Case Studies

Penzance Long Rock Depot


Spencer Group




With the Great Western Railway’s (GWR) project to enhance its services and provide the first HS2 Deliverable, Penzance Long Rock Depot recently underwent a hugely complex redevelopment worth £20million. The project saw Orton Group awarded the £5million contract in collaboration with one of its biggest clients Spencer Group, to provide its services as part of the construction of the new state-of-the-art Train Care Depot and the comprehensive refurbishment of an existing shed which was incorporated in Spencer Group’s innovative envelope and cantilever steelwork design.

The project is the biggest that Orton Group has completed in its 26-year history and the most complex, with the acceleration of the project meaning it had to deliver its services 17 weeks early to meet the project’s timescales and those of GWR, Westminster and Transport for London. As a result, Orton Group had to identify innovations within the project and work closely with main contractors to design and deliver on time-saving and quality-assuring methods to speed up the process.


Scope of Works

Bringing in all of Orton Group’s divisions – Electrical, Mechanical and Maintenance – the project required over 70 of Orton’s staff to deliver the project. The project required a large amount of Orton’s operatives to work extensively away from home for the length of the project, with the team involved with the removals of existing redundant electrical and mechanical installations, as well as the design team working on innovative products to meet the project, specification and limitations on installation times and environmental conditions. All of this, whilst ensuring adherence to extremely stringent health and safety, environmental, rail and government legislation regulations.

Some of the services Orton Group provided over the 18 months included design, development, installation and testing.


The project consisted of four core elements:

  1. 11,000volt High Voltage diversions and installation of new 11,000volt transformers including new switchboards to provide the infrastructure to cater for increased electrical demand.
  2. Electrical and mechanical installations to a new build accommodation block consisting of an office block, welfare facilities and meeting rooms
  3. Electrical and mechanical installations to a new two-road train service depot building.
  4. Construction and development of an existing train depot building, which involved a new shed being built over the top of the existing shed, whilst maintaining the operation of the live rail depot including the electrical and mechanical services within. Then, the dismantling of the existing shed inside the new building, as well as the installation of new electrical and mechanical services – also maintaining the existing electrical and mechanical services throughout the duration of the rebuild project.

The electrical and mechanical works were 18-month, challenging and hugely technical, consisting of services including:

  • 11,000 high voltage diversions
  • Installation of new 11,000volt transformers
  • Generator and Auto-Failure Systems
  • Co-Ordination of New Distribution Network Operators (DNO) Supplies And Metering Systems
  • Mains Earthing Terminals and Earth Bonding
  • MCCB Panel Boards and Switchboards – Installations, Commissions and Upgrades
  • Lightning Protection Systems
  • Metering and Service Monitoring Units Installations
  • Transient Surge Suppression Systems Installations
  • Submain and Final Circuit Cabling
  • Rewiring of Existing Electrical Installations Whilst Maintaining the Operation of the Depot
  • Small Power Installations
  • 500volt Sure Supplies (Train Supplies When in The Depot)
  • Inspection and Testing of The Completed Installations
  • Audio and Visual Systems
  • Innovative Linear LED Lighting Solutions
  • Static Invertors and Central Battery Emergency Lighting Installations
  • CCTV Installations Door Access Systems
  • Structured Data Cabling and Cabinets


During the design development, considerations had to be given to a range of environmental, BREEAM, depot and Network Rail specific requirements for the project’s lighting installation. Strict adherence also had to be achieved for Fire Ratings, IP Ratings, Corrosion Resistance, Escape Routes, Oil / Fuel / Lubrication Resistance, 5G NR Compliance, and much more. All light fittings had to be specifically-manufactured to meet various legislative requirements and corrosion resistance due to the nature of the environment, as well as rounded lighting profiles to pit lighting due to space restrictions, and DALI Digital Addressable Lighting Controls Interfaced with the depot protection systems.

It also saw the coordination with a number of other depot services, which also posed restrictive challenges to installations such as:

  • Energy Monitoring through the Building Management System (BMS)
  • Integrated Fire Alarm System
  • Depot Personnel Protection System (DPPS)
  • A requirement for a Central Battery System
  • Daylight Harvesting
  • Presence Detection
  • Presence of Trains Both Internally and Externally

The project’s success was achieved through:

  • Development of a Linear VEKO Lighting System | This integrated lighting, presence detection, daylight harvesting and Fire Rated cabling within 6m aluminium, and corrosion resistant extrusions. This system not only met the criteria of the project but also reduced the high-level lighting installation from 12 weeks to just 2 weeks.
  • Central Battery System | This was linked to the BMS, Fire Detection and DPPS systems via a Digital Addressable Lighting Interface (DALI)
  • Pit Lighting | Developed with Holophane to enhance their Prismashield fitting to ensure compatibility with the use of oils, lubricants, fuels and jet washes within the pit areas of the depot sheds. The fitting was also chosen due to its low, curved profile which met the requirements of NWR standards for the reduced space within the pits
  • Holophane Denver Elite Range | Use of this for external lighting meant the high specification aluminium bodied fittings were developed to include a marine coating for additional protection in the harsh environment. The fittings were also chosen for their controlled asymmetric output which allows the limitation of light spillage to neighbouring residential estates. The range included bollard, wall mount, and column mount fittings which allowed the flexibility of coverage for all external areas of the 2km-long depot.
  • Office & Accommodation Lights | These were carefully selected due to the 24hr operation of the depot, and the consideration of local residents. With presence detection and daylight harvesting at the very core of the installation, the lighting was developed with consideration to the operational usage of each area of the building
  • Depot Personnel Protection Systems (DPPS)
  • Daylight and Motion Detection Lighting Control Systems
  • DALI System-Controlled Shed Perimeter Lighting
  • Energy Consumption Monitoring Systems | Tying into Building Management Systems
  • Overspill and Glare from the External Lighting | To Ensure No Impact on the Surrounding Local Residents and Adjacent Sources

All lighting works had to operate in conjunction with other linked systems, including:

  • Integrated Fire Alarm Systems
  • Depot Protection Systems
  • Emergency Central Battery Systems
  • Daylight Dimming
  • Presence Detection



To work alongside existing facilities at the depot and to link to new services installed by the Orton Group team including electrical and lighting works, it was also heavily involved in mechanical works which saw it specified to undertake the complete refurbishment (and upgrading of):

  • HV / LV Works
  • Gas Systems and Supplies
  • Boosted Main Cold Water Supplies and Wash Down Points
  • Data Collection and Storage
  • Air Conditioning
  • Energy Efficiency Surveys on Completed Works
  • Environmental Surveys on Completed Works
  • Ambi-Rad installations


  • Depot Protection Systems
  • Emergency Lighting Central Battery Systems
  • Fire Alarm Systems
  • Door Access
  • Security and Personnel-Only Systems
  • External Lighting

Project Challenges

No Closure

Despite the sheer size and scope of the project, Penzance Long Rock Depot remained fully operational throughout the duration of the 18-month project term, with contractors and staff on site having to work around the depot to ensure no pre-approved disruption to not only the public, but to staff, local residents and businesses.

Marine Environment

Careful consideration had to be given to the overall project’s impact on the coastal location. As part of the Considerate Contractors scheme and various other legislative requirements, Orton Group designed and created innovative systems including specification of marine environment-approved and aluminium fittings and products. This not only provides protection against rust and corrosion, but it also considers the whole life-cycle of the depot, with the placement of such products and systems hard to access and likely to cause disruption in the event of product failure. Steps were put in place wherever possible to ensure the longevity of the depot and its operations.


The existing shed, which contained asbestos, was innovatively incorporated into the wider redevelopment of the site, with Spencer Group designing a way of retaining the building – after expertly removing all hazardous materials – and constructing a new roof using Spencer Group’s state-of-the-art envelope and cantilever steelwork design.


As Penzance is situated in Cornwall and takes a good few hours travelling from other major UK cities such as Birmingham and London, the project wasn’t easy and straight-forward to reach to due to its location alone. With large deliveries, site vehicles, equipment and machinery going back and forth from the hugely popular tourist town, as well as being just 10metres from the shore, it was no mean feat to conduct all of this whilst the depot remained in full operation throughout.


The works at Penzance were part of a wider commitment to the South West as part of the £80m ‘National Strategic Investment Strategy’ for 2017 and beyond.

The original contract completion date was April 2018, but due to the transition of rolling stock from Old Oak Common, the contract was required to be accelerated by 17 weeks, completing by 5th December 2017. Orton Group proudly hit every major project milestone through detailed planning, hard work and dedication using not just the team involved on the ground, but from the comprehensive support available at its head office in Wombourne, Wolverhampton.

As part of the new development, there were around 80 new jobs created locally

The project, worth £5million, was completed on time and on budget

The complete installation, design and maintenance of the new Train Care Shed was completed in just 2 weeks, seeing Orton Group accelerate their works by 17 weeks

The successful completion of this project became Orton’s biggest to-date – and will stand it in great stead for ongoing major railway works across the UK

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