How is Metro unable to anticipate or detect a rail problem like that without running a train full of customers over it to the point the train falls off the tracks?

by EPrince on Jul 9, 2012 8:38 am • link • report

Psst...just a reminder it's no longer the BOEE, they dropped the E for ethics.

by No Ethics on Jul 9, 2012 8:49 am • link • report

Would it be possible to install strain gages on the rails at key locations within the system, then reducing the train speeds when the strains approach levels that would suggest a heat kink is possible?

This is a buckling phenomenon, which occurs only when the compressive load exceeds a critical value. By monitoring the rail strain, we could predict when kinds are possible.

Is this something they already do?

by Michael Perkins on Jul 9, 2012 8:52 am • link • report

Will NPS loosening restrictions change anything locally?

by selxic on Jul 9, 2012 8:52 am • link • report

As usual, someone else has already had the same idea:

http://www.fra.dot.gov/downloads/research/rr0831.pdf

by Michael Perkins on Jul 9, 2012 8:57 am • link • report

Or, instead of using a ridiculously expensive (and largely unproven) technology, you could have the trains slow down during very high temperatures or they could use jointed track instead of continuously welded rail on above ground sections.

by elmothehobo on Jul 9, 2012 9:09 am • link • report

Is their any information that shows the use of long spans of continuous welded rail, as opposed to the old-fashioned method of having rail joints every few tens of yards, leads to an increase in heat-related rail warping?

by ksu499 on Jul 9, 2012 9:15 am • link • report

@Kksu499:

There is a lot of work on this. Welded rail can fail longitudinally, leading to disaster. See http://dspace.mit.edu/bitstream/handle/1721.1/26829/25034915.pdf?sequence=1

by goldfish on Jul 9, 2012 9:22 am • link • report

An answer to my own question: apparently heat warping was first noted as an issue in the 1950s as welded rail began to replace jointed rail. http://www.baltimoresun.com/bal-heattracks30,0,1642549.story

So, yes, there is a direct correlation, and probably causality.

by ksu499 on Jul 9, 2012 9:28 am • link • report

Thanks for the hard work and I love the site. I noticed a few typos in this article:

temporally = temporarily
damgage = damage
planed = planned
City Market an O = City Market at O
latter = later

by pedant on Jul 9, 2012 9:33 am • link • report

In light of our ground water runoff fiasco (the $2.6+ Billion tunnels which will cost each of us $50-$100/month) you would think there would be more discussion here of green streets, green alleys, etc. There isn't.

Other places have already realized that pouring more concrete over every blade of grass isn't smart growth:

http://www.ccap.org/docs/resources/989/Green_Infrastructure_FINAL.pdf

http://www.werf.org/liveablecommunities/toolbox/gst_promote.htm

http://greengaragedetroit.com/index.php?title=Green_Alley_Research_Center

http://streetswiki.wikispaces.com/Green+Streets

Notice that Vancouver has alleys with a median of porous pebbles. Chicago has developed a whole "Green Alleys" program. And the DC-based Center for Clean Air Policy commends several of the biggest urban centers for their work- but not DC.

FWIW the old Rhode Island Avenue streetcar line had a dedicated right-of-way which ran over grass and I'm sure several other lines did too. Alleys and the paved parking pads in rear yards also account for a huge portion of pavement in DC.

If the impending huge bill we're about to pay for not having a green program in DC isn't motivation, one wonders about DC.

by Tom Coumaris on Jul 9, 2012 10:27 am • link • report

Proponents say the legislation is aimed at stopping local startups from moving out of the city before the companies go public so founders can get a lower tax rate on the sale of shares.

Is there any evidence that this is an actual problem? My guess is that founders are more concerned with maintaining growth momentum for their startups than a 4.6% difference in their cap gains tax rate. By moving, they risk squandering valuable management attention (and losing key personnel) by moving to a new jurisdiction right before going public. An operational hiccup caused by focusing on the logistics of a move would be far more costly to a startup than a few extra percentage points on a one-time cap gains tax.

Instead of providing tax rebates to entrepreneurs who are about to make a bundle on cashing in their startup, DC should spend the money on improving tech education (or at the very least, getting out of the way of local universities that are already trying to do that).

by Falls Church on Jul 9, 2012 11:04 am • link • report

Wasn't there a green alley bill passed in the council a while back? And I remember reading about the permeable pavement project in Mt. Rainier (or near there, but that's md and not DC) a while back. I'd imagine as they learn things about that project we'll see more about it.

by drumz on Jul 9, 2012 11:09 am • link • report

@drumz-It was Mt. Rainier. They tore up an old parking lot and replaced it with another parking lot(not needed, but it was "free" money), but with permeable pavers. They also tore up the entirety of the alley adjacent to my house but only put in pavers for 3/4ths of the alley due to budget constraints. It's meant to correct their approval years ago of the paving of an adjacent parking lot that was previously gravel(though it should not have been approved) It's made a massive difference in run off from the two parking lots next to my house (although nothing could contain the amount of water we received from that microburst 2 weeks ago). My back door neighbor is not so happy though as now bits of torn up asphalt are washing into his garden. The town of Edmonston also installed a "Green Street" on Decatur with rain gardens in the bulb outs (http://edmonstonmd.gov/GoingGreen.html)

by thump on Jul 9, 2012 11:54 am • link • report

I'm not 100% sold on the permeable sidewalks and paving as another commenter noted they eventually get clogged (and that rubbery stuff doesn't seem to stay put either). But that's just one small option in a green streets/alleys program.

We can easily determine where (in the Old City mostly) the runoff problem occurs and mandate or even pay for taking up part of the concrete/asphalt and replacing it with grass or pebbles. Alleys and parking pads are the obvious first steps.

Instead we seem headed the opposite way. The alley beside my house was porous cobblestone for over 100 years. DC just asphalted over it about 10 years ago. In the past 10 years half the rear yards in my block have been concreted over for resident parking. 10 years ago the gravel alley behind my house was concreted over. And of course there's that new 2 story underground garage next door sump pumping underground water into the sewer.

Now self-proclaimed "smart growth" people want to pave over McMillan Park & Reservoir, the front lawn of Springarn High and any other permeable ground they can build on.

We're slow learners.

by Tom Coumaris on Jul 9, 2012 12:40 pm • link • report

MWAA finally caves in to legal reality...no more union preferences in Virginia Silver Line Rail Project. Glad that scandal is over: http://www.wtop.com/41/2892068/Concession-made-in-Dulles-Rail-project-

by pelham1861 on Jul 9, 2012 4:27 pm • link • report

Is there a particular reason you're bringing up last month's news?

by Alex B. on Jul 9, 2012 4:41 pm • link • report