London Banter - View Single Post - Inside the Vivarail D-Train

[email protected] · July 6th 17, 11:10 AM posted to uk.railway,uk.transport.london

On Thu, 06 Jul 2017 12:01:03 +0100
wrote:
On Thu, 6 Jul 2017 08:46:18 +0000 (UTC), d wrote:

On Thu, 6 Jul 2017 06:33:09 -0000 (UTC)
Recliner wrote:
Jan-Martin Hertzsch wrote:
On 07/04/2017 04:17 PM, Someone Somewhere wrote:

... D stock could be quite bouncy ...

It's been a long time since I last rode the Underground,
and even longer since I travelled on D stock, but I'd
attribute the bumpiness of the ride less to the trains,
but more to the track. I mean, it is very, very busy and
therefore wears out rather quickly, in particular around
points. Also, the D stock is lighter than the A and C stock.

The S stock certainly rides a lot better than the D stock on exactly the
same track. I think one other issue with the D stock is the longer car
length, meaning the car ends have a lively ride.

The opposite is true. The longer the wheelbase of a vehicle, the less the
vehicle body vertical angular deflection due to a bump of a given size.

Won't the overhang beyond the bogie centers also have an affect?

Obviously the longer the overhang from the pivoting bogie the more the floor
will shift up and down. But a shorter wheelbase will amplify it. I suppose
its a case of which has the biggest effect.

--
Spud