Updating Scotland’s structure gauging database faster and safer with innovative RILA® technology

The challenge

Scotland's railway system is extensive, stretching from the Borders to Thurso in the far northeast. It makes up more than 17 % of Britain's railways, facilitating a staggering 107 million passenger journeys every year.

When Network Rail decided to update its asset gauging database for the Scottish network, the shear physical size meant using conventional ground survey methods would be too time-consuming. They needed an innovative solution that could cover large distances without compromising data accuracy or the safety of staff.

Solution

To tackle this challenge, Network Rail opted to use our state-of-the-art train mounted RILA® monitoring system. This cutting-edge technology had already been successfully used for similar work in Wales and the Western Region and could provide engineering-accuracy Geo-data on the rail corridor, whilst minimising disruption to train services and limiting people on or near the track.

Why gauging matters

Gauging determines the spatial clearance between trains and structures on the railway. This ensures trains can safely pass one another and travel through tunnels, bridges, stations and other lineside structures with sufficient clearance.

The scope of this project included a wide range of different topographies and environments, from the busiest suburban railway in Glasgow to the remote single-track sections of the Scottish Highlands.

Mapping track and corridor conditions

The timing of our work (Autumn 2021) coincided with the gradual recovery from Covid-19 and initially RILA® was operated from dedicated freight trains with pre-planned paths. However, as restrictions eased, RILA® was connected to Scotrail passenger trains operating within their regular timetable. Traveling at linespeed, RILA® gathered survey data of the tracks and immediate surroundings.

Through millions of data points – collected using downward facing track scanners, lidar laser scanners and live video footage - we’re able to map the position and condition of the track and any object in the railway corridor based on absolute and relative track geometry.

Delivered through an intuitive and secure web portal, we integrate 2D and 3D data to provide a Track Twin - a dynamic 3D model - of the railway corridor. This allows Scotland’s route engineers and asset managers to view their acquired data in a desktop environment - particularly pertinent considering the network covers remote and difficult-to-access areas.

Plan for the future

Although, the primary purpose of the project was to gather data for gauging applications, the data is also suitable for a range of other engineering design and asset management applications including:

• Measurement of current overhead line electrification (OLE) componentry and design of future electrification schemes

• Track geometry and gradient

• Determination of heights and staggers

• Vegetation analysis

• Topographical feature extraction of structures, lineside buildings, and objects

• Signalling and track ballast measurements.

The widespread use of RILA® data across many disciplines supports our “survey once, use many times” mantra.

Supporting sustainability

Having rich survey data and asset information, such as those provided by our Track Twin, will support the design challenges that lie ahead for Network Rail.

The Scottish Government considers rail electrification to be an essential part of its national transport strategy. Its Scottish Rail Services Decarbonisation Action Plan, launched in July 2020, will decarbonise all rail passenger services by 2035.

But Scotland’s electrification is challenging. There are significant clearance issues throughout the network given the topography and geography including the Highland Main Line and even the iconic Forth Rail Bridge and power supply to remote areas to support electrification is a major obstacle to be overcome

Survey data will be an invaluable tool to help Network Rail understand the challenges of electrifying Scotland's railways and to develop the best possible solutions.

Innovative highlight

A manual gauging survey normally collects readings at 5 m intervals, as a result, areas may be missed if it is located at an intermediate position between the 5 m readings. However, RILA® monitoring system involves a continuous scan of the surrounding environment. Areas that may have been missed will now be recorded, and any clearance issues identified in the composite sections.

In addition to the 5 m composite sections, profiles will be created to identify the tops of platform ramps. Six-foot passing clearances are calculated from the RILA® track scan data where the absolute real-world position of each track is used to calculate the interval between adjacent tracks.

Impact

Our Track Twin offering provided significant benefits:

• Increased safety and lower risks with fewer field visits needed to plan, scope and inspect the railway corridor

• Full control and easy access to georeferenced track data means fewer incidents and lower costs

• Optimised railway operations, proactive decision-making and improved engineering work via an up-to-date and accurate digital twin of the entire railway network

Facts and figures

The Scotland gauging survey delivered gauging data pertaining to:

• 669 station platforms

• 110 tunnels

• 7,823 bridges and viaducts

• 3,203 signals

• 15,926 retaining walls.

In total, we supplied over 187,062 gauging profiles for direct input into the National Gauging Database, which identified more than 5,000 previously unrecorded structures.

Final data is output and delivered in accordance with the NR/L2/TRK/3203 gauging standard.

Watch the video below to see RILA® in action: