Colin Johnson

Managing Director

Colin is an engineer by training and joined forces with David in 2010 to apply the pioneering research to real-time client challenges, such as dynamic pantograph gauging. He has always been driven to design new and innovative tools using the latest technologies, and to deliver them in a realistic commercial environment.

Through the family background, Gauging is in his blood and he now leads a passionate and experienced engineering and software staff, working to deliver gauging services and innovative technology to the Rail Industry.

Colin oversees all the operational aspects of the business.

Dr. David Johnson

Technical Director

David is a true innovator and technologist.

David started DGauge in 2008 as a research enterprise with a track record of introducing technology onto the Railway. His career has spanned over 40 years, covering research, engineering, management and leadership. He developed the first computerised gauging software and has been involved in the field ever since, publishing numerous software packages, papers and gauging standards. He is one of the leading experts on Gauging

David currently oversees the software development and gauging standard aspects of the business.

Steve Cartledge

Principal Engineer

Steve joined DGauge in 2015 and has over 10 years experience in the railway industry in addition to a successful teaching career.

With over 20 years experience using a range of bespoke software packages, he plays an important part in the development, validation and testing of DGauge's software tools .


Steve has worked on an extensive portfolio of projects, from on the gauging of tilting trains through the Pendolino and Voyager projects, through to more recent examples of the Class 385 (Scotrail) and East Anglia vehicle introductions.


Steve is responsible for supporting and delivering gauging assessment, with a particular focus on vehicle introduction projects

Sean Symons

Principal Engineer

Sean joined DGauge in 2014 and with 18 years experience in the railway industry, has a comprehensive understanding of rail vehicle design, development and vehicle gauging acceptance process.

Sean has an extensive portfolio of projects, including the development of UK and European Gauges and Standards, Management of the National Gauging Database (NGD), developing our DGauge vehicle library and more recently led the remodelling of the Class 153 / 155 Sprinter fleet.

Sean is responsible for delivery of a variety of vehicle modelling services and technical advise, to support Network Rail, vehicle manufacturers, regulatory bodies and train operating companies on all aspects of the vehicle gauging process.

Darren Woolstencroft

Principal Engineer

Darren joined DGauge in November 2017, and with 35 years railway experience, has a comprehensive understanding of permanent way and gauge clearance.

Darren joins DGauge of a number of vehicle introduction projects (most recently being the introduction of the Class 800 on Great Western). Darren's expertise of the GRIP process in relation to feasibility, optioneering and const analysis will be invaluable for those emabrking of vehicle introduction campaigns.

Darren is responsible for developing client scopes and delivering complex gauging assessments. He is also responsible for mentoring our junior engineers. 

Tom Coughlin

Finance Manager

Tom joined DGauge in September 2017. After completing a master's degree in engineering he became a Chartered Certified Accountant, and worked for a number of years in financial and professional services. Tom has always maintained a passion for engineering and technology, and loves working with exciting, dynamic and enterprising companies. 

Tom is responsible for the day to day financial management of DGauge, along with all aspects of statutory taxes and reporting. He is also responsible for commercial insight and support.

Ian Johnston

Programme Manager

Ian joined DGauge in October 2016 and consults on a wide variety on gauge clearance projects. He also leads the technical aspects of electrification gauging and probabilistic gauging within the engineering team. He works on projects at a variety of GRIP levels completing projects from early optioneering stages through to final detailed design and onto installation as built analysis

Alongside his technical expertise, Ian is responsible for the management of our assessment programme ensuring projects are delivered in time and within budget.


David Steward

Head of Software

David joined DGauge in February 2019 after working in the automotive and manufacturing sectors. He studied Artificial Intelligence at Birmingham University and has a passion for design and innovation.

As well as a track record for rapidly growing successful software teams, he is fascinated with emerging technologies. 

David is responsible for delivering a roadmap of new products for DGauge with a focus on world-class customer experience.

Richard Cumberlidge

Project Engineer

Richard joined DGauge in November 2017 after studying for a Masters degree in Mechanical Engineering at Loughborough University.


In his role as Project Engineer, Richard supports a wide variety of projects including transitional assessments, vehicle modelling, dynamic pantograph gauging, network modelling and route assessment using DGauge’s bespoke tools.

Jen Willison

Assistant Engineer

Jen joined DGauge in September 2016 on a Higher Apprenticeship after completing her A Levels. She is training for a Project Engineer role.


While studying for her degree, Jenni supports a wide variety of customers and projects, most notably supporting Train Operator Companies in interrogating, and interpreting the stepping risks using RouteSpace™


Andrew Burke

IT Operations Manager


Ignacio Perez

Software Engineer


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