[ale] [OT]atlanta beltway need this!!!

[Jeff Hubbs]

Geoffrey wrote:
> Greg Freemyer wrote:
>   
>> On Fri, Nov 6, 2009 at 11:37 AM, Doug McNash <dmcnash at charter.net> wrote:
>>     
>>> ---- Geoffrey <lists at serioustechnology.com> wrote:
>>>
>>>       
>>>> So maybe someone can define the difference?  Or maybe simply define
>>>> 'light rail?'
>>>>
>>>>         
>>> MARTA is light rail, is it not?
>>>       
Heavy.
>
> I thought maglev provided reduced friction but also forward energy?
>
>   
I'm not sure what practical systems do but I think the whole point, from 
diagrams that I remember, is to have the magnetic apparatus lift, guide, 
*and* move the train.  One diagram I recall had a sidelong "rail" onto 
which the train both pushed from above and pulled from below using a 
wicked control system to keep the train stable in real-world 
conditions.  Think about it - you've got to deal with increasing and 
decreasing grades, turns (some of which would be banked), wind, shifting 
load...and it gets worse.  You don't want to have a push-only system 
that uses simple repulsion to lift the train when the tractive force you 
get might depend on ride height - can you imagine having the whole train 
start pogo-sticking front-to-back because of differences in tractive 
force from car to car?

To my mind, the risk, cost, and complexity of maglev isn't sufficiently 
justified by the speed.  I want monorail. :)