A good day to use CTA Alerts system
I was wiping sleep from my eyes at about 5 a.m. today, making coffee, when I heard my cell phone chime with the first of six CTA Alerts this morning:
4:59 a.m.: "No Rd Ln serv btwn N.Clybourn & Fullertn. Bus shuttle N. Ave to Belmont. Also use CTA bus service. Allow xtra trvl time."
Then two more in the next hour.
5:15 a.m.: "Southbound Red Line power is suspended b/t North Clybourn and Fullerton. Bus shuttles at No & Clybourn and Belmont."
And 6:01 a.m.: "SB Rd Ln trns travling to Loop on 'L' tracks instead of subway. Bus shuttle making Rd Ln stops N. Clybrn to State/Lake."
I was able to warn my daughter to leave early for high school and hopped into the shower earlier myself for what I figured would be a longer commute.
All these alerts came directly from CTA headquarters. Then this happy one came at 6:59 a.m. from ChicagoPoe: "Normal red line routing restored." Whoo hoo!
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Oh, and it was a Red Line derailment at Armitage that caused the problem.
ack! and here i just told my mom that nothing really ever happens on the el! she was terrified this past weekend when she and my dad came. she is just terrified of that darned train.
okay. some actual practical comments, though.
1. how does a train derail? 2. what happens when it does? i mean, to the passengers? or to the train? i mean, i know that the train automatically shuts off power and stuff, right? do they have to call a train tow truck to get it back on the track? is it always a function of going too fast? should i be re-routing this to "ask chicagoist?"
Posted by: jocelyn | April 06, 2006 at 03:46 PM
it'll derail for a variety of reasons, usually involving going too fast over a certain section of track. The train stays on the track because of the "lip" on the inside rim of the train wheels. The angle between this lip and the surface of the wheel gets worn down over time, as well as the angle on the accompanying section of track. if this angle gets to be too obtuse, the train has less "grip" to the track, and at high speeds, can jump off the rail.
The sharper this angle, the faster the train can go, especially around curves. periodically, these angles need to be reground, and eventually, the trains wheels need to be replaced.
another cause of derailment is of course an object on the rail that causes the wheel to jump off.
typically derailments will only involve a couple wheels on one train car, its not some huge spectacular explosion or anything of that nature. it could be a set of wheels somewhere in the middle of the train.
there are a few ways of dealing with it depending how bad it is....some involving a crane, some involving a process similar to jacking up a car and replacing a wheel/tire.
the train should still have power even if some wheels have derailed, as long as it is making contact with the power rail. however, the emergency brakes should also kick in. also note that the CTA would shut off power to that section of track to make it safe for passenges to climb down and walk down the track to safety.
all that said, i'm not sure what happened this morning, or what specifically caused it.
Posted by: vivalfuego | April 06, 2006 at 07:43 PM