I wonder if they included children in that, they are obviously lighter.
But many children don't count as passengers because they travel free with an adult (therefore invisible to statistics at time) and they often come with extra prams, bags etc. I would still recommend the higher average weight because it's always worth overestimating when it comes to calculating expected real fuel consumption.
If fuel or electricity is billed on estimated consumption rather than how much was pumped into the tank, of course you would use the underestimated weight!
It's a little bit of a tangent, but kind of related to the topic of train running costs still. I'll indulge you with a bit of "back of the envelope" physics - i.e. ignoring friction, wind resistance and so on.
Let's say you have a 150 ton train operating at 90 km/h - chosen from
a DMU type I ride at times - which is 25 metres per second, about 56 mph. Using the formula
K = 1/2 x mass x velocity squared, that train has a total of 47 MJ (megajoule) of kinetic energy at 90 km/h.
Let's say the station is elevated 10 metres (11 yards) from the normal track height - chosen
from a tram overpass/station I cycle over. Using the formula for gravitational potential energy
P = mass x gravitational constant x height you find that the train loses or gains 15 MJ when it goes up or down that slope.
Therefore instead of the brakes (could be a combination of regenerative, dynamic and friction) having to do 47 MJ of work to stop the train as they would need to for a station on the flat, they instead need to do only 32 MJ of work while the hill does 15 MJ. The same applies when leaving the station - to accelerate up to that same speed would require only 32 MJ of work to be done by the traction motors.
Even if you varied the mass of the train, the proportion of work done by the change in elevation would still remain the same as long as you kept the speed and height the same. If you vary the speed, the amount of work done by the change in elevation is the same but the amount of work required to brake/accelerate to/from a stop changes.
The beauty of this kind of solution is that it does not prevent express services passing through from carrying on at nearly full speed. Because energy is related to velocity squared, a train carrying on to the top without adding any braking effort would hit the top while still travelling at 75 km/h. Power could be fed in and the speed maintained, but with the catch of picking up even more speed on the way down the other side which may make it too fast, which is not a problem if regenerative braking is available.
A similar principle applies for motorway exit ramps. Ideally an exit ramp will slope up after it branches off the motorway, to help drivers who are "speed drunk" wash off speed.
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Nice idea, provided all trains that pass through the station will stop there - I'm not sure you'd want to design in a gradient like this for a station that has non-stopping services passing through.
Not really a problem, see the figures posted above. Dropping the speed a bit is not really an issue when you're headed back down again within seconds You wouldn't want your hump too high or steep because that would increase construction costs a lot, and in the case of normal railways (as opposed to underground) there is the issue of public amenity.
It's even less of a problem if regenerative braking is available. You power up to maintain cruising speed while ascending the hump, and use the regenerative braking to stop it going too fast while descending.
The presence of long freight trains without using an intelligent distributed traction system like Locotrol would make it a non-starter though.
I think the London Underground tube lines incorporate station humps like this too.
I expect that newer lines would, but are there any newer ones? I would have thought older lines would have been designed before this kind of thing was thought of, and that avoiding other subterranean pipes, cables etc would be the main factor affecting the vertical profile of the line.