ssiguy2
Senior Member
I did a little digging and found an article from Occasional Coherent from 2018 on the "physics of train acceleration". It was quite interesting and it shows exactly what we are looking for.
The study was sponsored by the MBTA to look at the potential of their new Boston regional rail network and what system and technology would work best. It compared a Flirt EMU {NOT DMU} with 500 PAX with a diesel loco pulled 3 car bi-level {same ones they use in Toronto} that also has 500 PAX and an 9 car bi-level diesel loco train with 1600 PAX, for acceleration. Here are the stats from a full stop to how many seconds it would take for each train to reach a certain distance in feet:
EMU..................50 seconds, 3000 ft, ...........100s, 8400 ft............150s, 14,400 ft
3 car Loco........50 seconds, 2000 ft.............100s, 7000 ft............150s, 13,000 ft
8 car Loco........50 seconds, 1000 ft.............100s, 4000 ft.............150s, 8000 ft
That is a very noticeable difference between a 3 and 9 car bi-level and shows after the first 100 seconds, there is no difference between the EMU & the 3 car loco. Considering Toronto runs 12 car trains,, the difference would be even greater. It also stated that the deacceleration rates were roughly inline with the difference in acceleration rates for each technology/system. The EMU wins that contest as well but the smaller loco still maintains a healthy gap between the much longer trains.
The study was sponsored by the MBTA to look at the potential of their new Boston regional rail network and what system and technology would work best. It compared a Flirt EMU {NOT DMU} with 500 PAX with a diesel loco pulled 3 car bi-level {same ones they use in Toronto} that also has 500 PAX and an 9 car bi-level diesel loco train with 1600 PAX, for acceleration. Here are the stats from a full stop to how many seconds it would take for each train to reach a certain distance in feet:
EMU..................50 seconds, 3000 ft, ...........100s, 8400 ft............150s, 14,400 ft
3 car Loco........50 seconds, 2000 ft.............100s, 7000 ft............150s, 13,000 ft
8 car Loco........50 seconds, 1000 ft.............100s, 4000 ft.............150s, 8000 ft
That is a very noticeable difference between a 3 and 9 car bi-level and shows after the first 100 seconds, there is no difference between the EMU & the 3 car loco. Considering Toronto runs 12 car trains,, the difference would be even greater. It also stated that the deacceleration rates were roughly inline with the difference in acceleration rates for each technology/system. The EMU wins that contest as well but the smaller loco still maintains a healthy gap between the much longer trains.
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