THIS SUMMER, lineside residents around the Austrian city of Linz could have been woken by the strange sight of a blue and silver inspection vehicle trundling by, festooned with floodlights and cameras, as well as a host of advanced measurement systems. The twin-unit Track Geometry Car 4 spent a week undertaking dynamic performance and ride quality trials around the ÖBB network before delivery to New York City Transit.

Along with sister unit TGC3, dispatched from Linz earlier this year, the Plasser-built inspection vehicle will enable NYCT to improve its monitoring of infrastructure condition on the New York subway network, replacing a pair of older measurement cars.

As well as the video cameras which record and analyse the condition of the tunnels and other infrastructure, the two new Track Geometry Cars are equipped for ultrasonic rail testing on one vehicle and dynamic assessment of track geometry on the other, which features a third bogie to carry the measurement heads.

Plasser uses an inertial navigation system to support its non-contact measuring systems, backed up by a 3D laser gyroscope for speeds below 30 km/h. Together these provide an absolute image of the track alignment, which can then be analysed by onboard computer systems for chord lengths of up to 100 m.

TGC4 is equipped with further lasers and video cameras for non-contact measurement of the track gauge and rail profiles, for both running rails and the 750 V DC third rail.

Over the years, Linz residents have become used to seeing a melange of inspection and maintenance machines being tested on the local rail network. As one of the largest employers in Austria's industrial heartland, Plasser & Theurer enjoys a good relationship with ÖBB.

Sitting alongside TGC4 in Plasser's Linz plant at the end of August was a wide variety of track maintenance and inspection equipment, which General Manager for Marketing & Technical Sales Ing Rainer Wenty says reflects the company's breadth of experience in the market.

Two Series 09-3X continuous-action tampers were due to be delivered to BNSF in the USA and Network Rail in the UK. Outside on the test track was an SSP-203K ballast regulator for use in South Korea and a Unimat Compact 08-32 tamper for a Spanish maintenance contractor designed to operate on three gauges - 1668, 1435 and 1000 mm. This has automatically-adjustable tamping heads, which can be positioned to suit the differing rail seat positions, but Wenty explains that the bogies have to be changed in a workshop.

To accommodate demand, Plasser also assembles machines at a former shipyard elsewhere in Linz, where a large multi-function ballast cleaner is taking shape alongside a metre-gauge dynamic stabiliser for use in Malaysia. Other assembly work has been subcontracted to partner company Robel in Freilassing, which is perhaps better known for its range of small machinery and tools including the semi-automatic torque wrenches used to adjust German-style bolted track fastenings. Robel is currently delivering 10 of its innovative Mobile Maintenance Units to ÖBB, as well as a series of multi-purpose track vehicles for DB, fitted with seven-person cabs and a flatbed carrier with a hydraulic crane.

Faster and smarter

Whilst there is steady demand for medium-sized equipment, Wenty confirms a clear trend towards bigger and more powerful multi-function machines. With infrastructure managers under pressure to keep lines open every day to accommodate growing traffic, he says the driving force in maintenance technology is the need to set up on site rapidly, do more work more quickly, and hand back the line to the train operators as soon as possible.

Machines like the RPM-RS-900 ballast cleaner and formation renewal train are typical of the new generation, he suggests. Although the capital cost may be high, the higher productivity and reduced disruption will pay back the investment very quickly. Other combinations proving popular with customers include the Tamping Express family, which combine a continuous-action tamper-leveller-liner with a dynamic stabiliser and various multi-function track renewal machines.

Many of the machines currently being built are fitted with the latest version of Plasser's Computer Measurement System ALC, which allows the unit to assess the condition of the track before treatment, analysing the geometric profile and calculating the work required to restore an optimum alignment. CMS can then be used at the end of the run to cross-check the final output, recording each step of the data for off-line analysis and record keeping.