The challenges faced by the railway industry may be self-inflicted. Thanks to rail’s fuel efficiency and low cost per tonne-mile, many companies are switching their shipping business from trucks to trains. As a result, railway operators are experiencing increased demand. This growth is good, of course. But the growing business places additional pressure on the finite and — in many locations — aging railway infrastructure. The problem is compounded by the relentless upward spiral of fuel costs and tightened environmental and safety regulations. As a result, railways need to maximise the utilisation of their fixed assets and rolling stock to move as much tonnage as possible. Achieving this goal calls for faster speeds, larger railcars and reduced downtime for maintenance and repairs. At the same time, railways must ensure safety for passengers, train crews and maintenance teams.
The information railway
Track inspection and maintenance are key components to both utilisation and safety. Effective inspection systems can directly contribute to efficient maintenance operation. By pinpointing the location and condition of maintenance needs, operators can develop tighter schedules for repair and maintenance activities. The teams know exactly where to go and what equipment and materials they will need. In order to minimise disruption to normal rail traffic, track inspection must be conducted in short time or during periods of lower train activity. Ideally, inspectors should be able to conduct inspections without affecting normal traffic.
Historically, local workers responsible for specific sections of track have conducted track inspection. But retirement and normal attrition are taking a serious toll on the ability to monitor track conditions. In order to remain effective, local knowledge must be replaced with automated, systematic approaches to gathering, maintaining and utilising information about the local conditions. Geospatial technology provides an array of solutions to these needs, including terrestrial and aerial systems.
Handheld GIS data collection systems are efficient and precise tools for inspecting and cataloguing fixed and mobile assets. Mobile mapping systems that combine GNSS with imaging and LiDAR can collect information over large areas while in motion. Because of speed and portability, these approaches can operate without disrupting normal rail traffic.
Unmanned aerial systems (UAS) are emerging as a flexible approach to gathering information along transportation corridors. A UAS uses a small, autonomous aircraft to fly routes along a railway. The system can collect imagery more frequently and at lower cost than traditional airborne photography. Data from terrestrial sensors can be combined with the aerial images to produce detailed information over large areas. By adding a geographic component to the enterprise management system, geospatial technologies provide a higher level of efficiency to resource and operations management.
One of the best ways to increase capacity is to put more cargo onto the same length of track. This can be accomplished by upgrading railcars and locomotives. The new rolling stock is larger, faster and more fuel efficient than existing trains. A primary concern is making sure that the new equipment can operate safely on existing track and rail infrastructure that may be more than one hundred years old. Here again, geospatial technology comes through.
Before making the move to larger rolling stock, railway operators must confirm that the new equipment will fit into existing corridors. This requires detailed analysis of clearances in tunnels, overpasses, stations and retaining structures. Gathering basic data for these analyses requires physical measurements of thousands of locations along each route. The technological solution begins with surveying equipment such as high-precision total stations and GNSS. These systems provide the positioning framework for inspection and analysis. In confined or congested areas, 3D scanning is an ideal method for gathering data. This may be accomplished in several ways. Scanners installed on railcars or high-rail vehicles can collect information as part of a mobile mapping system. A second approach uses scanners mounted on tripods at fixed locations. A new solution utilises a high-speed scanner mounted on a trolley that is easily moved along the track. The scanning information is processed to produce 3D point clouds of the track and surrounding features. By creating 3D models of rolling stock, designers can define clearance envelopes around the new railcars. The envelopes are added to the 3D models, where clash detection routines identify locations where clearance may be an issue.
Modern track inspection systems measure the position, gauge and cant of rails to millimeter precision. The systems combine optical instruments with precision tilt sensors and can operate on both slab and stringer/ballast track configurations. Construction and maintenance teams use the data to help ensure safe, comfortable operation of the passenger and freight cars.
The value of geospatial technology is well established for gathering and utilising position- based data for inspection and planning. Automated machine control based on GNSS or optical positioning is producing cost savings in construction of new track and facilities. Geospatial technology is helping to automate maintenance operations as well.
Rail crews use trolleys to collect detailed data on the condition of tracks. This information can be loaded into ballast tamping machines, which adjust the track and ballast to maintain the required alignment, gauge and cant. When needed, new ballast can be delivered and automatically offloaded exactly where it is needed. Similar advances in productivity can be achieved in ditch maintenance, where automated railmounted excavating machines can reduce the need for large work crews in the right of way.
The opportunities for positioning and information management are bright, and geospatial systems continue to develop in variety and flexibility. It’s an ideal fit for the complex, far-flung operations of a railway, which demands accurate positioning and related data. More importantly, the data can be converted into actionable information that is delivered directly to where it is needed for design, construction, maintenance and lifecycle planning.