Canadian Pacific Railway, Parry Sound, Ontario Canada

Laser Survey Used to Validate CP Track Widening Works

Business Challenge

The proposed transportation of wind turbine tower bases from Toronto northwards to the Canadian Shield region had led Canadian Pacific Railway (CP) to undertake the widening of a 140 mile section of track through difficult terrain, where the existing rock cuttings were considered tight according to standard rail clearance envelopes.

The widening works were being undertaken in accordance with old clearance records and, for this reason, CP needed assurance that these widening works would be sufficient to allow the tower bases to pass without incident. CP was also looking to update its clearance records along this section for the processing of future over-dimensional loads. CP asked Geomatic Technologies (GT) if it could help.

Services Overview

With winter fast approaching, GT was on-site and ready to begin mapping within a very short timeframe. Using GT’s Asset Inspection Mapping System (GT AIMS), GT mobilised a CP hyrail vehicle and over the following 2 days was able to complete the 140 mile survey without interrupting mainline operations.

GT collected continuous laser, imagery and positional data along the entire railroad route. The CP deliverable to the project was a standard profile description of any fixed object which encroached upon the standard 23’x8’ box centred on the rail. Due to the heavy foliage, rock cuts and inclement weather experienced during the project, a large number of objects were found to be encroaching on the clearance box. However, thanks to the trackbased imagery recorded at speed during the survey, GT was able to select the valid encroachments and export these into a CP compatible format.

Due to the imminent shipment of the tower bases, CP requested GT to undertake another clearance analysis using just the wind turbine clearance envelope. Within 24 hours of receiving the schematics, GT had passed the new envelope through the 140 miles of track and confirmed that the shipment would make the journey without striking any fixed object on route.

A final report identified approximately 150 potential encroachment locations for CP to update its clearance records, along with an additional report highlighting several tight areas that the wind turbine tower bases would encounter.


–  GT’s rapid mobilisation and execution allowed CP to quickly validate the track widening works  that it had undertaken through the summer months.

–  Precise positioning information ensured that the locations of existing rock cuttings could be  readily identified and tested for clearance verification.

–  The clearance information from the initial survey was reused to determine whether the actual  wind turbine tower bases would pass without incident.

–  Data collection at ‘line speed’ ensured that there were no delays to mainline railroad  operations.

–  GT’s ability to work in difficult weather conditions ensured that the transportation of the wind  turbine bases was not delayed.

–  As GT collected continuous laser, imagery and positional data, composite profiles for several  major structures along the route could be delivered to CP so that it could update its clearance  database, thus delivering multiple benefits from one survey.

–  In December of 2009 the wind turbine bases traversed the 140 mile section mapped by GT  without incident.