If a train de-rails ...

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

Moderators: sery2831, CRail

Re: If a train de-rails ...

Postby typesix » Mon Feb 27, 2017 11:45 am

typesix
 
Posts: 626
Joined: Fri Mar 12, 2004 11:23 am
Location: Boston

Re: If a train de-rails ...

Postby millerm277 » Mon Feb 27, 2017 12:26 pm



The MBTA also runs the busiest light rail system in the country. All else being equal, it ought to be leading the nation in derailments. And per-passenger, it has vastly fewer derailments than the systems it's ahead of.

#3 is New Orleans. Which has 22,000 daily riders, and they had 6 derailments.

That seems vastly more concerning than the MBTA with 10x the ridership and a far higher quantity of service/trips having 8.
millerm277
 
Posts: 86
Joined: Thu May 24, 2012 1:47 am

Re: If a train de-rails ...

Postby jboutiet » Mon Feb 27, 2017 1:43 pm

Putting it into a different perspective, there are 20x more derailments per passenger mile in NOLA vs. the MTBA.

(8 per ~1.877 billion passenger miles for MBTA, 6 per 72 million for NOLA; using the 2015 APTA fact book)
(and yes, I know I'm mixing measurements... but the magnitude of the result is still valid)
jboutiet
 
Posts: 63
Joined: Mon Jan 29, 2007 1:59 pm

Re: If a train de-rails ...

Postby BandA » Mon Feb 27, 2017 3:38 pm

NOLA cars are about 100 years older than the Breda cars, so NOLA gets a pass. T should add rubber tires to the trolleys, then if the de-rail they can just keep going :wink:
User avatar
BandA
 
Posts: 1716
Joined: Thu Oct 11, 2012 11:47 am

Re: If a train de-rails ...

Postby johnpbarlow » Tue Feb 28, 2017 7:46 am

Love the proofreading at WBZ - CBS Boston:

Eight MBTA vehicles–including six Green Line trollies–derailed last year, according to data from the National Transit Database.


"Trollies?"

http://boston.cbslocal.com/2017/02/27/mbta-derailments-leads-nation-green-line-light-rail/
johnpbarlow
 
Posts: 1554
Joined: Fri Mar 12, 2004 12:50 pm

Re: If a train de-rails ...

Postby BandA » Wed Mar 01, 2017 2:06 am

Trollies is the plural of Trolly. Duh!

Trollies doesn't pass the basic spellcheck however... Must be a technical word.
User avatar
BandA
 
Posts: 1716
Joined: Thu Oct 11, 2012 11:47 am

Re: If a train de-rails ...

Postby johnpbarlow » Wed Mar 01, 2017 5:20 am

BandA wrote:Trollies is the plural of Trolly. Duh!

Trollies doesn't pass the basic spellcheck however... Must be a technical word.


Look up "trollies" in the Urban Dictionary - certainly not what article's author had in mind! ;-)
johnpbarlow
 
Posts: 1554
Joined: Fri Mar 12, 2004 12:50 pm

Re: If a train de-rails ...

Postby CRail » Wed Mar 01, 2017 6:38 am

BandA wrote:NOLA cars are about 100 years older than the Breda cars, so NOLA gets a pass. T should add rubber tires to the trolleys, then if the de-rail they can just keep going :wink:

If age of equipment makes it susceptible to derailments, explain why zero of the MBTA's derailments were PCCs.
Moderator: Massachusetts Bay Transportation Authority
Avatar:3679A (since wrecked)/3623B (now in service as 3636B).
User avatar
CRail
 
Posts: 2105
Joined: Tue May 18, 2004 8:27 am
Location: Eastie

Re: If a train de-rails ...

Postby The EGE » Wed Mar 01, 2017 10:45 am

Because the PCCs make less than one-tenth the train miles - and one-twentieth of the vehicle miles - of the Green Line?
"Give me an unobstructed right-of-way and I'll show them how to move the earth!"
User avatar
The EGE
 
Posts: 2448
Joined: Wed Feb 16, 2011 6:16 pm
Location: Waiting for the C Branch

Re: If a train de-rails ...

Postby CRail » Wed Mar 01, 2017 3:28 pm

Em... train miles, vehicle miles, how do those compare to distance miles? At least 2 of 7 cars are out on the line from 5am to 2am daily. Train miles, track hours, trips per capita Image don't have anything to do with the fact that the cars are more reliable and can operate over track a Type 8 couldn't park on without derailing. Age of equipment has exactly nothing to do with derailing, wheel profiles are maintained the same.
Moderator: Massachusetts Bay Transportation Authority
Avatar:3679A (since wrecked)/3623B (now in service as 3636B).
User avatar
CRail
 
Posts: 2105
Joined: Tue May 18, 2004 8:27 am
Location: Eastie

Re: If a train de-rails ...

Postby BandA » Wed Mar 01, 2017 4:38 pm

PCC cars are much more modern than the NOLA cars. They were designed with the knowledge of all the improvements over the previous 50 years. They were built by high-volume, skilled manufacturers. By the time of the LRV and Breda cars they were literally reinventing the wheel.
User avatar
BandA
 
Posts: 1716
Joined: Thu Oct 11, 2012 11:47 am

Re: If a train de-rails ...

Postby CRail » Wed Mar 01, 2017 6:12 pm

Most of my experience with streetcars is with equipment exceeding a century in age and with much the same technology as the New Orleans green cars. Except in cases wherein a wheel or axle is defective, the vehicle is NOT more susceptible to derailments because it's old. Poor track maintenance, yes, extremely poor vehicle maintenance (for example a frozen axle or a seized bolster bearing), sure, but the age of a vehicle in regular service, absolutely not. Vehicle design is the factor here, not age. If the green cars are inferior in design, which I don't believe they are, then that could be a factor, not their service tenure. The Type 8s have a wimpy air suspension system and a center truck with 4 independent wheels incapable of maintaining a perfect distance of 4' 8" flange to flange. LRVs have not been that problematic, save for some teething with the Boeings when articulation was a new concept to us (spliced cars don't count as they were not remotely similar in design) and the top heavy Type 7s with their rocking issue. Type 7s were about as well designed as the PCCs and because of that, neither derail with any regularity regardless of how much farther into the past their build date ventures.
Moderator: Massachusetts Bay Transportation Authority
Avatar:3679A (since wrecked)/3623B (now in service as 3636B).
User avatar
CRail
 
Posts: 2105
Joined: Tue May 18, 2004 8:27 am
Location: Eastie

Re: If a train de-rails ...

Postby ExCon90 » Thu Mar 02, 2017 4:01 pm

BandA wrote:Trollies is the plural of Trolly. Duh!

Trollies doesn't pass the basic spellcheck however... Must be a technical word.

Maybe it has to be spelled that way if it receives public monies?
ExCon90
 
Posts: 3376
Joined: Thu Sep 18, 2008 1:22 pm

Re: If a train de-rails ...

Postby Disney Guy » Sat Mar 04, 2017 10:10 am

Maybe it has to be spelled that way if it receives public monies?


The transit industry and mass media had to come up with another word for "trolley" in order to gain favor from the public and therefore get public monies to rejuvenate trolley systems and, as history played out, build new ones. The term they came up with was "light rail."

Someone mentioned that the Type 8 center sections had a tendency to "crab" down the track including on the straightaway. This forces the wheel flanges to do much more to keep that section on the track compared with more conventional swiveling trucks (bogies) and fixed truck (4 wheel) cars using wheelsets with rigid axles. The same problem might occur with standard swiveling trucks if the side pads bind on the undercarriage due to worn or damaged parts or inadequate lubrication. (Model railroad cars don't have such side pads; the truck contacts the car body only via the kingpin.)

I would be interested in finding out whether some of the acceptance tests including for the Type 8's included the ability to detect when a wheel "threatened" to derail but no derailment took place. Also finding out whether simply adding a modest amount of dead weight to the center section greatly reduced the tendency to derail.
(To the theater stage manager) Quit twiddling the knob and flickering the lights while the audience is entering and being seated. (To the subway motorman) Quit twiddling the knob and dinging the doors while passengers are getting off and others are waiting to board.
User avatar
Disney Guy
 
Posts: 783
Joined: Thu Apr 19, 2007 9:10 am
Location: Nashua, NH

Previous

Return to Massachusetts Bay Transportation Authority (MBTA)

Who is online

Users browsing this forum: Echo33d and 6 guests