Rail Infrastructure Upgrade – Isle of Wight Island Line

Railway infrastructure upgrades often require careful coordination between signalling systems, power infrastructure and wider railway engineering disciplines. The Isle of Wight Island Line Upgrade formed part of a programme to modernise the existing network ahead of the introduction of Class 484 rolling stock, requiring significant infrastructure works across multiple engineering systems.

The project involved upgrading the island railway through improvements to track infrastructure (PWay), re-signalling, civil engineering works, electrification and power (E&P), plain line track and switches and crossings (S&C). The programme was delivered within a challenging eight-month window from contract award through to commissioning.

Project Delivery and Site Management

OSL managed all site compounds and operational setups required to deliver the works across the island network. This included establishing welfare facilities, site compounds, surveys and design coordination across the project lifecycle.

Managing the programme within a constrained timeframe required careful coordination of engineering activities across multiple disciplines, ensuring that infrastructure works, signalling upgrades and power systems integration progressed efficiently within the available possession windows.

Signalling Design and Infrastructure Modernisation

A central component of the project was a route-wide signalling upgrade designed to improve reliability and operational flexibility across the network.

OSL delivered full signalling design, installation, testing and commissioning services, replacing the legacy Route Relay Interlocking (RRI) system with a modern Solid State Interlocking (SSI) system. This transition provided a more flexible and reliable signalling architecture capable of supporting the operational requirements of the upgraded railway.

As part of the signalling works, OSL installed a new signalling panel, SSI cubicle and 18 location cases alongside eight new signals. The scheme also included the installation of 17 new Train Protection and Warning System (TPWS) axle counters using Frauscher technology to enhance train detection capability across the route.

Testing, Commissioning and System Integration

All signalling infrastructure was subject to a comprehensive testing and commissioning programme delivered by OSL in accordance with the project specification and approved scheme plan.

The programme included in-house testing and commissioning activities covering signalling systems, integration with track infrastructure and coordination with associated civil engineering works. This ensured the upgraded railway signalling systems could be safely brought into service following completion of the installation phase.

Points Operating Equipment Integration

Operational flexibility across the network was further enhanced through the integration of Points Operating Equipment (POE) at Brading and Sandown.

This involved installing two new HW point machines at Brading together with upgrades to two existing units at Sandown. Factory Acceptance Testing (FAT) was undertaken prior to installation to verify equipment performance and ensure compliance with operational requirements before deployment on site.

Electrification and Power Infrastructure Upgrades

In parallel with the signalling works, OSL delivered key electrification and power upgrades to support the modernised railway systems.

The E&P scope included the design, installation and entry into service of two new 650V Class II feeders together with associated power supply infrastructure. This included a stand-alone mini-PSP alongside combined Class II Functional Supply Point (FSP) and location cases to support the upgraded signalling systems.

All electrical power design calculations were developed using ETAP power system analysis software, ensuring the network could reliably support the new infrastructure and the operational requirements associated with the introduction of Class 484 rolling stock.

Integrated Railway Infrastructure Delivery

The Isle of Wight Island Line Upgrade demonstrates the importance of integrated engineering delivery across signalling systems, electrification and rail infrastructure disciplines.

By coordinating signalling design, infrastructure installation, electrification works and testing and commissioning activities within a compressed programme window, OSL supported the successful modernisation of the island railway network and the introduction of new rolling stock.

OSL Global provides multidisciplinary engineering capability across railway signalling design, electrification and power systems, telecommunications, testing and commissioning and integrated rail infrastructure delivery. You can get in touch with a member of our team, here.