Kamil Hashmi is struggling to find his locomotive’s control system fault. He explains that in the laboratory he could listen to relays clicking but in a noisy environment he can’t diagnose faults this way. Kamil’s University of Birmingham team is taking part in the Institution of Mechanical Engineers (IMechE)’s Railway Challenge. His problem is one of many encountered by those taking part who have to make their technical solutions work on a real railway.
Small railway – big challenge
The real railway in question is the 10.25 inch gauge Stapleford miniature railway, near Melton Mowbray run by the Friends of the Stapleford Miniature Railway (FSMR). With an impressive collection of locomotives and two miles of track, it is one of the UK’s largest such railways. The IMechE considers it ideal for their Railway Challenge, one reason being that the railway is not normally open to the public although it has an open weekend on 24-26 August.
Held during the last weekend in June, this was the IMechE Railway Division’s second Railway Challenge (see issue 94, August 2012, for the first). It requires teams of engineering students, graduates or apprentices to design and manufacture a miniature railway locomotive to a technical specification.
Setting the standard
The teams were judged on their design (100 points), business case presentation (100) and performance challenges for traction (150), ride comfort (150) and energy storage (250) to regenerate traction power from energy stored during retardation. The last challenge has the highest weighting as it both demands an innovative approach and is a highly relevant research topic. On-board energy capture offers significant potential benefits to operators of self- powered mainline rail vehicles.
For maximum design flexibility and to encourage innovation, the technical specification is performance driven. Specific requirements include systems assurance, refuelling in 90 seconds, 95% recyclable materials and the preparation of detailed drawings and maintenance manuals.
Introducing the teams
This year’s entries were from the University of Huddersfield, Interfleet Technology, Manchester Metropolitan University and the University of Birmingham. Huddersfield was the only newcomer while the other three teams used locomotives first seen last year but which had since been subject to impressive levels of development.
The teams varied in size and experience. Interfleet, led by James Edwards, consisted of its intake of eleven first-year graduates and four second- year graduates from last year’s competition.
Birmingham, on the other hand, was led by Rob Ellis and made up of two MSc students and two PhD students, only one of whom had competed last year.
Manchester was represented by a team of six students, two of whom had taken part last year, led by Chris Adams. The Huddersfield team originally comprised eleven students whose contribution to the locomotive was part of their course. Five students actually took part in the challenge and were led by Siddiq Albusmait from Bahrain which, as he pointed out, is a country with no railways.
Hydrogen is the new diesel
Railway Division chairman, Chris Moss, was impressed by the range of technologies in the teams’ locomotives. For example, Manchester’s locomotive used a spring for energy storage. Birmingham’s used hydrogen fuel cells with a continuous output of 1.1kW feeding batteries of 4.3kWh capacity to provide traction power. This compares with a typical 4kW output of the generator sets in the other locomotives. Rob
Ellis demonstrated this to be a practical power source by using it to cook his team’s campsite dinner. He felt that “Hydrogen is to diesel what diesel was to steam”.
The need for control systems for both traction and energy recovery had been a challenge. Huddersfield used a programmable logic controller supplied by its sponsor, Rockwell Automation. Interfleet Technology and Birmingham had both replaced the previous control systems on their locomotives. Interfleet used a seamless four quadrant control system whilst Birmingham developed a low cost system using a Raspberry Pi, a credit-card-sized single-board computer developed for basic computer science teaching.
This year the competition was sponsored by the Enabling Innovation Team (EIT) and Technology Strategy Leadership Group (TSLG) whose role was described in the article ‘Inspiring Innovation’ (issue 90, April 2013). David Clarke, the EIT’s director, was impressed by the teams’ real innovations such as hydrogen fuel cells, super-capacitors for traction energy storage and mechanical regenerative braking, which have potential for the real railway.
David commented: “The Railway Challenge is a great way to promote innovation and provide young rail engineers with the opportunity to show what they can do as well as giving them the necessary skills to promote innovation.”
New this year
Rachel Pearson, the IMechE’s project manager for the challenge, explained how the competition has evolved from last year’s pilot scheme from which much has been learnt. One improvement was the use of IMechE and FSMR Controllers through whom all railway movements were made.
This year’s event was made more attractive to spectators by providing a refreshment area with a scoreboard next to the trials to which spectators travelled on a steam hauled spectator train. Around 50 spectators attended the event including potential entrants for next year.
Last year’s competition showed the rules and technical specification to be generally sound. The few changes included a maximum speed increase to 15kph and the energy challenge trial taking place on level track.
A testing time Saturday was the team testing day with each given two 45-minute time slots to test their locomotives against the three performance challenges. For most, this provided the first opportunity to run their locomotive over a distance on a railway with curves and points. It is fair to say that, for most, this day did not go smoothly. On one occasion the rescue train, hauled by FSMR’s Warship diesel locomotive, was used to propel a failed locomotive back to the station.
Problems experienced included: failed drive chains, loose electrical connections, electronics overheated by the adjacent generator set and a low drive chain causing a derailment (not such a problem on a 10.25 inch railway). It was significant that, as last year, Interfleet’s locomotive did not suffer from such teething problems. Prior to the competition their team had commissioned their modified locomotive on the Rudyard Lake miniature railway where they ironed out some minor problems.
This was also the day for scrutineering, which locomotives must pass to compete in the trials. Head scrutineer Tim Poole explains that this is done by confirming design calculations, physical inspection and tests when the locomotives are running including proving that the locomotive cannot exceed 15kph. As each of the six scrutineering categories (Indication, Brakes, Safety, Fuel, Calculations and Demo) are passed the locomotive collects a sticker. The full set shows the locomotive is fit to compete in the trials.
Business case presentations also took place on the Saturday. This required teams to consider themselves as representatives of a design consultancy producing a prototype locomotive for sale to a large corporation. This assessed each team’s ability to deliver a presentation to convince a group of executives of that ‘large corporation’ (the judges) that their design best met the customer’s demands and could be profitably manufactured and marketed.
The Stapleford Trials
Locomotives were assessed against the three performance challenges on the Sunday. The ride test used a vehicle body-mounted accelerometer as the locomotive ran around the railway’s half mile main loop and was assessed in accordance with EN 12299:2009.
Energy recovery was measured by the distance travelled using energy stored by braking from maximum speed. Traction ability was measured by the time for a measured distance up the railway’s maximum 1 in 80 gradient from a standing start. A judge rode on the train during each test to ensure rules compliance. For example, for the energy challenge, the judge had to ensure that the locomotive had no stored energy prior to braking.
After each challenge, results were displayed on the scoreboard. An initial surprise was Birmingham’s small locomotive with its 1kW fuel cell taking an early lead in the traction challenge, only to be narrowly beaten by Huddersfield. The University of Huddersfield also comfortably won the ride comfort challenge, proving the benefits of their use of VAMPIRE software (DeltaRail) to model vehicle dynamics.
Manchester’s mechanical energy storage won the energy challenge, covering twice the distance of its rivals who used electrical storage. Huddersfield could not take part in this trial as their impressive looking axle mounted energy storage system was not quite complete.
And the winner is ….
There was tension in the air as everyone waited for the judges to complete their deliberations as there was no obvious winner. In making his deliberations, chief judge Bill Reeve said that it had been an absolute pleasure to deal with the teams whose abilities greatly impressed him. That pleasure lasted up to the point when he had to give the scores, because not everyone could win and the scores were very close.
Giving the results in reverse order he considered that Birmingham was an extraordinarily creditable fourth. The judges were impressed by the way they had reduced costs with a design that used standard components. Third was Interfleet with a locomotive that Bill felt was the most practicable machine even if others had beaten it at specific challenges. Manchester’s second place was largely due to it having the best energy storage system.
Announcing Huddersfield as the winners Bill made it clear that this was not beginner’s luck. The judges were impressed by the quality of engineering from first principles and the clear way engineering designs had been presented.
The winner’s cup was then presented by Network Rail technical director Steve Yianni. Accepting the award, team leader Siddiq Albusmait said it made the team’s hard work over the past nine months all the more worthwhile and that he was particularly thrilled as the other teams had done so well. “Taking part in this competition has been fantastic – giving us first-hand experience of the entire process of developing a locomotive”.
Having observed the competition it would seem that successful teams need to:
- Test their locomotives before the challenge. There are around fifty 10.25 inch gauge railways in the UK which could potentially offer testing.
- Understand the limitations of standard components. A failed chain, for example, could undermine all the hard work done to develop an innovative feature.
- Effectively project manage their time. A component that is 99% complete is useless.
- Make a good business case presentation that includes engineering, reliability, cost and other benefits that would make the customer want to buy the locomotive.
With the possibility of single component failure preventing a locomotive’s participation in the challenge, The Rail Engineer hopes that these points may benefit future entrants.
The Railway Challenge is a great success. This was evident from the enthusiasm of everyone concerned and the smooth running of the event, in no small part thanks to the Stapleford Miniature Railway. Offering a small team the opportunity to design and build their own locomotive is a particularly effective way of developing young railway engineers which must ultimately benefit both the rail industry and their employers.
For the IMechE, the challenge is to grow the competition. This year the teams were largely provided by universities, with the exception of Interfleet for whom work on its locomotive is an integral part of its graduate training programme. The IMechE hopes that other rail companies will see the benefits of participating in this challenge next year. If so, expanding the competition brings its own challenges with operational constraints for FSMR and IMechE to overcome.
For future competitors, the Railway Challenge will no doubt continue to provide an opportunity to produce innovative locomotives with technologies that may eventually find use on standard gauge railways.