Last month Network Rail launched a 200 km/h infrastructure measuring train designed to record the condition of the UK's busiest main lines at two-weekly intervals. The ultimate aim is to give track engineers data that is never more than 48h old

NETWORK Rail took delivery in June of a 200 km/h infrastructure inspection train. Painted in a striking bright yellow livery reminiscent of Japan's Dr Yellow inspection trains, the New Measurement Train is formed of two High Speed Train diesel power cars enclosing five other vehicles. Intended to meet the need for frequent inspection of the UK's busiest main lines, the train's 200 km/h maximum speed allows it to be pathed between the fastest inter-city services at line speed.

The NMT is part of Network Rail's programme to bring about a long-term improvement to the condition of its 16652 route-km network. The decision to acquire the train followed reassessment of the asset management regime after the derailment at Hatfield in October 2000 that was caused by a broken rail.

Until last month Network Rail's principal vehicle used to monitor the condition of high speed main lines was the Track Recording Coach. This car was built for British Rail's civil engineering department in the mid-1970s using a MkIIf coach bodyshell mounted on specially modified bogies. Although it was capable of 200 km/h, other vehicles marshalled in the recording train were limited to 145 km/h, making it difficult to obtain paths on a congested network.

Two-phase development

The NMT is being introduced in two phases. Phase One will see the existing TRC incorporated into the trainset, together with AEA Technology Rail's Tracklab, previously known as LAB5. Other vehicles in the NMT are two generator cars with messrooms and a conference coach.

The TRC has been through a major overhaul, including the installation of new recording equipment. Phase One is planned to run for six to eight months, allowing time for two newly-converted MkIII recording coaches to be prepared.

Phase One will deliver the same functionality as Network Rail's current track recording vehicles, but some additional systems have been fitted. These include the Imagemap (formerly Reeves) track geometry system known as LaserRail 3000. This is based on a laser measurement system mounted on a bogie and records twist, top, alignment, gauge, cyclic top, cant and curvature.

The TrackLab car has equipment to measure the distance between adjacent tracks, known in the UK as the 'six foot', Noisemon corrugation monitoring equipment, and a video camera to monitor the wheel-rail interface with forward and oblique angle image capture. It also carries real-time Vampire?? software to calculate ride quality.

Enhanced monitoring of rail corrugations uses a system developed by AEA Technology Rail with a sound measurement device from which various data streams can be derived, one of which identifies corrugation.

The train also has equipment to measure the strength of magnets used for the Automatic Warning System and the Automatic Power Control equipment, which cuts off and restores the power of 25 kV locomotives and multiple-units when passing through neutral sections in the overhead line.

Phase Two will see the enhancement of these systems with the addition of both contact and non-contact overhead line equipment measuring systems, rail surface defect monitoring, a load measuring wheelset and rail/ballast profiling systems. It will also see the two MkIII vehicles replace the TRC and TrackLab cars, freeing them to be reallocated to other recording duties.

The Phase Two instrumentation vehicles will have two roles. The first will be a dedicated production recording car, linking track geometry, overhead line and 'six foot' gauging measurements for the first time. The second vehicle will provide a high speed testbed which will be used to evaluate any new infrastructure monitoring systems that may be developed in the future.

To improve accuracy in the location of recorded data, the vehicles will use the latest Global Positioning Systems linked to AWS detection, vehicle tachometers, and dedicated route setting tapes. Network Rail will also be trialling the use of its asset model to locate vehicle position and to assist with identification of the recording route.

On-board facilities

The NMT has been equipped with the latest conference and office facilities. These include a full digital communications suite, scanning, printing and mobile Internet access. Optic fibre links provide internal communications throughout the train. The conference vehicle has equipment for giving presentations with a 50 inch, broadcast quality, plasma screen and has the capacity to display video and computer outputs from either of the two instrumentation vehicles.

The presentation screen can display up to 16 items concurrently, giving the ability to compare different data sets or system outputs as required by the engineers on board. This will be of particular use to track and OLE engineers, who will now be able to link in real time track geometry and overhead line outputs to forward and reverse view videos. The system also has the ability to play back any item and freeze-frame it for analysis while continuing to record, so that items of interest can be viewed or replayed during the recording run.

Current practice is to issue recording data to the track engineers in paper format with an electronic backup. The logistics of this process, considering the distance this train will run, have highlighted several ways of enhancing the data management systems. Several new software tools have been developed to verify, store and display the data. All data issued from the train will be in electronic format, with the capability to author on to a wide variety of media including CD-Rom, DVD-RAM or digital video. All data will now be subject to a two-step validation process before being released to the engineers.


Another role for the train will see track engineers from the Network Rail Regions and maintenance contractors using the on-board facilities for educational purposes.

This approach has the advantage that small groups can be brought on to the vehicle, when it is in their area, to be shown the recording systems and outputs. In the past this has been difficult to arrange as the number of visitors on board had to be restricted because space was limited. Visits to the NMT's conference facilities will allow people to observe live operation of the equipment without interfering with the recording process.


All of the UK's core main lines will be covered by the NMT in an intensive cycle:

  • East Coast Main Line from London King's Cross to Edinburgh, fast and slow tracks;
  • West Coast Main Line from London Euston to Birmingham, Manchester, Liverpool and Glasgow, fast and slow tracks;
  • Great Western Main Line from London Paddington to Bristol and Cardiff;
  • Great Eastern Main Line from London Liverpool Street to Norwich;
  • Cross-country routes linking York, Doncaster, Sheffield, Derby, Birmingham, Cheltenham and Bristol;
  • Midland Main Line from London St Pancras to Derby, Sheffield and Nottingham;
  • Doncaster to Leeds;
  • Crewe to Liverpool and Manchester;
  • Manchester to York;
  • Reading to Plymouth;
  • Swindon to Bristol Temple Meads via Bath;
  • London King's Cross to Cambridge and Kings Lynn;
  • London Paddington to Coventry via Oxford (relief lines).

The East Coast, West Coast and Great Western Main Lines will be recorded on a weekly basis, with the other routes covered fortnightly. The vehicle will operate six days a week, with two recording shifts per day. Sundays will be used for vehicle and system maintenance. This equates to more than 5470 recording-km per week or nearly 252000 recording-km per year.

With greater emphasis on track recording frequency, the opportunity exists to process data in a routine and timely way. The ultimate aim is to provide the engineers with track data that is never more than 48h old. The high frequency of recording runs on each route will enable engineers, using trend analysis, to develop more accurate models of track deterioration and to repair the track before a minor fault develops into a major one.

The benefit of this strategy will become evident over time when engineers can turn from reactive targeting of maintenance and renewals to a proactive regime.

  • CAPTION: Video cameras are mounted on the NMT's leading cars, below the cab windows, to make a visual recording of the condition of track, overhead line equipment and structures
  • CAPTION: The NMT passes Cathiron, north of Rugby, during a shakedown run on the West Coast Main Line on June 12 Photo:Chris Milner

Inspection intensive à grande vitesse

En Juin, Network Rail a pris livraison d'un train d'auscultation à 200 km/h de l'infrastructure conçu dans le but d'enregistrer toutes les deux semaines l'état des lignes les plus chargées du Royaume Uni. Dans une phase initiale, le Network Measurement Train (Train d'auscultation du réseau) aura dans sa composition la voiture d'enregistrement existante de Network Rail, mais ultérieurement, elle sera remplacée par deux voitures de mesures du type MkIII. L'une d'elles sera chargée de l'enregistrement des mesures proprement dites, l'autre étant conçue comme un laboratoire pour le futur systéme de surveillance de l'infrastructure. Le but final est de procurer aux ingénieurs de la voie des données jamais plus vieilles que 48h

Intensive Untersuchung bei hoher Geschwindigkeit

Im Juni erhielt Network Rail einen für 200 km/h ausgelegten Infrastruktur-Messzug, welcher die dichtbefahrensten Strecken des britischen Bahnnetzes in zweiw?€?chentlichen Interwallen aufzeichnen soll. In einer ersten Phase wird der neue Network Measurement Train den bestehenden Track Recording Car von Network Rail enthalten, welcher jedoch später durch zwei MkIII Instrumentenwagen ersetzt werden soll. Einer dieser Wagen wird der Produktions-Messwagen und der andere soll als Versuchsträger für neue Infrastruktur-Überwachungssysteme dienen. Das Fernziel ist, den Gleisbauern Daten zur Verfügung zu stellen, welche nie älter als 48 Stunden sind

Inspección intensiva a alta velocidad

En el pasado mes de junio, Network Rail recibió un tren de auscultación de la infraestructura apropiada para 200 km/h y diseñado con el objetivo de registrar quincenalmente las condiciones de las principales líneas m? s concurridas del Reino Unido. En una fase inicial, el Network Measurement Train (tren de auscultación de la red) incorporar? el vagón de auscultación existente de Network Rail, pero éste ser? reemplazado m? s tarde por dos coches de instrumentación de la serie MkIII. Uno de ellos ser? un coche para la auscultación rutinaria y el otro est? diseñado como un banco de pruebas para sistemas futuros de monitorización de la infraestructura. El principal objetivo es proporcionar información actualizada a los ingenieros de vía en un plazo m? ximo de 48h