV and HV cables.
Further Reading
Subscribe now to our POWER NEWSLETTER– a monthly email circulation packed with news, projects, videos, technical tips, training information, promotions, webinars, career opportunities and white papers.
Includes access to our popular JOINTERS BLOG with contributions from utility professionals, linesmen and cable jointers working on MV HV EHV cables and overhead lines typically at 11kV, 33kV, 66kV and up to 132kV.
15,000+ Subscribers. ➡
Pictured : Installing 132kV Prysmian Cable Joints Using Prysmian (Pirelli) Multi Ram Crimping Tool – the EHV cable jointer is shown wrestling with a 132kV XLPE insulated single core 1000sqmm copper cable prior to jointing using Prysmian straight joints.
132kV mechanical shearbolt connectors are currently undergoing type testing which will eventually negate the need for traditional style cable crimping by the jointer.
Thorne & Derrick International, based in the UK, are distributors for Prysmian Cable Components which includes their range of cable joints, cable cleats, cable glands and jointer tooling for LV, MV and HV cables.
Installer : Chris Barker (EHV Cable Jointer).
For almost 100 years Prysmian cables and systems (formally known as Pirelli Cables) have been designing, manufacturing, installing and maintaining High Voltage (HV) and Extra High Voltage Cable (EHV) Systems throughout the world.
Chris Barker is also experienced and certified to carry out the installation of the following HV and EHV cable joints and terminations :
Silec 220kV Straight Joints. Installed by Chris Barker (CB Jointing Ltd)
Further Reading
Subscribe now to our POWER NEWSLETTER– a monthly email circulation packed with news, projects, videos, technical tips, training information, promotions, webinars, career opportunities and white papers.
Includes access to our popular JOINTERS BLOG with contributions from utility professionals, linesmen and cable jointers working on MV HV EHV cables and overhead lines typically at 11kV, 33kV, 66kV and up to 132kV.
15,000+ Subscribers. ➡
Image Courtesy : Necdi Cetin (Bachelor of Technology Akhisar Endüstri Meslek Lisesi)
Pictured: Brugg 132kV Joint – Saudi Arabia Riyadh Project
Further Reading
Subscribe now to our POWER NEWSLETTER– a monthly email circulation packed with news, projects, videos, technical tips, training information, promotions, webinars, career opportunities and white papers.
Includes access to our popular JOINTERS BLOG with contributions from utility professionals, linesmen and cable jointers working on MV HV EHV cables and overhead lines typically at 11kV, 33kV, 66kV and up to 132kV.
15,000+ Subscribers. ➡
A TRV Study for a UK Offshore Windfarm
Enspec Power have released a case study of a TRV assessment for a UK Wind Farm.
This assessment was done to ensure the 33kV Circuit Breaker was sufficiently rated for the sites 2.5MVAr shunt reactor.
Enepec Power carried out full modelling of the medium voltage network, site and shunt reactor to investigate the peak TRV and RRRV values and compared these against the breaker ratings.
The full case study can be found via download. The full redacted paper is available on request from Thorne & Derrick.
This report was produced by Enspec Power Ltd – it details a Temporary Recovery Voltage (TRV) study carried out for ABC Wind Farm in order to assess TRV ratings of the shunt reactor circuit breaker.
The following events have been investigated: De-energisations of the shunt reactor, credible single phase-to-ground and three phase-to-ground faults, simulations of the worst case TRV peak and Rate of Rise Recovery Voltage (RRRV) values of the vacuum circuit breaker (VCB), with a comparison of the results with the switching capability of the VCB according to IEC 62271-100, and finally a discussion of the possible solutions in order to reduce the TRV to below VCB ratings.
In conclusion, the investigations found that the TRV values for the de-energisation of the shunt reactor and the fault interruption of a three phase-to-ground and single phase-to ground fault at the reactor terminals were not compliant with the corresponding envelopes described in IEC 62271-100 (T10 / T60).
The probability of a fault between the VCB and shunt reactor terminal is low. Nevertheless, the de-energisation of the shunt reactor would be considered as frequent. Thus, a TRV / Overvoltage suppression / mitigation method should be considered. It is essential not only for the TRV requirement, but also for protecting the reactor against over voltages.
An RC snubber with appropriately sized SAs, or controlled switching with appropriately sized SAs are considered to be the best solutions to suppress the TRV to below the breaker ratings, minimise/eliminate probability of reignition phenomena and reduce the overvoltage stress at the reactor terminals. Note that independent pole operation is required for the solution of controlled switching.
Enspec Power help organisations to make money and to save money – professional engineers can do this! They’ve been making businesses more profitable since 1998 when their sibling founders, fed up with the bureaucracy of larger organisations, decided to go it alone and set up Enspec as a friendly, flexible engineering company.
Two decades on, they’re still a friendly bunch and one of the UK’s leading independent specialists in power quality engineering. They really understand electrical power systems and are passionate about what we do and what’s happening in the wider world of technology.
They are progressive members of The Institution of Engineering and Technology (IET) with links to academia – so if they don’t have the immediate answers, chances are they know somebody that does. They offer specialist engineered products and services such as Power System Studies, Power Factor Correction, Harmonic Filters, Reactive Compensation, Point-on-Wave Switching and Site Services. They’re here to help all manner of heavy electricity users such as utilities and renewables, oil and gas, manufacturing and other industries.
Company News
Specialist Suppliers of High Voltage Electrical Equipment & Cable Accessories
Thorne & Derrick International are specialist distributors of LV, MV & HV Cable Installation, Jointing, Duct Sealing, Substation & Electrical Equipment – servicing UK and global businesses involved in cable installations, cable jointing, substation, overhead line and electrical construction at LV, 11kV, 33kV and EHV.
THORNE & DERRICK Product Categories: Duct Seals | Cable Cleats | Cable Glands | Electrical Safety | Arc Flash Protection | Cable Jointing Tools | Cable Pulling | Earthing | Feeder Pillars | Cable Joints LV | Joints & Terminations MV HV
Distributors for 3M Cold Shrink & Scotchcast | Nexans Euromold | Pfisterer Connex
Published 18 Mar 2026
INDUSTRIAL LABEL PRINTING SOLUTIONS When clear, durable and professional identification is required across control panels, cable systems, production facilities and industrial installations, print quality, reliability and ease of use are critical. Cembre industrial label printers are designed to support...
Published 18 Mar 2026
HIGH VOLTAGE JUNCTION BOXES & ENCLOSURES When high-voltage power distribution and cable termination are required, safety, enclosure integrity and long-term reliability are critical. HV Junction Boxes and Electrical Enclosures manufactured by Abtech are engineered for the safe distribution, cable termination and protection...
