Michael Ross via EV wrote:
The gravitational energy you put into a vehicle climbing a hill, comes back
to you on the downhill side. The effect of weight is often overestimated
for this reason.
That works well for cars; but not for trains. Diesel-electrics have no
means for regenerative braking. Rolling resistance is so low, and weight
is so high that it's the weight that dominates the power requirements.
They have to expend a huge amount of fuel to climb a big hill, and don't
get it back going down the other side.
A diesel locomotive has huge braking resistor grids on the roof under
the big fans. When the're going downhill, you can see them glowing
red-hot to dissipate as much of the braking energy as possible as heat.
But electric locomotives *can* regenrate power back into the rails.
Electric railoads and commuter trains will schedule them so one is going
up down the hill at the same time another one is going up the hill to
balance the power.
Lee
--
Ring the bells that still can ring
Forget your perfect offering
There is a crack in everything
That's how the light gets in.
-- Leonard Cohen, from "Anthem"
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com
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