It is always a pleasure to report on the Institution of Mechanical Engineers’ Railway Challenge, as Rail Engineer has done since the first competition in 2012. Experiencing the enthusiasm, energy and ingenuity of the teams taking part, seeing the professionalism of the senior engineers from the Institution’s Railway Division who volunteer to run the event and the opportunity to experience the Stapleford Miniature Railway make this a thoroughly enjoyable weekend for all concerned.
The Railway Challenge requires teams of graduates, students or apprentices to design and build a 10¼ inch gauge miniature locomotive that must compete in various challenges, with marks also given for reliability. Before the locomotives can enter these challenges, they must pass static and dynamic scrutineering to confirm that they are built to specification and safe to run. Teams are also assessed on their design and innovation reports and how they present the business case for their locomotive.
This year’s challenge took place on 28, 29 and 30 June. It was run in accordance with its rules and a technical specification which is, as far as possible, performance-based. The intention is to encourage novel ideas – in past competitions these have included the use of springs for energy recovery and hydrogen fuel cells for traction, which was first seen in the UK at the Railway Challenge.
As always, the challenge took place on the 10¼ inch gauge Stapleford miniature railway, near Melton Mowbray, run by the Friends of the Stapleford Miniature Railway (FSMR). This has an impressive collection of locomotives and is one of the UK’s largest such railways. It is considered to be ideal for the Railway Challenge, especially as it is not normally open to the public.
Ringing the changes
Over the years, it has been interesting to see how the Challenge has developed, although some things, such as the enthusiasm of the teams, don’t change. Also, as the table of previous results shows, for the past few years only around 70 per cent of the locomotives present were able to undertake the dynamic tests. Ensuring all systems are operational on a recently built or modified locomotive is a significant challenge and it is not unusual for a team to spend most of the night repairing their locomotive. As will be explained, fried electronics were a significant problem this year.
What does change is that each year there are new challenges and variations to the rules and technical specification. This year saw a new auto-stop challenge, which required the locomotive to stop exactly 25 metres after passing a marker provided by the team. A recent rule change concerned refuelling. Prior to 2018 this rule stated that refuelling shall not comprise the replacement of energy storage assets (batteries) and should be done in 90 seconds. Since then, this rule has been changed to allow battery replacement within a refuelling time of 120 seconds.
In 2018, following this rule change, three of the ten competing locomotives were battery-powered. This year, with the same number competing, eight were powered by batteries.
Also new this year was a schools’ event, which Jelena Gacesa, operations manager of the IMechE’s education programmes, had initiated by inviting Leicestershire schools to an educational event during the competition. About a dozen pupils from Inglehurst Junior School in Leicester took up this invitation.
This involved a competition to build the tallest working model lighthouse, seeing the teams work on their locomotives, a ride on the railway and a quiz on what they had seen.
The quiz’s requirement to draw a picture of a railway carriage of the future brought some interesting responses. One of the teachers present, Debbie Walsh, felt that the event fitted well into the design and technology module in the school’s curriculum. Encouraging youngsters to consider an engineering career in this way is a worthwhile initiative and it is hoped that this will be expanded during next year’s Railway Challenge.
Introducing the teams
Of the 14 teams that entered the competition this year, only 10 were able to bring a locomotive to Stapleford. Of those unable to attend, Helwan University in Egypt, South Western Railway with CEMAST college and the University of Warwick had submitted design reports with the latter submiting an innovation paper.
This year saw two teams from the European continent, the joint team of FH Aachen University and Reuschling GmbH from Germany and Poznan University of Technology, whose journey from Poland to Stapleford had taken 21 hours. Also present was a large team from several Thai universities, including Suranaree University, who have started building the locomotive that they intend to enter in next year’s Challenge.
The UK universities entering were Brunel, Sheffield and Huddersfield and there were company teams from Network Rail, Ricardo Rail, SNC Lavalin and Transport for London (TfL). There was also a joint Bombardier / University of Derby team.
The new entrants this year were Network Rail (supported by the University of Birmingham) and Poznan. SNC Lavalin, formerly Interfleet, has entered all eight Challenges to date. Huddersfield and TfL were also veterans of the competition with respectively seven and six entries.
Brunel’s pneumatic powered entry bore a strong resemblance to a steam locomotive. Sheffield’s two-unit locomotive was also distinctive, with its clear cover and semi-circular body section. Ricardo had the look of a retro diesel locomotive whilst others had striking liveries. For example, TfL’s entry was painted to resemble the preserved 1923 Metropolitan Railway electric locomotive ‘Sarah Siddons’.
As previously mentioned, eight locomotives were powered by batteries which had the capacity to operate the locomotive for three hours without refuelling. The exceptions were Huddersfield and Brunel, whose machines were powered by 7kW petrol generator and 8kW petrol powered compressor respectively.
Although the norm was a battery-powered single-unit locomotive on two four-wheeled bogies, there were significant design variations in respect of auto stop arrangements, braking systems, electronic control, suspension and bogie design. Poznan had a particularly elegant bogie design, with the frame manufactured from an aluminium / polyethylene composite and carbon-fibre composite primary leaf springs.
A challenging plan
The Railway Challenge requires the teams to undertake presentation and track-based challenges. The four presentation challenges with their maximum scores were: design (150); business case (150); technical poster (150) and innovation (150). The design and innovation challenges are the only ones judged beforehand, based on submitted reports. The poster challenge is judged during the weekend, as is the business case challenge, based on the team’s presentation to the judges.
The seven track-based challenges were: energy storage (150); traction (150); ride comfort (150); noise (150); auto-stop (150); reliability (300) and maintenance (150).
Except for the maintenance challenge, these are all dynamic tests that require the locomotive to have passed scrutineering before it can run on the railway. This requires the collection of a set of seven coloured stickers, awarded when a scrutineer has confirmed the safety calculations, undertaken a physical inspection, seen the user guide, together with the required markings, as well as indications and evidence of reliability.
Once this has been done, dynamic scrutineering examines the required safety performance, primarily braking and speed control.
Undertaking these tests, allowing for test runs, a rescue locomotive and spectator trains, requires a detailed operational plan that is sufficiently flexible to accommodate inevitable changes during the weekend. Bridget Eickhoff of RSSB, as the IMechE’s operational controller, had the job of managing this plan to ensure the Challenge ran smoothly.
The plan was for most locomotives to be unloaded on the Thursday night, with the remainder unloaded on the Friday when all the static and dynamic scrutineering was undertaken, together with some of the maintenance challenges. On the Saturday the remaining maintenance challenges were completed and each team gave their business case presentation. They also had the opportunity to give their locomotive a 45-minute test run.
- All the dynamic track-based challenges were run on the Sunday, when the FSMR also ran steam-hauled trains for the dozens of spectators who witnessed the challenges from the Haven.
- Sunday’s operational plan required that, during each hour, a spectator train would run, two locomotives would undertake their dynamic challenges and a rescue locomotive would be available to assist either locomotive if required. The planned movement sequence during each hour was as follows:
- Spectator train leaves the station and proceeds around the loop to point G;
- Once the spectator train has passed the signal box, Challenge locomotive No 1 and its train leaves the station followed by the rescue locomotive. This locomotive does the auto stop challenge. It and the rescue locomotive move clear of the points at the Haven signal box;
- The spectator train departs for the station. locomotive No 1 does the ride comfort test and stops at point E followed by the rescue locomotive;
- When the spectator train arrives at the station, locomotive No 2 departs, it undertakes the auto stop challenge and moves clear of the points at the Haven signal box;
- Locomotive No 1 completes the energy storage challenge, whilst locomotive No 2 does the ride comfort challenge and stops at point E;
- Locomotive No 1 does traction and noise tests and returns to the station. The rescue locomotive follows it to just before point H;
- Once locomotive No 1 is at the station, the rescue locomotive stays ahead of locomotive No 2 whilst it completes its energy storage, traction and noise challenges. The rescue locomotive and locomotive No 2 then return to the station.
In this way, with the railway operating at its capacity, two locomotives an hour were put through their challenges. Thus, assuming an intensive seven-hour operational day, 14 is the maximum number of locomotives that can be put through the dynamic track-based challenges. However, there are plans for alterations to the railway that will significantly increase this number.
On the Friday, the maintenance challenge saw the start of the contest as teams demonstrated how fast they can remove and replace a powered wheelset. The time each team took to do this varied from 2½ to 27 minutes and was largely a reflection of the way their locomotives were designed to meet this challenge.
To ensure that this challenge was conducted in a safe manner, it was done in accordance with an approved method statement and undertaken in several stages. After each stage, the stopwatch was paused until the judges confirmed that it was safe to continue.
As well as the maintenance challenge and scrutineering, Friday and Saturday also saw much work done on the locomotives to resolve various problems. Some of these reflected the lack of testing, as some teams had only run their locomotives on short tracks by the workshop. Hence, not all locomotives had been run at full power for long periods or experienced the harsh vibration environment and impact loads from continuous running.
The most significant problem was fried electronics, with some teams suffering burnt out motor controllers. This was an issue for Poznan and Network Rail, whose locomotives operated at reduced power as a result. Part of the information that the Institution provides to the teams is a useful ‘technical tips’ presentation. This includes a slide showing that traction components need to be significantly over-rated as traction motors have a spikey current profile.
Nevertheless, despite these problems on the Friday and Saturday, all the teams, except for Brunel, were able to take their locomotives for a test run around the railway’s 2.6-kilometre long circuit, although the Poznan locomotive had to be pushed back by the FSMR’s rescue locomotive.
Unfortunately, Brunel was not able to overcome the problems associated with the unique design of its locomotive.
Thus, it looked as though Sunday would see the previous maximum of seven locomotives doing the dynamic challenges being exceeded. However, this was not to be as, Brunel could still not run, SNC Lavalin had a burnt-out motor controller and, unfortunately, as Poznan’s locomotive left the station, it was damaged after it hit an obstruction and was unable to proceed further.
The first hour of the day saw Ricardo and Aachen’s locomotives running exactly to the operational plan. Thereafter, due to locomotive availability, only Bombardier/Derby and TfL shared an hourly slot and Sheffield, Huddersfield and Network Rail ran alone during their challenges.
Some of the locomotives were unable to undertake all the tests. For example, when starting, Huddersfield’s locomotive suffered from a jerky traction control which prevented it starting on the gradient for the traction and noise challenge. With burnt out controllers, the underpowered Network Rail locomotive could only do the ride comfort challenge and required the FSMR rescue locomotive to push it up the gradient back to the station.
All this was observed by dozens of spectators from their vantage point at the Haven, who were kept informed by Rail Engineer’s own Nigel Wordsworth and his megaphone. The track challenge results were also displayed on a scoreboard.
The spectators were well placed to see how the locomotives tackled the new auto stop challenge, in which a track-side marker of the team’s own design had to be used to command the locomotive, travelling at a speed of not less than 10km/h, to stop at point B, 25 metres beyond the marker. The wide variety of markers used included lengths of rail between the track, an infra-red control from inside a TV remote, ultrasonic detection, a traffic cone and caravan reflector. Unfortunately, of the six locomotives entering this challenge, only two stopped within five metres of point B and so were the only ones to score points.
And the winners were
There was tension in the air as everyone waited for the prize-giving. After a short delay, the appearance of chief judge Bill Reeve signalled that the judges’ deliberations were complete. Bill advised that, in the view of the judges, this had been the best Railway Challenge yet, with some real innovation in design, and everywhere there had been real enthusiasm and commitment from the teams.
Before declaring the overall winner, awards were made for the individual challenges. In addition to the track challenges shown in the table, the winners of the presentation challenges were:
- Design – jointly won by SNC Lavalin and TfL;
- Business Case – TfL;
- Poster competition – SNC Lavalin;
- Innovation – University of Warwick.
Although not present, Warwick had won its award for an innovation report entitled “a study of efficiency improvement for an electrical regenerative braking system.”
The other challenge award was for reliability, which was jointly given to Sheffield and Bombardier/Derby which had each achieved a not-quite-perfect 290 points out of 300.
In addition, this year the judges gave a discretionary award for something that particularly impressed but was not reflected in the challenges. This special award was given to Poznan for innovation and elegance in mechanical design in respect of the composite bogie frame and leaf spring bogie.
Then it was time to announce the top three teams. In third place was Ricardo with 1099 points, narrowly beaten by TfL’s 1100 points. The overall winner was Aachen with an impressive 1389 points. Team captain Robin Muhlmeyer commented “We are participating now for the third time in the Railway Challenge and have continued to make progress each year. This time it was enough for us to take the trophy back with us. It’s always an incredible pleasure to be here at the Stapleford Miniature Railway.”
It was then time to thank those who had made the challenge possible, including the Institution’s staff, the sponsors (Angel Trains, Beacon Rail Leasing, RSSB and the Young Rail Professionals Group), support from Network Rail and, last but not least, the unstinting support from FSMR personnel who ran the railway during the challenge. FSMR is also actively supporting planned enhancements to its railway that will enable the challenge to accommodate up to thirty locomotives in future.
As the Railway Challenge goes from strength to strength each year, this expansion plan will no doubt be required as more organisations wish to enter so that they and their young engineers can benefit from it. As Bill Reeve noted; “When I come to this event, I see enthusiastic teams learning, in a short period, a huge amount about the realities of engineering projects. I also see real innovation in engineering design tested here in a low risk environment.”
Put another way, the Challenge is an excellent way to train and develop young engineers.