Accurate Data Capture Of Rail Stock

Accurate Data Capture Of Rail Stock

Physical Digital® was appointed by a client to 3D scan rolling stock, including the 319 Passenger Train, a dual-voltage electric multiple unit train, the MKIII commuter carriage and a Sleeper carriage.

To view the process of 3D scanning this rail stock, view here:

Our client focuses on new rail vehicle body and interior development, and fully engineered and manufacturing refurbishment and train redesign services.

Project objectives

In order to achieve the client's aims, Physical Digital was required to carry out a variety of 3D scanning and photogrammetry activities on a range of features both internally and externally on existing rolling stock carriages. The objectives were:

• Accurate measurement of all required surfaces using ATOS TRITOP Photogrammetry system

• Capture of scanned data using GOM ATOS Scanning System

• Use of GEOMAGIC and GOM Inspect Professional Software to align, smooth and thin all meshes to create 3D models of the rolling stock

• Export of final data into .STL file format in one agreed alignment system

3D Scanning Techniques

The following steps and systems were used to complete the project:

• Photogrammetry:

The GOM TRITOP photogrammetry system uses multiple images captured with a high resolution DSLR camera to precisely and accurately triangulate the position of reference points in 3D space. Coded reference markers are used to orientate the images together, which subsequently position the un-coded markers in a point cloud.


Calibrated optical scale bars are used to define the relative size. An understanding of accuracy can be achieved by comparing the value of the scale bars to the captured lengths.

• ATOS Scanning Software:

The optical scanning system used the photogrammetry point cloud to calculate its position on the rail carriage. Using a blue light projector and two high resolution cameras, the GOM Triple Scan sensor projects a phase shifting fringe pattern onto the surface of the object. The cameras capture several images of the projected pattern and calculate millions of points which, when combined with adjacent data, produce a high resolution point cloud.

Sleeper Train

Train Scan Data

The client required a full set of data including the collection of rolling stock carriage scans and individual component scans, and separate scanning of both the First Class and accessible WC. For the Sleeper carriage, the client required data of the individual Sleeper compartments, corridor and the wash/toilet facilities.

Project Challenges:

The process of scanning the train was carried out in fully operational train yards, alongside many other carriages which were undergoing maintenance and repair. These constraints meant that the engineers carrying out the project had to complete the work quickly and without causing interruption to the ongoing maintenance on the other trains.


Physical Digital completed the detailed capture of all necessary surfaces within the time scale. This included the interior of the trains and exterior of the carriages, a separate first class carriage and accessible WC, as well as the individual Sleeper compartments, corridor and the wash/toilet facilities. The fully portable scanning equipment ensured that the ongoing maintenance work on other trains in the yard was not interrupted.

Seat Of Train Data

The aligned meshes for all surfaces required of the carriages was delivered to the client in order for them to recreate the rolling stock as 3D models to facilitate the required accessibility upgrade and train redesign.

These same techniques can be used to ensure YOUR project is completed quickly and accurately to save you time to market. Email or speak to our expert engineers on 01483 750200 for further details.

Related Content