Cable Monorail System Hauling Series for Balfour Beatty

January 15, 2020

Client: Balfour Beatty
Project: Eleclink – Cable Monorail System Hauling Series
Completed: February 2019

Balfour Beatty Power Transmission & Distribution and Prysmian Power Link formed a joint venture to supply and install a HVDC 1000MW Interconnector between the UK and France. The “ElecLink” project required a cost effective, efficient and safe method of towing the cable monorail system (CMS) into the tunnel to the required permanent position; it depended on a series of On-Track Machines (OTM), which are wagon mounted mechanical winching units, known as Hauling units (HU), for the sole purposes of transitioning the cable.

The key features of the HU are:

  • Two skids fitted to a single KFA wagon to form a single HU
  • Control cabin including welfare facilities such as hot water, toilet and air conditioning
  • 15T Utility winch with Dynema bond
  • Tower gantry complete with pulley sheaves and bearings
  • Bespoke fabricated hydraulically operated and retractable stabiliser legs to provide additional lateral stability in winching operation
  • Automatic fire suppression system
  • CCTV system to allow for additional monitoring of areas where visibility may be restricted
  • LED lighting; installation of work lights, cab lights, deck lights
  • Radio remote control system for manual mode operation of winch and stabilisers
  • On board communication system

Project Deliverables
GOS was commissioned by Balfour Beatty to:

  • Design and manufacture in line with the principles with the Common Safety Method for Risk Evaluation and Assessment (CSM RA)
  • 5 HU’s in total to be designed and manufactured
  • Control system to deliver performance level d (PLd) monitoring of the cable tension
  • Allow transition of the HU to the next location within the tunnel whilst maintaining constant minimal tension preventing cable sag
  • Allow continuous motion of the interconnector cable when used with multiple HU’s
  • Provide inter-unit communication system that wirelessly (via fibre optic) sent HU data to all other HU’s and to a ground unit at the tunnel entrance

Challenges and Solutions
The timescales for the project were always the biggest challenge; Balfour Beatty required a first of type HU to be designed, built and delivered within 12 months ready to commence hauling straight away. Other manufacturers quoted a minimum timescale of 24-36 months for delivery of a project of this scale, however GOS managed to achieve this and complete the project with a total of 5 HU’s delivered in just over 18 months from project commencement.

Why GOS?
GOS Tool and Engineering Services Ltd has an established and award-winning team that combines design, engineering and delivery expertise across all rail activities and can be trusted with the most complex and demanding of projects.

GOS Tool and Engineering Services Ltd are an experienced OTP provider who work collaboratively with their clients and own supply chain as a reliable partner, providing exceptional expertise and proven project delivery in respect of yellow plant in the rail industry.

GOS proven track record for their ability to innovate and deliver which has seen them win tenders for developing new and exciting equipment at the forefront of the rail industry.