Passenger Trains > Denver's Airport Line

Had chance to ride Denver's heavy rail airport line today....find it hard to believe that they are still are using flag man at all the grade crossings...thought they would have fixed problem by now

Posted from Android

Marty Harrison
Knob Noster, MO

You know how it is Marty. You gotta find the problem, come up with a solution, implement the solution and then see if it works.
And that all takes time!

PHall Wrote:
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> You know how it is Marty. You gotta find the
> problem, come up with a solution, implement the
> solution and then see if it works.
> And that all takes time!

You left out form committees and hire consultants.

Realist Wrote:
-------------------------------------------------------
> PHall Wrote:
> --------------------------------------------------
> -----
> > You know how it is Marty. You gotta find the
> > problem, come up with a solution, implement the
> > solution and then see if it works.
> > And that all takes time!
>
> You left out form committees and hire consultants.

That's part of "find the problem".

it still is a great way to get to downtown Denver.   Arlen

That I would agree...it is a great ride and Denver really stepping forward with their rail systems

Posted from Android

Marty Harrison
Knob Noster, MO

Seems strange that a brand new system would have flagmen after starting to haul passengers.  Wouldn't the crossings be something that works right away?

Daylight

My understanding is that it has to do with the new PTC software.  Evidently every train must "acknowledge" every crossing gate along the route through electronic communication with the crossing signal.  In some cases the acknowledgement doesn't happen right away, so the train must slow down.  Not sure if they had problems with gates not lowering in time.

 

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casco17 Wrote:
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> My understanding is that it has to do with the new
> PTC software.  Evidently every train must
> "acknowledge" every crossing gate along the route
> through electronic communication with the crossing
> signal.  In some cases the acknowledgement
> doesn't happen right away, so the train must slow
> down.  Not sure if they had problems with gates
> not lowering in time.
>

That's pretty close.  There are "traditional" crossing approach circuits on RTD commuter rail but they are physically placed some distance from each crossing based on the max possible speed at that location.  This of course means that if your train is not at max speed, the gates will be down longer than necessary.  RTD is using a new wireless crossing technology that's part of PTC where the train communicates its estimated arrival time to the crossing.  The crossing will start a countdown timer and activate when it hits 0 (which may be after the train's passed the approach circuit).  The goal is to minimize the activation time while still meeting FRA requirements.  Of course being the first to use it means RTD gets to work the bugs out.

niagara484



Edited 1 time(s). Last edit at 08/27/16 22:22 by niagara484.

Transportation of all kinds is way too dependant on computers. Witness the recent meltdowns at Southwest and Delta airlines. As I recall, ticketing seemed to work just fine before the computers took over. Somehow people got checked in and planes even flew. Now everything grinds to a halt with any sort of failure. 

Reminds me of when the LA Metro Gold Line between Pasadena and Azusa was being tested last year.  Until all the grade crossing signals were thoroughly tested under various likely and unlikely conditions, LA County Sheriff's deputies with patrol cars provided backup protection for the crossings.  Drivers may not respect crossing signals, but they pay attention to black and white cars with flashing red and blue lights.

And, every grade crossing is manned with 2 flagmen for the 20 plus hours a day the RTD commuter rail is in operation.

Marty Harrison
Knob Noster, MO

andersonb109 Wrote:
-------------------------------------------------------
> Transportation of all kinds is way too dependant
> on computers. Witness the recent meltdowns at
> Southwest and Delta airlines. As I recall,
> ticketing seemed to work just fine before the
> computers took over. Somehow people got checked in
> and planes even flew. Now everything grinds to a
> halt with any sort of failure. 

Given current volumes, I'd be surprised if any airline even considered writing tickets by hand. Or computing fares with an abacus.

Lackawanna484 Wrote:
-------------------------------------------------------
> andersonb109 Wrote:
> --------------------------------------------------
> -----
> > Transportation of all kinds is way too
> dependant
> > on computers. Witness the recent meltdowns at
> > Southwest and Delta airlines. As I recall,
> > ticketing seemed to work just fine before the
> > computers took over. Somehow people got checked
> in
> > and planes even flew. Now everything grinds to
> a
> > halt with any sort of failure. 
>
> Given current volumes, I'd be surprised if any
> airline even considered writing tickets by hand.
> Or computing fares with an abacus.

When the art of the abacus was still widespread and practiced, adept users could equal or beat the calculator for some transactions. :-) There's actually a logical reason for that, but it's off topic.

Out of ignorance, most people don't realize how complicated software-driven systems really are. Just because there are no gears, levers, and linkages don't mean they are "simple." Some management decisions, especially deadlines, are driven by that ignorance. Looks like a case of insufficient testing.

Add to that the high tech philosophy of "ship it now, and fix it later." That's OK for personal computers and mobile electronics, where it's now fashionable to "download updates," but I don't think that's wise for systems carrying plenty of energy like transportation - Teslas electric cars, and trains included.

If all these flagman get deducted from their operating budget, this rail line will look like a boondoggle that should have been an express bus. Simple, fixed, traditional grade crossing circuits would have worked fine.

andersonb109 Wrote:
-------------------------------------------------------
> Transportation of all kinds is way too dependant
> on computers. Witness the recent meltdowns at
> Southwest and Delta airlines. As I recall,
> ticketing seemed to work just fine before the
> computers took over. Somehow people got checked in
> and planes even flew. Now everything grinds to a
> halt with any sort of failure. 

Computers are not the issue.  The problem is when management makes decisions on system/software deisgn
without consulting their technical experts.  I think a lot of software designers will agree with me that too often
management dictates which tools will be used, rather than selecting the proper tool for the job.
 

andersonb109 Wrote:
-------------------------------------------------------
> As I recall,
> ticketing seemed to work just fine before the
> computers took over. Somehow people got checked in
> and planes even flew. Now everything grinds to a
> halt with any sort of failure. 

That was when flying was for the privileged few, today's low cost airlines rely on computer technology to deliver low fares.