High-speed vs conventional train

REPLY:

 

When you ride a HST, the feeling is similar to that being on a plane,

but with different ups and downs.

 

Now, to nit-pick (right spelling?) on the opinion below.

Work is force multiplied by a distance travelled.

The multiplier of 27 is on the force. The distance covered, in a unit of time, is 3x larger,

so the energy needed is 9x larger.

 

But the aero resistance is only a part of the total, so energy input will not grow that much.

Also, the aero shaping is better, which further descreases the multiplier.

The frequency-of-use factor will divide the result by 3.

 

Sincerely

 

Gregory from Oz

 

 

OPINION:

 

On Fri, Oct 29, 2010 at 11:53 AM, IRV FRUCHTMAN <ifaeng@yahoo.com> wrote:

>   Fellow Engineers,
>
> High speed trains are wonderful engineering feats, but I don't believe
> saving energy is one of them. As I recall from my school days: drag force=
 is
> proportional to speed squared and power (read energy) is proportional to
> speed cubed. Therefore a train moving at 300 mph, compared to a train at =
100
> mph,  uses (300/100)^3 =3D 27 times as much energy.  If the requirement f=
or
> the number of trains is reduced by 1/3 =96 to move the same number of peo=
ple -
> then the increased energy use is 27/3 =3D 9. Therefore, 9 times as much e=
nergy
> is required to move the same people/ load with a high speed train as
> compared to "low" speed train.
>
>
> Given a choice, I'll take an airplane.