Over 9000 trade visitors from 50 countries attended the Railtex 2000 exhibition at Britain's National Exhibition Centre near Birmingham. Many of the exhibitors used the event to announce new contracts or launch innovative products

Centrepiece of the Alstom stand was a Class 458 EMU from the company's Juniper range being supplied to SouthWest Trains. On December 12 Railtrack issued a full safety case for 12-car operation of Class 458 units on its 750 V third-rail network and an Interim certificate for the Class 334 version for 25 kV 50 Hz routes.

Alstom Transport, Great Britain. Reader Enquiry Number 135

Traveller economy Turbostar

A LOW-COST version of the Adtranz Turbostar DMU series now in use with six British train operators was unveiled by Adtranz at Railtex. Intended to replace the bus-bodied Pacer railcars acquired by British Rail in the 1980s, the Traveller is designed for urban and short-distance regional routes. The basic model, aimed at urban routes supported by local Passenger Transport Executives, is expected to be around 15% cheaper than a full-specification Turbostar.

The Turbostar Traveller has the same bodyshell of bolted aluminium extrusions and a crash-resistant steel cab. It is powered by a MAN 338 kW engine, giving a top speed of 120 km/h, compared to the Turbostar's 160 km/h. It retains the same Voith transmission, and the proven Series 3 bogies. but has a new range of auxiliary equipment. The cars are designed to run up to 4800 km between refuelling, allowing intensive diagramming. The air-conditioned vehicles have electric-operated sliding-plug doors, two wheelchair spaces per train, and clear signage complying with Britain's latest disabled accessibility regulations.

The modular interior layout is designed for flexibility, and the specification includes a number of options to meet the requirements of either the individual operators or the sponsoring PTEs. These include bicycle facilities, luggage racks, and tables. The basic unit is intended as a two-car set, but a centre car will also be available for busy routes.

Adtranz UK Ltd, Great Britain

Reader Enquiry Number 136

Self-breaking windows

ROLLING stock leasing company Angel Trains has applied for Railtrack approval to conduct passenger trials with an innovative emergency evacuation technique being developed by Pickersgill-Kaye. The equipment is due to be fitted to one of the Mk IV coaches in a GNER IC225 push-pull trainset.

To facilitate faster evacuation, built-in hammers are used to break the toughened double-glazed windows. Typically four exit windows would be located in each coach, at the 1/4 and 3/4 positions on each side. At present, passengers must locate an emergency hammer in a sealed box, and then use this to break the window. But sealed double-glazed units are difficult to break unless hit in the right spot.

The Pickersgill-Kaye design uses a spring-loaded hammer built into the vehicle bodyside alongside the exit window. The operating handle is protected by a sliding cover and alarmed to prevent misuse. When activated, the hammer shatters both panes of toughened glass, allowing the passengers to push out the glass fragments and effect their escape. Using a standard window helps maintain vehicle integrity in the event of the coach overturning.

Pickersgill-Kaye, Great Britain

Reader Enquiry Number 137

ITALIAN Railways has started testing a microwave radar-based obstacle detector developed by Siliani Harmon. Installed on three crossings in the southeast of the country, it is seen as a cheaper alternative to manual supervision using CCTV.

Drawing 10mW, the sensors are armed whenever the crossing barriers are activated. They can detect obstacles of sizes down to 0·5m, and use a long sampling cycle to avoid picking up cars or people moving clear of the protected area. The carrier frequency is less than 10GHz, which prevents problems with rain and allows the detectors to be used in all weathers, including fog and snow.

There are two microprocessors for redundancy, and the failsafe electronics carry out self-diagnostic tests.

Siliani Harmon SpA, Italy

Reader Enquiry Number 138

Westlock in two years

WESTINGHOUSE SIGNALS unveiled its 'fourth-generation' Computer-Based Interlocking at Railtex. Intended as the successor to the company's Solid State Interlocking technology developed with British Rail in the mid-1980s, Westlock is expected to be approved for use on Railtrack in 18 months to 2 years. Independent safety assessments have been undertaken, and Westinghouse is preparing to start the ISRP approval process.

Westlock uses a similar 2-from-3 voting arrangement to SSI, but each processor runs two different sets of programs and data, giving extra redundancy. The 50MHz processors are drawn from a suite of process control equipment developed for the oil and gas industry by another Invensys company, Triconex. This is approved to Safety Integrity Level 3, and Westinghouse is working with Triconex to achieve SIL4 for rail use.

As with SSI, if one processor disagrees with the other two, it is shut down and the interlocking continues as 2-from-2 until a replacement can be fitted. A major advantage of Westlock is that the defective processor can be replaced without shutting down the interlocking. Another key difference from SSI is that there is no memory chip for location-specific data; this is all held in Eprom, allowing a standard 'blank' module to be used in any location. When it is inserted, the data and programs will be copied across from the other two processors automatically.

Westlock is designed to be backwards-compatible with SSI location equipment, and Westinghouse has developed a second processor unit to 'decode' the high-speed signals from the interlocking's wide-area network and output them over a serial data link. Using these in remote locations would allow faster communications over the WAN trunk; in the longer term the company will develop CBI object controllers to succeed the SSI modules.

Maximum cycle time for a Westlock interlocking is put at 165ms, although this is unlikely to be reached in practice. At Railtex the demonstration CBI was running a copy of the Edinburgh Waverley installation (which requires three SSIs) and this only half-filled one suitcase-sized interlocking, achieving a cycle time of 39ms.

Using a Windows NT platform, Westlock is designed to interface with Westinghouse's existing Westcad signalling workstations. Layout design and modifications can be undertaken using Plans software, which feeds into an Automatic Data Generation program to prepare the control logic. The modular structure enables layout changes to be developed and tested off-line, with the revised data and programs being downloaded to the interlocking via a docking port in each rack.

Westinghouse Signals Ltd

Reader Enquiry Number 139

Jetrain takes off

BOMBARDIER Transportation announced on November 21 that it is developing a gas turbine trainset that could replace the British diesel IC125 high-speed trains. First Great Western has been looking for two years at a 225 km/h gas turbine trainset to replace its HSTs, which will be 30 years old by 2006.

Bombardier's Jetrain is not based on the prototype 5000hp gas turbine Non-Electric Locomotive, (RG 4.00 p219), which made its inaugural test run at La Pocatière last month. Instead the company has teamed up with French gas turbine builder Turbomeca to produce an HST-style trainset, with eight or nine coaches between twin 3200hp Bo-Bo power cars. Each power car would have two Makila II 1600hp turbines, each driving two axles on one bogie through a Voith hydraulic transmission. This combination is identical to that used in the SNCF Turbotrains built in the 1970s.

In addition, each power car would have a 500 kW diesel generator set to provide auxiliary electrical power. These could also provide power for depot movements, using an electric motor on the hydraulic transmission. Weight of the power car is quoted as 'under 70 tonnes'. The HST power car, rated at 2250hp, has a weight of 79 tonnes.

In previous rail traction applications gas turbines have been handicapped by their fuel consumption. Turbomeca claims the Jetrain would use 5% more fuel than an HST with its original Paxman Valenta diesel engine. Consumption would be further reduced by shutting down one or more turbines at speed.

However, the Valenta is a 30 year-old design and diesel engines have made substantial advances in fuel consumption. Paxman's latest VP185 has demonstrated savings of around 10% over the Valenta in HST service. Underfloor engines, such as the Cummins QSK19 in the 200 km/h Coradia and Voyager DMUs, are similarly frugal.

The Makila turbine is said to require only 1h of maintenance every 130000 km, and overhauls at intervals of up to 1·6million km.

Reader Enquiry Numbers

Bombardier Transportation 140

Turbomeca 141

CAPTION: Mediterr has developed a prototype servo-assisted shock-absorber with electronic controls. It is to be tested on an ETR500 high-speed trainset in service with Italian State Railways.

Mediterr Shock Absorbers, ItalyReader Enquiry Number 142