INTRO: JR Central is developing a Shinkansen infrastructure inspection train able to measure track and overhead wire parameters at 270 km/h

BYLINE: Seiichi Ishizu

Chief Engineer, Technical Research & Development Division, Central Japan Railway

KNOWN as Dr Yellow because of its bright canary paint scheme, JR Central’s Shinkansen Multiple Inspection Train is a familiar sight on Japan’s premier inter-city route between Tokyo, Osaka and Hakata. The train is used to check, measure and assess the condition and performance of the electrical systems, track and other infrastructure on the Tokaido and Sanyo Shinkansen. Running at almost the same speed as commercial Shinkansen services, it inspects the Tokyo - Hakata route about every 10 days. But its days are numbered.

JR Central has decided to replace Dr Yellow with a train more able to meet the demanding requirements of keeping in prime condition a high speed railway that is now carrying over 130 million passengers a year between Tokyo and Osaka alone.

Initial experience

The first SMIT was developed at the time of the inauguration of the Tokaido Shinkansen in 1964. Initially, overhead line and other electrical equipment was inspected using the T1 trainset, which was originally a prototype built for running trials before the launch of commercial services. The Shinkansen track was checked by a dedicated permanent way inspection car hauled by a diesel locomotive; this was able to run at up to 160 km/h, and inspections took place at night after the last service train had run.

The various inspection vehicles were later integrated into a single train known as the Shinkansen Multiple Inspection Train. This T2 derivative of the Series 0 was launched in 1974, and its livery quickly established the nickname Dr Yellow.

The T2 was able to measure a wide range of parameters. These included contact wire voltage, contact loss, the position and condition of the contact wire, the performance of signalling and safety equipment such as track circuits for the Automatic Train Control system, the LCX noise level, and track parameters such as rail level and rail irregularities. For many years the T2 train was a comprehensive and efficient means of checking the Shinkansen infrastructure, and the concept was also chosen for JR Central’s 1067mm gauge lines - a multiple inspection train called Dr Tokai was introduced in fiscal 1997 (RG 7.97 p445).


Now 24 years old, the T2 inspection train is out-of-date and nearing the end of its life. The last Series 0 trainsets on which it is based will shortly be withdrawn from service on the Tokaido Shinkansen, leaving the T2 as the only Series 0 vehicles used by JR Central. In terms of train maintenance, this has obvious disadvantages. With this in mind, JR Central decided to undertake a thorough review of its infrastructure inspection arrangements, including whether or not to continue operating a multiple inspection train.

One option was to install a number of ground-based monitoring devices to act as a nerve system for the infrastructure, but this would not allow the dynamic behaviour of contact wire and pantograph to be checked when trains are running at high speed. In terms of cost, achieving complete monitoring to detect any failure of all key equipment such as catenary and signalling would not be realistic.

JR Central concluded that the best results would be achieved by continuing to operate a high speed inspection train. By deploying this train effectively and combining it with very precise low-speed inspection runs using various maintenance cars, and supported by ground-based monitoring where required, JR Central will achieve all its inspection objectives.

Production timescale

JR Central began detailed development of the Next Generation Multiple Inspection Train in 1998, and the process is now well in hand. Production of the measuring equipment and the seven-car formation (Fig 1) begins this year, and acceptance trials and final installation of equipment is scheduled for next year (Fig 2). The train should begin operations in the summer of 2001.

The following factors determined the basic design concept: