Rail Clearance Upgrade Toowoomba

Client: BMD

Year Completed: 2017

The rail line which links Toowoomba with Brisbane has 11 heritage tunnels dating back to the 1860’s. International shipping companies are transitioning between 86 to 96 containers which means the tunnels are too small to accommodate the larger containers. Because they are heritage listed the majority of the tunnels need to remain untouched, therefore Queensland Rail has proposed to lower the floor and rail alignments.

BMD were engaged as the principal contractor and WSP-Parsons Brinckerhoff as the design team. The tunnel floor needed to lowered enough to provide sufficient clearance while minimising the impact on storm water and other underground services.


  • Re-establish survey control along rail corridor
  • 3D Laser Scanning of the 11 rail tunnels including the approaches
  • Create a precise 3D mesh of each tunnel
  • Prepare & host TruView Global panoramic pointcloud viewer
  • Detail surveys to QLD Rail specifications
  • Survey drainage for hydraulic investigation
  • Underground service location

Full access to the tunnels was provided during a 48 hour track closure. To capture all of the information within this small window, Bennett + Bennett mobilised a specialist team of 8. An integrated laser scanning and detail survey approach was able to speed up acquisition and provide reliable data that ensured no further site visits were required.

High quality deliverables were supplied within 2 weeks. All pointclouds, 3D meshes, TruView Global, video and detail surveys were issued within 6 weeks.


  • Laser Scanning / High Definition Surveying
  • Surveying

Analysing the rail vehicle clearance throughout the construction.

The challenge was to analyse the rail vehicle clearance at critical times throughout the construction using spatial information. In order to accomplish this we had to establish a method to undertake these complex clash detection calculations in the shortest possible time, whilst having the utmost confidence in the results. Our spatial team formulated a unique algorithm which took into consideration different train sizes, the geometry of motion, combinations of kinematic envelopes and curve overthrows at all cross-sections along a vehicle, as the vehicle moved along the track.

These variables were then analysed against the previously captured site spatial information using the as-constructed rail alignments and terrestrial laser scans of the tunnels. The algorithm generated an automated verification report and included diagrams that were prepared within minutes of receiving the as-constructed rail alignment from site. The report could then be signed of and issued by Registered Surveyors within an hour.


  • Formulation of a digital algorithm so that complex calculations to determine clash detection could be solved quickly and accurately.


  • Laser Scanning / High Definition Surveying
  • 3D Modelling / Visualisation
  • Surveying

Year Completed: 2018 – 2019