Monday, September 24, 2012

Remote Control

With the new track construction at union station, and with the help of the railroaders and hard core railfans who write Wikipedia articles, it has been possible to identify components of the remote systems that regulate passenger trains. I'm sure that  our Anonymous Amtrak reader,  or others more knowledgeable, will correct my mistakes.

As trains leave  LA Union Station, they pass a box with a  light that says "CTC begins".  I believe CTC stands for Centralized Traffic Control, which essentially means there is  a dispatcher who functions like an air traffic controller to regulate signals and switches remotely.  This  ensures the smooth running of trains particularly through regions of single track, without relying on the train crews or local towers to keep track of the traffic individually  to manage the switches.

I assume that the blue structures bolted onto the new tracks at LAUS are magnets associated with the CTC, since they are right next to the light box.

Or are they part of the Automatic Train Stop system?  That is required on passenger trains in certain regions to allow them to go as fast as 90miles an hour. It works via a magnetic shoe on the front right of the locomotive (or cab car) to pick up a remote signal.   This conveys a  signal d to the engineer who has 8 seconds to acknowledge that he got it, before the brakes automatically deploy. 

You can see the shoe in the picture to the right--it is the lowest structure you see, hanging off the truck to run at the outside of the track.

Apparently this is found in only parts of Amtrak's service area, including the Pacific Surfliners.  So, any locomotives from elsewhere in the system that "sub in" for the PacSurfliner engines, have to be fitted with this shoe. The long distance locomotives from the Southwest Chief also have ATS shoes, so that's probably where our "Gennies" come from.

This is what comes of walking up and down the platform while waiting to board the train, and noticing odd things on tracks and engines.

Update:  our friend Anonymous in the comments says that the blue bits are
 insulated joints. The signal system functions via low-voltage electrical currents which run through the rails, each "block" of track is independent, so at each signal the tracks need to be segregated electrically to differentiate the blocks in the computer.
Otherwise, he says this is pretty accurate.  Praise from the Pro is praise indeed!  :-)

Thursday, September 20, 2012

More woodpile haiku

The train sits and waits
While the sun sinks down
Shadows drift o’er the woodpile

Previous entries in the waiting-at-the-woodpile series here.

Tuesday, September 18, 2012

Progress on new platform at Union Station (updated)

I've told you before about the renovation of Union Station is underway to facilitate its conversion from a "stub" station to one with "run through" tracks for more efficient travel. Right now, all trains, whether coming in or leaving, must pass through a narrow "throat" and if headed south, navigate a 180° turn.  This is part of the reason why the Amtrak operates in a push-pull configuration, where essentially it reverses into the station from San Diego or Goleta, with the engine pushing rather than pulling.  (The other reason is that there is no wye in Goleta or San Diego to turn the train around, so it's not clear that this will eliminate push-pull trains, which are not popular.)

The raised structure on the left is the old cap over the ramp
 The first step is the rebuilding of platform 7 and reactivation of tracks 13-15.  This has been fun to watch as they have done a brilliant job of recreating the look of the other platforms with their "butterfly" canopies.  You can see more pictures on my previous post.

 The original ramp and stairways were "capped off" when the platform was inactivated, so they've also had to re-open the connections to the tunnel below.  I wonder how many people noticed that there were archways over the walls at the east end of the tunnel, indicating that there used to be more platform?  Based on the arches, it also looks like there was an 8th platform with connections below.  (Update: Mark, posting in the comments to this post, says that was indeed the case.)

Along with building the platform, they also had to lay the track, and that was fascinating to watch.  But yesterday, I noticed that all the big track machines are gone, so the tracks must be ready.  There's still some painting going on but the benches are in place and it looks close to finished.  The attention to detail is nice;  for example, the light fixtures on poles at the east end of the platform have the same elegant design with spiky finials as the ones on the street below.

The picture below was taken yesterday from track 12, and shows the new platform looking clean and fresh next to the old one.  Of course, once this activates, there will be more construction as they begin the biggest part of the project, building run-through tracks over the 101 freeway.

The new platform as seen from Track 12.