[PRCo] Fw: Maximum speed of low floors

[Jim Holland]

wrote in message news:...
 > In article
 > <61203fe5-5266-4911-9899-917ce64a6cd2 at c30g2000hsa.googlegroups.com>,
 > Crown-Horned Snorkack wrote:
 >
 > > Ah, I see. For passenger comfort, there is no difference whether the
 > > train accelerates at 1 m/s/s from 10 km/h to 20 km/h, 110 km/h to 120
 > > km/h or 410 km/h to 420 km/h, but the power needed to accelerate is
 > > different and the power needed to overcome air resistance is even more
 > > different. Therefore, a train needs high floor for the volume space
 > > that the engines need. Correct?
 > >
 > > But this should also restrict wide gauge low floor designs... or not?
 >
 >
 > Currently the 100% low floor electric cars are limited to European
 > streetcar lines, which are fairly low speed.
 >
 > The partially low floor cars (such as are in the photos on the previous
 > link) where the center section is low and only the ends over the motors
 > are high have been built for higher speeds - into the 100 km/h range.
 >
 > So, it does restrict the type of low-floor design that is possible. The
 > 100% low floor streetcars in Europe have not been around very long
 > either. As time goes on, there may be a 100% low floor car capable of 
100
 > km/h or more, but for now the 100% low floor cars are very limited as to
 > what is being made.
 >
 > The much smaller motor power between the streetcar and the higher speed
 > car (the higher speed car may require a motor 8 times more powerful in
 > certain examples) allows the low floor to be built around the axles that
 > are powered, thus giving a low floor to all areas of the car. The
 > physically larger motor in the higher speed car makes it far more
 > difficult to put everything in place, and therefore many current designs
 > do not have a low floor over the powered axles if a speed of 100 km/h is
 > needed.
 >
 > --
 > -Glennl
 > e-mail hint: add 1 to quantity after gl to get 4317.
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Jim  Holland
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Studying Pittsburgh Railways Company (PRCo)
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..............................From 1930 -- 1950
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Pennsylvania  Trolley  Museum  (PTM)
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http://www.pa-trolley.org/
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N.M.R.A.
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http://www.nmra.org/