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I mean, this is good news, but why was the efficiency of the system so misunderstood at the design phase? I hope someone's interested enough to find out!

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Ahoi! Participated to the development of a simulation tool for that purpose. Many factors need to be taken into account:

- The gradients of the track

- How agressively you want to drive at different time of the day

- How many trains

- The timing of the trains. When one train brakes, it can power another one that accelerates at the same moment

- The efficiency of the power chain

- The resistance model of the train

With so many parameters the results can be quite volatile. However, rule of the thumb in the business is that 30% saving can be achieved with good energy management. Hope this clarifies a little.

Update: bullet points

Interesting! Thanks for the great info. Do you know if anyone will have the opportunity to integrate observations into the model so it can continue to improve?

We did use actual data from existing lines to measure the gap between our models and reality. We were +/- 5% accurate.

Maybe they didn't factor in ridership on certain part of the track gradient, which would lead to more regen braking than expected?

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