A winning delivery model should be based on collaboration with existing partners and navigating accepted standards

In preparation for the increase in rolling stock and additional berthing requirements, Cleshar was awarded the contract to extend two of the existing sidings at Strawberry Hill depot and in addition successively secured the contract to carry out the DC power upgrade.

Cleshar’s delivery model provided the ability to self-deliver the civils, permanent way, traction power, negative & positive cabling and track welding whilst making use of supply chain partners to deliver the mechanical and electrical package.

The scope of works for the alteration to the sidings included:

  • recovery and removal of the two existing siding loops
  • removal of an existing vegetation bund followed by the installation of earth retaining structures
  • installation of the track formation project for the extended sidings, retaining walls and permanent way installation
  • reconfiguration of traction power
  • enhancements to depot lighting and associated walkways.

Included within this package of works was the installation of 1 kilometre of troughing, Track Disconnector bases and busbar bases.

The initial phase of the works was delivered over a four-month programme within an operational depot environment. During construction, the depot remained fully operational with no disruption, safety issues or delays to completion. With the depot being principally a driver’s depot the primary focus was to ensure that the normal depot activities were unhindered during construction ensuring that all client staff needs were facilitated and disruption minimised.

This required close collaboration between the delivery team and client with good relations maintained throughout the works. Once the worksite was identified and agreed with the depot management team, the existing walkways were diverted and the segregated zones setup the existing vegetation bund was excavated to the required level. Excavated spoil was continually transferred to a material laydown area which was then disposed of at a time least disruptive to the depot. The underlying formation was then built up using type 1, compacted at 150mm layers and excavation for additional lighting columns and bases cast.

Bottom ballast, sleepers and the track to both roads were installed the plain lining of a set of points followed by the installation of two new buffer stops, new walkways and the single and double cantilevered LED lighting along with the associated transformers, distribution boards and components.

DC power upgrade

In preparation for the power upgrade, Cleshar was commissioned to resection the existing power feeding arrangements within the depot and install approximately 1 kilometre of C 1/9 troughing running through the depot.

This was required to house the new R6 circuit, the alterations to the existing R4 & R5 circuits and provide cable route management for the new negative bonding arrangements. Two new busbar bases and four track disconnector bases were also installed along with associated routes for interconnections. Following the completion of this first phase of the works, Cleshar was awarded the contract for the DC power upgrade, which is currently in progress.

The works required for the DC upgrade are being delivered utilising Cleshar’s internal resources and as two distinct elements of work. The ETE works: which encompass the positive cabling, negative bonding, continuity bonds and replacement of guard boarding. The second element of the works involve the installation and commissioning of a DC circuit breaker, point to point controllers and modifications to the mimic panel at Raynes Park ECR.

The positive cabling required 2 new 1,000mmsq cables to be installed from the reinstated DCCB for electrical section R6 and alterations to the existing electrical section R4 & R5. Existing hookswitches were upgraded to the Mark VIII variety and cables doubled.

Four new track disconnectors, previously known as track isolation switches have been installed to provide a safer means of isolating the respective electrical sections when required.

The negative bonding arrangements entail the installation of two negative busbar units. Six new 800mmsq negative return traction cables were installed from the first busbar within the depot to the second busbar situated in close proximity to the Fulwell substation. Inter track cross bonds were replaced throughout the depot as well as continuity bonding around any fishplated running rail joints.

Existing double guard boarding has been replaced with new boarding where required throughout the depot. The second element of the DC power upgrade is required to provide alternative feeding arrangements and additional power capacity to support the longer and new rolling stock being stabled at Strawberry Hill Depot.

The works required a redundant Bertram Thomas HSE DC circuit breaker (DCCB) which previously supplied Strawberry Hill depot to be brought into service. The existing remains of the redundant DCCB are to be removed from Fulwell substation and a refurbished and functioning DCCB is to be installed. A spare DCCB was made available along with additional spare units to facilitate the refurbishment of the DCCB, which will then be tested, installed and commissioned. The copper work required for the installation of the DCCB is to be surveyed and fabricated.

In conjunction with this, new point to point controllers are to be installed at Fulwell and Hampton substations along with alterations to the mimic control panel to provide the additional control key and the reinstatement of supervisory equipment for control and indication.

The scheme will then be commissioned in conjunction with South West Trains and Network Rail including end to end testing under load. The overall project has and will provide South West Trains with an asset which is vastly improved to cater for future demands and requirements.

About Cleshar

Cleshar is a long-established railway contractor providing infrastructure services specialising in the delivery of track, civils, construction and maintenance capability.

As part of the privately-owned CCS Group of companies Cleshar has been trading since 1992 working with Network Rail, London Underground, Docklands Light Rail, London Overground and London Trams. As a subcontractor, Cleshar has partnered with other contractors and manufacturers including Amey, Babcock, Balfour Beatty, Colas, Dragados and KONE. These relationships have underpinned the company’s growth over the years, with the business on target to turnover over £100 million.

With over 1,400 staff, engineers and technicians the business has a broad range of experiences and skills to deliver a wide range of services across the network. As well as permanent way expertise, Cleshar provides inhouse premises maintenance, vegetation control, protection services, safety and technical training and overall project management capability.

 

Tel: + 44 (0)20 8733 8888
Email: info@cleshar.co.uk
Visit: www.cleshar.co.uk