Traction test: The University of Birmingham's 2013 locomotive is put through its paces
This month will see the grand final of the IMechE Railway Challenge take place in Leicestershire. Five teams of engineering university students and apprentices from all around the UK will go head-to-head to test the working miniature locomotives that they have spent the past nine months designing and building.
Now in its third year, the challenge was set up in a bid to replicate the successes of Formula Student, the educational motorsport competition that attracts entrants from around the world. In Formula Student, teams build single-seat racing cars to be tested against other contestants’ designs at Silverstone.
The contest has become a brilliant way of attracting students to automotive engineering courses and on to careers in motorsport.
Professor Simon Iwnicki felt that a similar competition for railway engineering was sorely needed after witnessing first-hand the difficulties of recruiting graduates into the industry. Iwnicki, professor of railway engineering at Huddersfield University, says: “Even the students that come through on engineering courses, mechanical, electrical and so on, they haven’t really thought about railways. They’re all focused on automotive or aerospace engineering instead. Neither they nor their teachers seem to realise that there are lots of very interesting, rewarding careers in this field.”
So the aim of the Railway Challenge is to overhaul the industry’s image among students and provide the next generation of engineers poised to enter the profession with valuable practical skills. Iwnicki, who is now the chairman of the contest’s rules committee, says: “The best thing about it is that the students work as they will do in real engineering life – in a team. They need to build up expertise in different areas. They need to learn about hydraulics, pneumatics, electronics, traction, structural design and railway engineering. They also need to manage their time, work together, share out tasks and learn how to communicate effectively.”
Over the past nine months the teams have been well and truly put through their paces, but for the locomotives the challenges are yet to come. The final competition will be held during the last weekend of June at the miniature railway at Stapleford Park, near Melton Mowbray. With nearly two miles of track, it is one of the longest railways of its kind in the country. For the team members, the weekend will be the culmination of all their hard work.
Their small-scale locomotives and their engineering prowess will be put to the test in a series of track-based and presentation challenges. Only one team will be crowned the victor but all those involved will leave with ‘real world’ skills and, hopefully, a passion for railway engineering that they may otherwise have never discovered.
The Railway Challenge mirrors a real-life tendering process. Teams of students and apprentices from industry are asked to imagine they are working for a design consultancy producing a locomotive for a large corporation. In just nine months they conceive, cost, design, source materials and build a 10¼-inch-gauge prototype to be tested against competing vehicles. Teams also put together a written business case for their locomotive, as well as presenting their ideas to a panel of expert judges. The first day of the competition opens with a ‘scrutineering’ test, where the vehicles are run through a series of safety checks and teams are given the chance to fix any minor problems that are discovered. Locomotives then take to the tracks one at a time, to be judged and scored on four challenges.
This year’s entrants are from the University of Huddersfield, Interfleet Technology, the University of Birmingham, Transport for London (TfL) and the University of Sheffield. The last two are newcomers to the competition. The other teams have made modifications to locomotives used in last year’s challenge. Teams are permitted to re-enter designs owing to the high cost of creating a miniature locomotive from scratch, which can average £10,000.
The teams vary in size and experience, averaging 10 members and ranging from first-year to PhD students. What is consistent across all the entries is the high calibre of the designs and the students’ willingness to experiment with innovative technology.
Future engineers: Half of this year's Birmingham team with a third of their locomotive
Such an innovation can be found on Birmingham’s locomotive, which was entered in last year’s competition. It features a 1.1kW hydrogen fuel cell that feeds batteries of 4.3kWh capacity to provide tractive power. This inventive solution impressed the judges last year but failed to win. With the hydrogen fuel cell costing £20,000 initially, the new team made the decision to spend an extra few thousand pounds to make improvements to the original design.
Team leader Rob Ellis says: “A lot more mechanical engineering has gone into our design this year. We’re sticking with the hydrogen power but, rather than it just being a really expensive fuel cell surrounded by quite a cheap-looking train, we’re hopefully making a nice-looking train as well.” The mechanical engineering has come in the form of replacing the high-tech Raspberry Pi control system with a simple joystick. Ellis explains: “It’s a bit more traditional – there’s not any kind of complex wireless system that we had before. It’s a lot more analogue but it’s a lot more robust.” Following a poor performance in last year’s ride comfort challenge, they have also redesigned the suspension.
Interfleet, an international rail technology consultancy, entered the same locomotive design in the last two challenges and were crowned the winners of the 2012 competition, but missed out on the 2013 title to Huddersfield University. To keep up with this year’s rival entries, the new Interfleet team have been working hard to modify their locomotive, focusing on acceleration, ride comfort and noise reduction.
Interfleet team leader Emma Taylor says: “We’ve replaced the motors, which are powered by a petrol generator, with larger, more powerful ones to reach the top speed of 15km/h faster. It has changed the structure of the loco quite a lot. We’ve had to be careful as we’re now quite close to the size limit.” Hoping to edge out the competition, they have also added four batteries that will send an additional boost of energy into the motor controller.
New entrants TfL are hoping to set themselves apart from their competitors with the use of what they consider to be some exceptional features. These include air suspension to see them through the comfort challenge and a hydro-pneumatic regeneration system that team leader Luke Foy hopes will bring something completely new to the competition.
Foy explains that the hydro-pneumatic system, designed for the energy storage challenge, will use the movement generated by the braking locomotive to pump oil from a hydraulic pump into an accumulator. Compressed air will force the oil through a hydraulic motor to propel the loco forwards.
Foy says the team are confident their locomotive will perform well in three out of four of the challenges. But he is concerned about the prospects of making it through the noise challenge because of the loud petrol generators on board.
Foy says that the process of building the vehicle from scratch has been a real eye-opener and admits that the team may have originally underestimated the scale of the task. “This is our first year in the competition so we have no lessons passed on from previous years’ teams or any basis to go on. We truly were thrown in at the deep end.”
But the TfL team have learned vital lessons that they will take with them into industry, in particular, Foy says, the importance of meticulous planning at the design stage. “We believed our design was complete and so started construction but there were small unforeseen amendments that had to be made,” he says.
“A full design review was undertaken to ensure it did not happen again but it was a massive challenge that ate into our limited construction time.”
For the Birmingham team, Ellis says that their restricted budget meant that they experienced problems with procurement, with a great deal of time spent searching for competitive quotes. Long lead times were also an issue, he says, adding: “It’s very difficult when we’ve got two or three months to build a locomotive and two or three months for a part to be delivered.
“You realise the time it would take you to carry out an industry-level project, and why it takes 25 years to build a railway.”
In providing its young entrants with a real insight into all the stages of an engineering project, the Railway Challenge is helping to show them the kind of exciting and varied careers available in the industry. And with success stories of previous contestants emerging, it appears that the goal of inspiring the next generation of railway engineers is right on track.
One such success story is that of Kamil Hashmi, a member of last year’s Birmingham team. Ellis says: “He started out involved in the challenge as part of his final-year project but then it turned into a bit of a labour of love. It became a case of ‘look what I can do, I can engineer a locomotive and here it is!’.
“Kamil was offered a role at Interfleet on the competition day, and he’s been working there for a year now on a graduate placement.”
Smooth journey: The Interfleet team rides the rails at last year's competition weekend
Points mean prizes
The energy storage challenge (300 points) aims to assess how well the locomotive can recover, store and reuse kinetic energy from braking. It offers the highest number of points of all the challenges as it demands a creative approach and is a highly relevant research topic.
The teams must run their vehicle pulling a coach carrying a judge as a passenger for a distance of 135m. They must get as close as possible to the full line speed of 15km/h. The judge will then signal for them to cut the power.
Over a stopping distance of 5m, the locomotive will store the brake energy as it slows to a halt. The stored energy from the process has to restart the loco back into motion with the main motor switched off. The maximum deceleration rate at any time throughout the challenge is 1.3m/s².
The ride comfort challenge (150 points) is designed to test the suspension of the locomotive and asks the teams to complete a 1.2km circuit in less than eight minutes. The vehicle will pull a coach carrying a passenger who will judge the quality of the ride. Triaxial accelerometers are mounted to specific points on the body structure to record vibration data. The devices measure the motion of the train in three different directions (up and down, forwards and backwards, and side to side). The higher the mean values the more points the teams will lose.
The traction challenge (150 points) tests the ability of the locomotive to tow a vehicle from a standing start. Accelerating as quickly as possible, the loco that pulls the load the furthest in the fastest time will be awarded the maximum points.
This test will be run in combination with the noise challenge, a new category for this year that reflects the need in the industry to cut noise pollution. The locomotive must generate as little noise as possible at top speed. Sound is measured by microphones at the sides of the track.
The competition weekend will be held on 28-29 June. It is free for spectators to attend on both days. To reserve tickets, email Rachel Pearson at r_pearson@imeche.org