With its focus on innovation, there’s always something new at the Institution of Mechanical Engineers’ (IMechE) Railway Challenge, especially as the competition had a record twelve entries this year. The challenge was held over the first weekend in July and was managed by the Institution’s Railway Division, with around twenty volunteers running the event. Under the guidance of a steering group led by Professor Simon Iwnicki, the Division produces the competition’s rules and a performance-based locomotive specification. This is changed each year to encourage modification of previously entered locomotives.

The IMechE provides a small number of staff to administer the event, arrange the facilities required and seek sponsorship. This activity is led by Sandra Balthazaar, the Institution’s education manager, who is charged with inspiring the next generation of engineers, including through outreach activities in universities. This year, the competition was sponsored by the Railway Industry Association, RSSB and Wabtec.

Regular readers may recall that Rail Engineer has reported on every Railway Challenge since the first competition in 2012. Each year, the competition is held on the three-kilometre track on the Gretton family estate near Melton Mowbray, operated by the Friends of the Stapleford Miniature Railway (FSMR).

It is essentially a miniature version of the Rainhill trials, in which apprentices, students and graduates are required to design and build 10¼” gauge locomotives to the competition’s specification. These are then subject to track-based challenges to test energy storage, traction, ride comfort, noise, maintainability and reliability. In addition, there were presentation challenges for design, business case and innovation. There is a maximum of 150 points for each challenge, except for the energy challenge which scores up to 300 points.

Brunel’s locomotive

This year Brunel University provided something that was both new and unexpected: a piston-driven locomotive (above) with coupling and connecting rods driving four axles. The pistons were driven by compressed air at eight bar, admitted by computer-controlled solenoid valves. For a high starting torque, the design was for an eighty per cent cutoff (the point in the piston stroke at which the inlet valve is closed) on starting, reducing to forty per cent at maximum speed.

For the energy storage challenge, the pistons store compressed air in an auxiliary tank which is then used to power the locomotive away from a standing start.

To allow the locomotive to get around the sharp curves at Stapleford, the locomotive axles have a 20mm lateral float, achieved by keying them into both the axle bearings inner races and their cranks, which would otherwise have restricted the axle float.

Also new this year

After a ten-hour journey from Germany, a team from the department of mechanical engineering and mechatronics (or Fachbereich Maschinenbau und Mechatronik) of FH Aachen University of Applied Sciences gave the competition its first non-UK entry. The FH Aachen locomotive was to have been hydrogen powered. However, for various reasons, it was not possible to use the locomotive’s hydrogen fuel cell, leaving only the batteries to power the loco.

University of Birmingham and AEGIS engineering systems locomotive under test.

A battery health monitoring system, that counts coulombs (the unit for electrical charge, equivalent to one ampere-second) in and out, was considered by the SNC-Lavalin team to be its first UK railway use. Another first for the challenge was the array of five 50-watt solar panels fitted to the entry from the University of Southampton and Siemens.

The locomotive from the University of Birmingham and AEGIS Engineering Systems was also powered by a hydrogen fuel cell. However, this was not a new development as Birmingham entered a hydrogen-powered locomotive for the inaugural Railway Challenge in 2012. Their innovation this year was to use a silicon carbide inverter as one of their two power converters. This offers high efficiencies, and so requires less cooling, and also produces less electrical noise, reducing the requirement for smoothing capacitors and offering significant weight saving on a full-size locomotive.

The teams

The challenge rules state that those eligible to enter must be either a student on a university engineering course, an engineering graduate within two years of graduation, a member of a monitored professional development scheme for less than two years or an apprentice.

The teams are generally a mix of students in their final two years, whose work on the challenge is part of their degree course, or rail company graduates for whom the challenge is part of their training programme. Three teams were collaborations between academia and industry: University of Southampton with Siemens; Bombardier with the University of Derby and the University of Birmingham and AEGIS Engineering Systems.

At the University of Sheffield, the team comes from the Railway Challenge at Sheffield (RCAS), an extracurricular student-led club within the mechanical engineering department supported by the university. As such, the team is made up of all university years and students get no course credit for the work on their locomotive. As the five final-year students in the Sheffield team now have positions within the rail industry, such enthusiasm brings its own rewards.

From the eleven teams which made it to Stapleford, there were about a hundred competitors in total, with women making up a fifth of those taking part.

A challenging operation

The Stapleford Miniature Railway has a station with various sidings and a turnaround triangle. From the station, an 800-metre single line runs down a 1 in 80 gradient to a 1.2km balloon loop. This year’s competition plan required each of the entries to run around this loop three times, with the FSMR also running steam-hauled spectator trains on the Sunday.

This was a challenge that needed a detailed operational plan, with the flexibility to deal with locomotive failures. Bridget Eickhoff of RSSB, as the IMechE’s operational controller, had the job of ensuring the challenge ran smoothly.

Southampton and Siemens undergo their maintenance challenge as Simon Iwnicki looks on from behind.

After unloading, the plan for the first day, Friday, was to complete scrutineering to confirm that each locomotive had been built to the specification and that it could safely compete. This consisted of a series of static and dynamic tests to confirm, for example, whether the locomotive had the required braking performance. To complete scrutineering, a locomotive had to collect the required set of seven stickers to demonstrate satisfactory compliance with all the tests.

Half the teams also attempted their maintainability challenge on the Friday. This was a timed test that required them to remove and replace a wheelset, performed under the strict eye of the judges who paused the test at appropriate times to ensure it was done safely.

Saturday and Sunday

On the Saturday, the remaining maintenance challenges were completed and teams were given an opportunity, one at a time, to test their locomotives on the railway. They were closely followed by the rescue locomotive, the FSMR’s model Warship diesel-hydraulic locomotive powered by a 1600cc Ford Cortina engine, which was ready to effect a speedy recovery if needed.

Saturday was also the day for the business case challenge. Teams had to present themselves to a panel of judges to make the case as to why a hypothetical customer should buy their creation. Nerve-wracking stuff!

Sunday was the day for spectators to witness the track-based challenges. The operational plan required the first spectator train to leave at 09:30, closely followed by team one’s train and the rescue locomotive. Once these trains were in the balloon loop, the spectator train returned to the station, allowing team two’s train to depart for the test area.

In this way, the plan was to run a spectator train and two test trains every hour. In the event, only eight locomotives were able to enter the track-based challenges and it took 4½ hours for them to undertake their tests. Only one required assistance from the rescue locomotive.

Non-runners and casualties

Every year, just getting locomotives to the line is a challenge in itself. University students don’t even meet up until October, so getting a locomotive (or upgrades to a previous one) designed, built and tested by the end of June is a real struggle. Every year, one or more teams are still finishing off their entries in the sidings at Stapleford, that’s if they turned up at all!

This year was no exception. Of the twelve entries, Manchester Metropolitan University was unable to attend and Alstom had arrived at Stapleford with a non-operational locomotive. It had blown a power inverter and a replacement could not be sourced in time. Nevertheless, the team acquitted themselves well in the maintenance and business challenges.

The joint Bombardier and University of Derby team also had problems with the power electronics on their locomotive and, despite much effort, could not get it operational for the track challenges.

Brunel University’s piston driven locomotive was, according to chief judge Bill Reeve “unquestionably the most popular locomotive that has ever turned up”. Its test run on the Saturday certainly attracted interest although a problem with its solenoid control prevented it exceeding walking pace, so it was also unable to undertake the track challenges.

Of the remaining eight locomotives that did, there were two casualties. The ride comfort challenge is measured over one kilometre and must be completed in less than six minutes. Due to fuel supply problems, the Transport for London (TfL) locomotive was unable to achieve this time. However, once this issue had been resolved, it was able to undertake the remaining track challenges.

FH Aachen’s locomotive also failed during the ride comfort challenge. Its auto-tensioned toothed belt drive looked to be more reliable than the chain drives that had been a significant problem during previous competitions. Unfortunately, the belt itself had parted. Although Reeve expressed his admiration for the impressive manner that the team quickly got their locomotive working with one powered bogie, this was not enough and the FMSR rescue locomotive had to assist FH Aachen back to the station.

A president with no regrets

Carolyn Griffiths is both a railwaywoman and the IMechE’s new president. At the prize ceremony, she considered herself to be “living proof that railway engineering is really very interesting”. Although she hadn’t planned to be a railway engineer, it was something she had done all her working life. As she told everyone: “I haven’t left and I’ve no regrets.”

In making this point, she was echoing Bill Reeve’s comment to the competitors that the “whole idea of this event is to encourage you to see railway engineering as a career”. From the sheer effort and enthusiasm displayed by the teams, he was hopeful that the challenge would succeed in this aim.

The first prizes were for the sponsored challenges, starting with the RSSB’s innovation challenge. Bridget Eickhoff presented the certificate for this challenge to the University of Birmingham/AEGIS team.

The design challenge was sponsored by Wabtec. Brush Traction’s engineering director, Chris Myatt, found himself presenting certificates to three teams rather than one. As head judge Bill Reeve explained, the judges considered that the entries by Huddersfield, SNC-Lavalin and TfL were all exceptionally good submissions with nothing to choose between them.

The Railway Industry Association (RIA) sponsored the business case award. Its technical director, David Clarke was pleased for RIA to sponsor this as it reflected all the things the association likes: encouraging people into the rail industry, skills and innovation. Proving that it’s possible to win something without a working locomotive, the award went to Alstom for a business case that was described as “outstanding”.

Track challenges

In awarding the track challenges, judge Malcolm Dobell noted that Birmingham and Southampton/Siemens had respectively won the energy storage and traction challenges by a large margin. He advised that the maintainability challenge had been won by Sheffield and the ride comfort challenge by SNC-Lavalin, which also won the noise challenge. However, following a judges’ review, it was realised that this should have been a joint award with Warwick.

Reeve announced that the judges wished to give two special awards to teams that had particularly impressed. These went to FH Aachen, for its initiative in getting to Stapleford from Germany, and the Brunel for its popular and novel locomotive.

Stressing that the judges were open to all forms of traction, Reeve commented that the judges couldn’t help but notice that, when adjusted for load, the outstanding traction performance was FSMR’s 2-8-4 steam locomotive. Hence, it was felt that a special load-adjusted traction award should be presented.

Dobell then announced the results in reverse order, finally revealing that SNC-Lavalin had won overall. However, it had been a close-fought competition. Out of a maximum of 1,500 points, the scores for the top three teams were: Huddersfield (889); Birmingham/AEGIS (1041) and SNC Lavalin (1087). These teams had also jointly won the reliability award.

Everyone a winner

IMechE president Carolyn Griffiths acknowledged that whilst there had “clearly been some heart-rending moments, all the teams had been successful”. She felt that designing and building such prototype locomotives in a short lead time was a “phenomenal achievement”. She was sure that the practical experience gained by the teams, as well as learning about business economics, project planning and time management, would prove invaluable.

In this respect, everyone was a winner. So was the railway industry as a whole, since the challenge must help attract young engineers to the railway industry.

The Railway Challenge can only take place with the support of sponsorship from RIA, RSSB and Wabtec, the Railway Division’s volunteers, support from the Gretton family and FSMR members whose enthusiastic help is also invaluable.

But what of its future? Since 2012, the number of locomotives attempting the track challenges have been three, four, four, four, five and eight. This indicates that increased numbers can be expected next year.

Subject to confirmation, the 2018 Railway Challenge is expected to be held on Saturday 30 June and Sunday 1 July with scrutineering on Friday 29 June. The IMechE will open the entry list on Monday 23 October and the first 16 entries will be accepted.

Thus it seems likely that “biggest challenge yet” will apply to this competition for some years to come.

Written by David Shirres


Organisations interested in entering the 2018 Railway Challenge should contact the IMechE’s Sandra Balthazar at S_Balthazaar@IMechE.org.