On the right track01 February 2006

Rail is said to be favoured by European governments as an alternative to road transport because of its environmental friendliness compared to people driving their own cars. With oil supplies likely to begin to fall at a time when world demand is increasing, and our roads becoming ever more clogged up, the use of rail is likely to grow.

In terms of risk to passengers, fortunately, trains are pretty safe. For example, using an established measure (see box below), in 1999 the level of deaths on rail was significantly below that of car transport, and this is despite 1999 being the year of the Ladbroke Grove crash in which 31 people died (and over 400 were injured). In 2003, there were no fatalities or serious injuries to rail passengers at all. However, it is always possible to do better, and it should still be feasible to achieve the same standards of safety, reliability and punctuality as they do in, for example Germany or the Netherlands.

Reducing risk and improving reliability in the rail industries may be achieved by much the same ways as in other industries. Information technology can be used to improve traceability of components and monitor maintenance work. Machine to machine communications can warn of developing problems before they become serious, and modelling can improve quality of design, especially where it concerns interactions between railway vehicles and rails.

As regards the trains, as opposed to the rails, much can be achieved with best possible quality in both design and manufacture. Only too often, UK commuters are made to wait on station platforms listening to explanations about technical breakdowns that frequently seem to be of an electrical or electronic nature. When this happens on new trains, the situation can seem farcical: an example of which was being stranded in a brand new Electrostar south of London's Victoria Station and hearing the driver announce that he was about to have to turn everything off in order to "re-boot the train."

One electronics company renowned for its reliability and quality is Siemens - and we recently visited the plant in Nuremberg, Germany, which makes motors and drives for trains.

The plant makes 2,500 traction motors and 800 to 1,000 inverters every year; customer returns are "very seldom". The traction, and indeed all the large motors made there, are still essentially hand crafted ? a picture we have from the 1950s showing windings being hand pressed into stator slots with wooden tools exactly represents the technique being applied today. The company has now automated the manufacture of the windings themselves and does so in semi-clean room conditions to avoid the possibility of contamination that might lead to short circuits. Insulation is still added by hand. Gearboxes are bought in from manufacturers noted for their reliability, including Voith, while the bearings come from SKF. All the motors are balanced with weights, high voltage and short circuit tested, and motors and attached gearboxes are again tested for voltage response and smooth running before they leave the factory.

But the real secret of achieving quality lies in the bar codes on all components, which are scanned at each manufacturing stage, and the SAP system that ensures 100% traceability of all components and operations. An example was an under-floor inverter being assembled by a technician; he carefully followed instructions from a laptop computer, and logged everything he did. If anything is found to be wrong, it is not hard to locate exactly where this happened and who was responsible. We were told by one of the managers: "We do not make quality: we just verify what we supply to our customers."

This verification goes as far as Siemens creating full-sized wooden mock-ups of its trains, with the drive systems and all cables placed at the same distances from the electrics as on the real version. This helps avoid EMC problems, such as that which may have led to the train computer system failing near Victoria Station.

Searching for more reliability, the R&D people at Siemens are also bringing out a new powered bogie for light rail that has no gearbox. The Intra bogie has rare earth permanent magnets mounted directly on the axles. Drive losses are reduced significantly, the arrangement has lower mass and there are only two bearings on each axle.

Improvements in design also reduce risk and improve reliability, as well as bringing other benefits. Although fire is mercifully an extremely rare event in modern rail accidents, GE Plastics has just announced a new grade of Rail-Lite thermoplastic composite from Azdel made with GE's Ultem, which is a polyetherimide (PEI) resin.

The material is being supplied as part of replacements for acoustic ceiling panels in the cabs of GE Genesis passenger locomotives for Metro-North railroad, which operates trains running into New York from Northern suburbs. The composite
uses long glass fibres and enables the manufacture of components with half the specific weight of alternative materials used in interiors. It quickly chars on exposure to flame and emits very low levels of smoke and toxicity. It meets the requirements of US FRA 49 CFR Part 238 flammability and smoke emission standards for railway passenger carriages and locomotives cabs, as well as Germany's DIN5510, Part 2 S4/SR2/ST2 rating. The panels are produced by American Acoustical Products, which calls them Hushliner panels. They have a proprietary five-layer construction that includes a perforated 'GTfilm' decorative laminate from Schneller, the Rail-Lite composite and various adhesives.

Other potential applications for Rail-Lite include: window masks, ceiling and side ceiling panels, Wainscott panels, seat backs, arm rests, tray tables, luggage racks, partitions and other interior trim components. It is considered to be a potential replacement for PVC, polyester, vinyl ester, phenolic FRPs or GRPs, high-pressure laminates and aluminium-based materials used in train interiors.

Other notable developments include the intriguing large, yellow canisters sitting on track beds, often associated with trackside boxes powered by solar panels and small wind turbines.

These units are supplied by Qhi-Rail, and perform the extremely useful function of applying grease to the insides of the rails on bends. Correct functioning has, until now, required manual inspection, which in the rail industry usually means a visit by teams of four men in yellow visibility jackets in what can sometimes be very remote locations.

Recently, the company has introduced a small box of electronics that allows such units to communicate automatically with central control locations, using the wireless Vodafone network. Information such as grease reservoir status, correct or incorrect functioning of the grease pump and number of trains that have gone past can all be communicated by what the company has designated AB Micro MT101 M2M (Machine to Machine) telemetry units. Units supplied to Network Rail are expected to save some £4m per year, as well as improve reliability and reduce the risk of possible accidents.

Also on the subject of track comes the problem of how trains damage them and why they occasionally fall off. The problem goes back to the very earliest days of railway technology when George Stephenson switched from cast iron to more expensive wrought iron rails for the Stockton and Darlington Railway to reduce the risk of rail breakages. Engineers have been studying the problems caused by interactions between train wheels and track ever since. This work continues, assisted by the computational capabilities of modern computers and software, in an age when train speeds continue to be pushed higher and while margins continue to be squeezed.

At a conference in Munich organised by MSC Software, Ilse Vermeij of NedTrain Consulting gave a presentation about studies of interactions between small light rail wheels and the 1:9 English Switch. At the present time, Dutch trains and trams with wheels less than 760mm are not allowed to run on sections of track with such 'English' points in case they become derailed. What was wanted was some computer modelling to establish whether modern, lightweight rail vehicles with small, flexible wheels to improve ride, can drive through English Switches without risk of derailment. The modelling problem was, like all real world systems, complicated. MSC Adams/Rail does include an English Switch modelling possibility but NedTrain found it to be inadequate, so they improved it, generating a 3D CAD model and taking cross sections every 20mm and putting them back into the model. Among other things, they wanted to include the effects of wear, which changes the groove width within the points. They then validated the model by correlating computer-simulated measurements with measurements made with real trains running through real points; they have come to the conclusion that small wheels, even those only 550mm in diameter, should not cause any problem for the modelled light rail vehicles. Also, speed has no influence worth mentioning, but independently rotating wheels are considered unfavourable. Their aim is to come up with a software tool that will predict whether a particular rail vehicle and bogie design is compatible with the English Switch points it might encounter, or if not, to determine if it can be modified, without having to resort to trial and error experiments.

This was followed by a presentation by Roman Sobolev, an engineer from the Railcar Building Company of Mordovia, VKM (Mordovia is a Republic within the Russian Federation) about how to design railtrack-friendly bogies. In order not to damage rails, as well as give a better ride to cargo, the suspension systems are crucial. At the same time, weight and cost have to be minimised, and the suspension system has to be capable of continuing to function at -60°C. It appears that the modelling problem was even more complicated than that, involving the trams and the English Switch. Sobolev used MSC.Nastran, MSC.Dytran, MSC.Marc, MSC.Adams, MSC.Adams/Flex and MSC.Adams/Rail software. The result is an ability to incorporate hydrosprings in a freight car bogie. Weight carrying abilities increased to 27t, and speeds rose to 140km/h at loads of up to 20t without damaging track. Design cycle times are now down to only two months.

The bottom line result is an increase in sales from 6,000 railcars per year in 2004 to 7,320 in 2005, despite being in an increasingly competitive marketplace.

SOE

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