Network Rail Infrastructure

ARK are committed to deliver signalling designs to both Railway Group Standards & Network Rail Company standards. This may involve simple or complex signalling principles and/or involve novel and unique design solutions to meet customer requirements with a focus on safety, and efficiency.

ARK has a proven record of delivering the signalling design aspects throughout the eight Network Rail GRIP stages as summarised below:

Output Definition

  • Signalling design input and guidance.


  • Input into the production of the Project Requirements Specification.
  • Input into the production of the Feasibility Report.

Option Selection

  • Input into the production of the Option Assessment Report.
  • Input into the production of the Option Selection Report.

Single Option Development

  • Scheme design and associated calculations.
  • Production of the signalling design element of the Design Reference Pack and
  • Design Compliance Certificate.
  • Input to the production of the Risk Register.

Detailed Design

  • Prepare, Check and Approve (CRE) NR Designs in accordance with the NR Signalling Design Handbook.

Typical Detailed Design Deliverables

  • Pre-design correlation.
  • Correlation/site survey reports.
  • Scheme Plan design.
  • Location Area Plan design.
  • Bonding plans.
  • Control Table Designs.
  • Signalling Power calculations and alterations.
  • Location/REB/Relay Room Designs.
  • Interlocking Design & Alterations – Mechanical lever frame, RRI (free-wire),
  • Geographical – GEC & Westpac.
  • Panel Work Designs.
  • Interlocking Data Design – SSI & Westlock.
  • Interfaces and fringeworks design.
  • Schematics.
  • Material schedules.
  • SAT/SOR Risk Assessments.
  • Risk Register updates.

Construction, Test & Commission

  • Operational support publications.
  • Test prints.
  • Maintenance prints.
  • Asset documentation updates.
  • Commissioning correlation documentation.
  • TiC technical support.

Scheme Hand Back

  • Updated signalling records.
  • Asset maintenance documentation.

Project Close Out