• blue switch over for overhead wires

  • Discussion relating to commuter rail, light rail, and subway operations of the MBTA.
Discussion relating to commuter rail, light rail, and subway operations of the MBTA.

Moderators: sery2831, CRail

  by efin98
 
CSX Conductor wrote:Airport used to be a good spot to do the switch because of the large number of passengers getting on and off....but Maverick seems to be getting to be busier than Airport. LOL
Maverick is second only to Government Center in terms of people boarding and exiting the train. Airport has a large number of people getting on and off the train, but that is much less than Maverick.

  by CJ
 
In all honesty (and i sorta hate to admit it) it SEEMS like ridership has gone up at airport after the "new and improved" station opened up, just SEEMS that way!

And i do remember not 2-3 yrs ago them switching the panto's over @ maverick..

  by CSX Conductor
 
Efin, I was only comparing the ridership of Maverick and Airport, as to determining where to do the power change with less delays due to the switch.

  by efin98
 
CSX Conductor wrote:Efin, I was only comparing the ridership of Maverick and Airport, as to determining where to do the power change with less delays due to the switch.
I agree with your point and I should have added more information.

I am thinking about this logically based on witnessing the change over first hand for years. It's easy to draw that with the large amount of passengers boarding and exiting at Maverick the natural delays would be much greater than at Airport. Airport only retards the train by a few seconds, Maverick can take up to a minute depending on the time of day. With those seconds lost at Maverick the T is able to change over from overhead to third rail and vice versa quickly and unnoticed since the doors are already open allowing passengers on and off the train. Airport the change over would actually cause a slight delay, a small one but still it does delay the train by a few seconds. However, if the ridership at Airport is sufficiant to equal or even exceed the time it takes to change over from third rail to catenart wire or from catenary wire to third rail then by all means the T has good reason to do it at Airport(heck, might be safer too with all those bags :wink: )

  by ctaman34
 
do you think they will pull down the wires between maverick and airport or no it's impossible

  by efin98
 
ctaman34 wrote:do you think they will pull down the wires between maverick and airport or no it's impossible
not likely, redundancy between Airport and Maverick is good.

  by Nasadowsk
 
Why don't they just change on the fly like Metro-North does on the New Haven line? That's always been a neat changeover - they do it while going ~ 50 mph. The HVAC cuts out for a second or two and thencomes on, but otherwise you don't notice it. And that's changing from DC third rail to 12kv AC too.

Are the third rail shoes live on the Blue Line cars when the train's on overhead power?

BTW - MN occasionally has a case where a pantograph pops up somewhere in the Bronx and hits a bridge. It's not supposed to happen but it does...

They have no plans to change the system any - I believe they've studied it and found that running wires to GCT is pretty much impossible due to clearences.
  by Robert Paniagua
 
Are the third rail shoes live on the Blue Line cars when the train's on overhead power?

I don't think that our 0600s are like that, with live third rail like the M-2/4/6 combination downthere, it's the other way around, the third rail shoes go out when the pan's are raised. That's most likely why the 0600s changeover happens when completely stopped.

I don't know about the 0700s (the next coaches in line), but they MAY have the same capabilities that the M2/4/6 possess in terms of the 3rd rail/catenary transition.