2nd December, 2016

SEM2016 Day 5: The other side of the mountain

After 3 days of inspection and practice, Friday was the first day of competition. Here’s a quick refresher on how the competition works. Every team has 4 opportunities to complete a scoring run, consisting of about 18 km in 8 laps. To be considered valid, the run must be completed in under 43 minutes, which works out to an average speed of about 25 km/h. There are separate prizes for the prototype class (lean, minimal machines designed for all-out efficiency) and the urban concept class (which are more like practical cars, requiring an upright seat, four wheels and other luxuries). Cars are further classified by energy source: battery-electric, hydrogen fuel cell, petrol, Diesel, ethanol and natural gas. The winner in each class is the car that uses the least amount of energy for the course. Energy use is measured by the Shell technical team. The Geec is a battery-electric prototype, so we carry a standard-issue device that measures voltage and current, and works out the energy transfer from our battery. It’s zeroed at the start of every run and checked at the end to work out the energy score. In fuel-burning classes, they simply measure the volume of fuel used. It’s a race where speed doesn’t matter, as long as you get back under 43 minutes.

Another windy showery day in London made the race schedule volatile. Urban concept cars can race in the rain, but prototypes don’t, because they don’t have windscreen wipers and they mostly have slick tyres. As we have noted with pride already, however, our machine is no stranger to a bit of rain and wind. It is Galway, after all, that puts the G in the Geec.

After Wednesday’s practice run ended early on Croaghpatrick, much soul-searching and analysis led us to two new tricks. On the car, we ran a slightly lower gear. Like dropping gear to climb a hill on a bike, this gives us more torque at the back wheel for the same torque coming in from the motor. Looking at it from the other point of view, we can get the back wheel torque (or traction) we need to pull up the hill for less torque at the motor. Less motor torque means less current and less load on the electronics. There is no free lunch, of course, and the price of this traction sandwich is reduced speed. There’s a balancing act in finding a gear that’s low enough to provide torque but high enough to keep us above the 25 km/h average around the track. Gear ratio has a big impact on efficiency too, but Friday was about playing safe, putting a score on the board and getting some knowledge of this track.

The new driving strategy called for a flat-out approach on the long slightly downhill straight that leads to the base of the hill. In theory, this has two benefits – sheer momentum to carry up the hill, and higher motor speed for the first part of the hill, resulting in lower current. This would mean higher speed than we would need or like on that section, but should help up the hill.

With preparations complete, we began to queue for our competition run. Then we queued some more and continued on to advanced queuing, further queueing and bonus queuing. This routine was brightened by a call from NUI Galway asking if we’d like to do a facebook live broadcast. Without hesitation, Daire took on the roles of producer, director, cameraman, and broadcast engineer, while Parnell slotted into the presenter’s role with the smoothness of Terry Wogan. Fun ensued. We tried to capture the energy of this engineering festival, and show what we’re doing and experiencing over here. You can watch it here.

Waiting on the hill

Waiting on the hill

After more weather-induced delays, Niamh strapped in and rolled to the start line. Most of the team sprinted from there to a viewing point on the slopes of Croaghpatrick to wait. It turned out to be, or felt like, a very long wait. But the Geec swept into view on a classic racing line around the bend into the base of the hill, and began the climb. We put on a brave cheer as Niamh rolled by beneath us and then watched in silence as the car gradually decelerated, manoeuvred around a stalled competitor, and after an eternity, crested the hill. Problem solved! Niamh continued to finish the first lap in 5 minutes 1 second, well inside the 5:22 maximum pace. Again on lap 2 she made it look easy.

The Geec powers up Croaghpatrick

The Geec powers up Croaghpatrick

Then bad news from Shane, in voice contact with Niamh – she was forced to stop. We can now reveal the shocking truth: the accelerator pedal fell off. Having conquered Croaghpatrick, the attempt was blown by a loose nut. Niamh came back to base in the passenger seat of a golf buggy, with most of the Geec on a trailer behind and its accelerator pedal in her hand. It’s becoming clear that total utter calm is one of an Eco-marathon driver’s many important qualities. We are fortunate to have two drivers with buckets of it.

The competition session was still live so we got straight back into the starting queue. Team Geec’s very best spanner people dealt with the Nut Issue and gave every other nut, bolt and screw a going-over the like of which hasn’t been seen since Apollo 11.

There's that driverly calm

There’s that driverly calm

Within half an hour Niamh was on track again. After 2 or 3 more passes up the hill it began to look too easy and we wandered off to watch on other parts of the track. We counted down the laps and checked the times. With laps 2-7 consistently 10 s ahead of schedule, she built up a buffer that allowed her to coast home for a leisurely low-energy final lap of 6 minutes, coming in 14 seconds inside the allowed maximum of 43 minutes. Precision!

approach

Collecting that sweet kinetic energy on the long approach to the big hill

After what felt like endless post-race inspections, we got a score: 157 km/kWh. Mixed emotions. On the face of it that’s a lot less than last year’s finishing score of 287. Then again the top score has dropped from around 850 in flat Rotterdam to the mid 600s – in proportion with our drop. Meanwhile, there’s a lot we can do before our next run to raise that score by a big chunk. That was our first run, in a conservative setup born of respect for the Hill of Pain. Now we know what’s needed to beat the hill, and we can start to be precise.

At the close of the session, the completed scoreboard put our result in context. We were in 16th place out of 17 teams who achieved a scoring run. We were in 16th place of about 50 entrants, some of whom did not clear technical inspection. About half of the 50 cleared inspection but didn’t complete a run for some reason. We witnessed many of them parking on the hill. As we said before: this is an exceptionally tough challenge in what was already a world-class competition. We’re happy to be among that group of 17 who are still at the races. At the time of writing, after another full session on Saturday morning, only 3 more teams have completed a run. From the intense lessons of the last few days we have good reason to believe that we can bump our score up, and not just by a few incremental points. We have two more chances to do so.

Unofficial official team portrait

Unofficial official team portrait

It’s 3.30 on Saturday and the next session is about to begin. As usual: twitter.com/theGeec for quickest updates in the heat of racing, facebook.com/theGeec.ie, and sem.pksoft-live.com (team number 334) for live lap times.

Josefine Kristy Web Developer

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Website: http://www.spikeincor.eu