Network Rail PACE Process: Stages & ES1–ES8 Explained

Network Rail’s PACE (Project Acceleration in a Controlled Environment) framework is used to manage the development and delivery of rail infrastructure projects.

PACE replaced the former GRIP (Governance for Railway Investment Projects) process for new projects. While GRIP remains relevant when referring to existing projects and historic project documentation, PACE provides a more flexible framework that can be tailored to the requirements of individual projects.

For organisations involved in railway engineering, design, manufacturing and construction, understanding PACE can help explain where different activities, approvals and engineering requirements fit within a project.

This guide explains the PACE process, its phases and Engineering Stages, how PACE differs from GRIP, and where railway equipment and engineering services can form part of a project.

What is PACE?

PACE stands for Project Acceleration in a Controlled Environment.

It is Network Rail’s project delivery framework for infrastructure investment projects. PACE was introduced to replace GRIP and provide a more flexible approach to project development, design and delivery.

Unlike a rigid sequence of activities, PACE allows projects to be managed according to their individual requirements. Network Rail’s guidance states that activities associated with different milestones can overlap where appropriate.

This means that PACE should not be viewed simply as a checklist where every activity must be completed one after another.

Instead, the framework provides a structure for controlling project development while allowing the approach to be adapted to the scope, complexity and requirements of the individual project.

Why did Network Rail replace GRIP with PACE?

GRIP provided Network Rail with an eight-stage framework for managing railway investment projects, from Output Definition through to Project Closeout.

PACE replaced GRIP with a more flexible control framework.

One of the stated benefits of PACE is that it allows control points and project activities to be tailored to the requirements of the project.

This is particularly relevant to railway projects, where the level of design, assurance, engineering, approvals and construction required can vary considerably depending on the project.

PACE is therefore not simply a renaming of the eight GRIP stages. The two frameworks have different structures, and the relationship between individual GRIP stages and PACE Engineering Stages is not a direct one-to-one conversion.

How does the Network Rail PACE process work?

Network Rail’s current guidance presents PACE around an initial Project Initiation step followed by four main phases:

1. Project Initiation
2. Strategic Development & Project Selection
3. Project Development & Design
4. Project Delivery
5. Project Close

The first step establishes the project and the arrangements needed to take it forward. The four subsequent PACE phases contain the Engineering Stages that provide key points of control and development.

Project Initiation

Project Initiation establishes the foundations for the project. This includes putting the appropriate project team and management arrangements in place and preparing the Project Management Plan.

It is important to distinguish Project Initiation from ES1. ES1 is the first Engineering Stage and sits within the following Strategic Development & Project Selection phase.

The Four PACE Phases Explained

Phase 1: Strategic Development & Project Selection

The first formal PACE phase is Strategic Development & Project Selection.

This phase is concerned with establishing what the project needs to achieve, understanding the constraints and developing the preferred option.

It contains three Engineering Stages:

ES1 – Client Requirement Defined and Baselined

ES1 establishes the client’s requirements for the project and provides a baseline against which the project can be developed.

At this point, the project team needs to understand what the project is intended to achieve and what requirements it needs to satisfy.

ES2 – Constraints Identified and Project Feasibility Confirmed

ES2 focuses on understanding the constraints that could affect the project and confirming that the proposed approach is feasible.

Depending on the project, constraints could include engineering requirements, operational considerations, site conditions, access, environmental considerations, existing infrastructure and other project-specific factors.

ES3 – Single Option Identified and Endorsed

ES3 is reached when a single option has been identified and endorsed.

The project can then move into more detailed development and design.

Phase 2: Project Development & Design

The second PACE phase is Project Development & Design.

This is where the selected project option is developed into an approved design suitable for construction.

It contains two Engineering Stages:

ES4 – Design Standards Approved and Approval in Principle

At ES4, the design is developed to the point where the relevant design standards have been approved and Approval in Principle (AiP) has been achieved.

The precise design activities and approvals required will depend on the project.

For railway engineering projects, this can involve the development and coordination of civil, signalling, electrical, power and other technical requirements.

ES5 – Construction-Ready Design Approved

ES5 represents approval of the construction-ready design.

By this point, the design needs to provide the information required to allow the project to proceed into delivery.

This is where detailed engineering and equipment requirements can become particularly important.

For example, a signalling or railway power project may require detailed designs for equipment housings, electrical assemblies, cable connections or other trackside infrastructure before equipment can be manufactured and installed.

Engineering Design for Railway Projects

The design stage is where engineering decisions made earlier in the project are translated into detailed designs and specifications.

For projects requiring specialist railway equipment, this can include determining:

• Equipment requirements
• Enclosure and housing requirements
• Internal layouts
• Cable and termination arrangements
• Power distribution requirements
• Environmental and installation requirements
• Testing requirements
• Manufacturing information
• Documentation required for installation and handover

RSP provides engineering design alongside its manufacturing and testing capabilities, allowing designs for railway equipment and enclosures to be developed with the manufacturing process in mind.

Find out about RSP Engineering Design

Phase 3: Project Delivery

The third PACE phase is Project Delivery.

This phase covers the delivery of the project in accordance with the approved requirements and includes construction, testing and commissioning activities.

The Engineering Stage associated with Project Delivery is:

ES6 – Construction Complete

ES6 represents completion of construction.

Network Rail’s guidance also identifies testing and commissioning and the asset entering service as part of the objectives of the Project Delivery phase.

For projects involving railway signalling and power infrastructure, delivery may involve the manufacture, factory testing, transportation and installation of a wide range of specialist equipment.

What equipment can be required during a railway project?

The equipment required will depend entirely on the scope and design of the individual project.

For example, a signalling project may require equipment such as:

• Trackside Connection Boxes (TCBs)
• Signalling Location Cases (LOCs)
• Signalling equipment racks
• Relocatable Equipment Buildings (REBs)
• Plug couplers
• Component boards and other signalling components

Railway power projects can involve equipment such as:

• Distribution Network Operator (DNO) cubicles
• Functional Supply Points (FSPs)
• Principal Supply Points (PSPs)
• Auxiliary Supply Points (ASPs)
• Lighting control cubicles
• Other bespoke rail power cubicles and enclosures

These products are not required on every PACE project. Their inclusion depends on the engineering design, project scope and infrastructure being delivered.

Trackside Connection Boxes

Trackside Connection Boxes, also known as Dis Boxes or TCBs, can be used to provide protected points for connecting and terminating signalling and other trackside electrical circuits.

Depending on the application, a project may require different enclosure sizes, mounting arrangements, terminals and internal configurations.

RSP designs and manufactures Trackside Connection Boxes for signalling and E&P applications, including solutions for projects involving axle counters, level crossings and other trackside equipment.

View RSPs Trackside Connection Boxes

Signalling Location Cases

Signalling Location Cases provide protected housing for equipment installed alongside the railway.

A project may require empty location cases, partially fitted cases or fully configured equipment enclosures depending on the design and installation requirements.

Location cases can accommodate a range of signalling and associated equipment, with the internal layout designed around the requirements of the particular project.

RSP designs and manufactures railway signalling location cases in materials including mild steel, stainless steel and GRP, with bespoke internal configurations available.

View RSPs Signalling Location Cases

Relocatable Equipment Buildings

Larger signalling or power installations may require a building or enclosure capable of housing multiple pieces of equipment. Relocatable Equipment Buildings (REBs) are used to house railway signalling, power, communications and associated equipment.

Because REBs can be prepared away from the railway before being transported to site, they can form part of a project delivery strategy where off-site manufacture and testing are appropriate.

RSP designs and manufactures REBs to project and client requirements, with options for different equipment and internal configurations.

View RSPs Relocatable Equipment Buildings

Railway Power Equipment

Railway projects can also require electrical distribution equipment to provide power to signalling, stations, level crossings, lighting and other infrastructure.

The exact equipment depends on the project’s electrical design and requirements.

DNO Cubicles

DNO cubicles provide housing for electrical distribution equipment associated with railway infrastructure.

They can be used across signalling, E&P, station, level crossing and other railway power projects.

RSP designs and manufactures standard and bespoke DNO cubicles, including complete design, build and testing services.

View RSPs DNO Cubicles

Functional Supply Points and Principal Supply Points

Functional Supply Points and Principal Supply Points form part of railway power distribution infrastructure.

Where required by a project’s design, these assemblies can be designed and configured to suit the electrical requirements of the installation.

RSP designs and manufactures FSPs, PSPs and ASPs for railway applications, with bespoke configurations available.

View RSPs Functional Supply Points

View RSPs Principal Supply Points and Auxiliary Supply Points

Lighting Control Cubicles

Projects involving stations, platforms, level crossings or other railway lighting infrastructure may require dedicated lighting control equipment.

Lighting control cubicles can house the switchgear, protection and control equipment needed to manage railway lighting circuits.

RSP designs and manufactures standard and bespoke railway lighting control cubicles and can provide factory-built and tested assemblies.

View RSPs Lighting Control Cubicles

Phase 4: Project Close

The final PACE phase is Project Close.

This phase covers the activities required to complete the project and transfer the completed asset into its operational environment. It contains two Engineering Stages.

ES7 – Project Demobilised and Handed Back to Sponsor

ES7 covers project demobilisation and hand back to the Sponsor.

The project team begins closing down the systems and arrangements associated with delivering the project.

ES8 – Formal Project Closeout

ES8 represents formal project closeout.

This includes activities such as settling contractual accounts, transferring warranties to the maintainer where applicable and completing the formal closeout process.

Documentation and records generated throughout the project can therefore remain important after physical construction has finished.

What are the PACE Engineering Stages?

The eight Engineering Stages, ES1 to ES8, provide key points of development and control within the four PACE phases.

PACE phase	Engineering Stage	Key outcome
Project Initiation	—	Project team and management arrangements established
Strategic Development & Project Selection	ES1	Client requirement defined and baselined
	ES2	Constraints identified and project feasibility confirmed
	ES3	Single option identified and endorsed
Project Development & Design	ES4	Design standards approved and Approval in Principle
	ES5	Construction-ready design approved
Project Delivery	ES6	Construction complete
Project Close	ES7	Project demobilised and handed back
	ES8	Formal project closeout

The Engineering Stages should not be interpreted as a rigid sequence of activities that must always happen independently.

Network Rail’s guidance states that activities associated with individual milestones can overlap where appropriate. The way a project progresses through PACE therefore depends on its particular requirements.

Does PACE Have to Be Followed Sequentially?

Not necessarily. One of the important differences between PACE and the former GRIP process is the flexibility built into the framework.

Network Rail explains that, although PACE milestones can be shown sequentially, this sequence is not mandated and activities required to deliver individual milestones can overlap.

This allows project teams to structure work around the requirements of the individual project rather than applying exactly the same sequence to every scheme.

The level of flexibility will depend on factors such as project scope, complexity, engineering requirements, approvals, risk and the operational environment.

PACE vs GRIP: What’s the Difference?

GRIP was Network Rail’s former eight-stage framework for managing railway investment projects.

The eight GRIP stages were:

1. Output Definition
2. Feasibility
3. Option Selection
4. Single Option Development
5. Detailed Design
6. Construction, Test and Commissioning
7. Scheme Hand back
8. Project Closeout

PACE replaced GRIP for new projects.

However, PACE should not be viewed as a simple renaming of the eight GRIP stages.

The frameworks have different structures and PACE provides greater flexibility around how project activities are planned and controlled.

Network Rail documentation does provide comparisons between PACE Engineering Stages and GRIP stages, but the relationship is not always one-to-one.

For example, Network Rail documentation identifies ES1 as broadly corresponding to GRIP 1, ES2 to GRIP 2/3 in some technical contexts, ES3 to GRIP 4, ES4 to GRIP 5 and ES6 to GRIP 6. ES7 and ES8 broadly correspond to GRIP 7 and GRIP 8.

These comparisons should therefore be treated as guidance rather than a direct conversion between the two frameworks.

Is GRIP Still Used?

PACE replaced GRIP for new Network Rail projects. However, GRIP has not simply disappeared from the railway industry’s vocabulary.

Existing and ongoing projects may still have been developed under GRIP, while historic project documentation can continue to refer to the eight GRIP stages.

This means both GRIP and PACE terminology can still appear in railway project documentation.

For anyone working with existing railway infrastructure projects, understanding the former GRIP process therefore remains useful.

What Does PACE Mean for Railway Equipment Suppliers?

PACE does not prescribe a particular supplier or product. However, the framework provides a useful way of understanding where engineering, manufacturing and equipment requirements can arise during a railway project.

During Project Development & Design, equipment requirements can be established and incorporated into the construction-ready design.

During Project Delivery, the specified equipment can then move through manufacturing, testing, installation, testing and commissioning activities as required by the project.

For equipment suppliers, this makes early involvement in the design process particularly relevant where bespoke equipment, specialist enclosures or project-specific configurations are required.

Design, Build and Testing for Railway Projects

RSP supports railway projects with in-house engineering design, manufacturing and testing.

Depending on the project requirements, this can include signalling equipment, trackside enclosures and railway power equipment.

RSP’s railway product range includes signalling equipment such as Trackside Connection Boxes, Location Cases, REBs, equipment racks and specialist signalling components, alongside rail power equipment including DNO cubicles, FSPs, PSPs and lighting control cubicles.

Find out about RSPs Railway Products

The benefit of bringing design and manufacturing capabilities together is that equipment can be developed with both the engineering requirements and manufacturing process in mind.

For project-specific equipment, this can include bespoke layouts, factory assembly, testing and documentation before equipment is delivered to site.

RSP and PACE Projects

RSP’s existing GRIP and PACE-related content references the company’s involvement in the Okehampton project, which was delivered using the PACE approach, including the supply of DNO cubicles.

Frequently Asked Questions About Network Rail PACE

What does PACE stand for in Network Rail?

PACE stands for Project Acceleration in a Controlled Environment. It is Network Rail’s project framework for infrastructure investment projects and replaced GRIP for new projects.

What are the PACE phases?

Network Rail’s current guidance presents Project Initiation followed by four main PACE phases:

• Strategic Development & Project Selection
• Project Development & Design
• Project Delivery
• Project Close

The Engineering Stages ES1–ES8 are distributed across those four phases.

What are ES1 to ES8?

ES1 to ES8 are the Engineering Stages used within the PACE framework.

They cover key points from defining and baselining the client requirement through feasibility, option selection, design, construction, handback and formal project closeout.

Has PACE replaced GRIP?

Yes. Network Rail has replaced the GRIP process with PACE for new projects.

GRIP remains relevant when referring to existing projects and historic project documentation.

Is PACE faster than GRIP?

PACE was developed to provide a more flexible project control framework and to help improve the efficiency of project development and delivery.

However, PACE does not guarantee that every project will be delivered faster. Project timescales depend on the scope, complexity, engineering requirements, approvals, access, procurement, construction and other project-specific factors.

Does PACE have eight stages?

PACE has eight Engineering Stages, ES1 to ES8, rather than eight main project phases.

These Engineering Stages sit within the four main PACE phases following Project Initiation.

Can PACE activities overlap?

Yes. Network Rail guidance states that activities associated with individual PACE milestones can overlap where appropriate.

PACE is intended to provide a flexible framework that can be adapted to the requirements of the individual project.

What is the difference between PACE and GRIP?

GRIP was Network Rail’s former eight-stage project framework. PACE replaced GRIP and provides a more flexible framework for controlling project development and delivery.

The two frameworks should not be treated as direct one-to-one equivalents, although Network Rail documentation provides comparisons between GRIP stages and PACE Engineering Stages.

Conclusion

PACE is now an important part of understanding how Network Rail infrastructure projects are developed and delivered.

Rather than replacing GRIP with another rigid sequence, PACE provides a more flexible framework built around Project Initiation, four main phases and eight Engineering Stages.

For organisations involved in railway engineering and supply, understanding where design, equipment specification, manufacturing, testing and delivery fit within the process can help provide a clearer picture of how projects progress.

The equipment required will vary from project to project, but specialist signalling and power infrastructure can form an important part of the design and delivery stages.

For more information about RSP’s railway signalling and power products, explore our range of railway products and see how our design, manufacturing and testing capabilities support rail infrastructure projects.