Tag Archives: maintenance of way

In with the new, disregard the old

Due to popular demand, here are more construction photos showing the work being done at the Jackson turnaround and the facility expansion at Ruby Junction.

First, the work being done by Ruby:

And Jackson, where Orange Line trains will continue to Milwaukie:

And while it’s great and all to see the work for the Orange Line coming along, I can’t help but wish the same focus was put on maintaining the existing alignment. Remember that big to-do this past March? Long story short, frontline workers had been trying to address long-standing safety issues at TriMet, including damage to the alignment that had gone unrepaired for months (example – the switches just west of the Lloyd Center platform, pictured here in July of 2012 and again in January 2013 with no repairs made). Nothing was being done internally, so the union brought it to the media, which then led to ODOT announcing an inspection. Cue a flurry of activity at TriMet which largely consisted of throwing asphalt on everything to patch the alignment up before the inspection (here are the same switches in mid-March 2013). As a result, the ODOT report didn’t find any major safety concerns. TriMet claimed this as a victory and accused the union of making up safety issues to draw attention away from the negotiations. Though really, it’s a dubious victory if you have to do a bunch of last minute work right before an inspection to fix problems that had been around for months – doesn’t that just mean the union was right?

But, see, asphalt doesn’t last forever, especially if the underlying problems weren’t actually fixed (as a MOW commenter said, that kind of damage could be due to broken rail near the heel block of the switch, or waterlogged rotted ties underneath, neither of which are fixed by a fresh coat of asphalt). Check this audio from June 2013 about the same switches west of Lloyd Center, and here’s how that area looks as of this month. In other words, no, it hasn’t been fixed yet.

August1

August2

August3

Remember those yellow cones denote a slow order - that is, a reduction in speed through this area because going full speed through damaged track would be dangerous. So, as I said earlier, while it’s nice that the work for the Orange Line is coming along, I don’t think that’s really a valid reason to neglect maintenance on the existing alignment in the meantime. You know, safety being a value and all.

Call board safety video

From the “I forgot I had this” files (sometimes I have the memory of a goldfish). This is a short TriMet safety video about call boards and their use to protect workers in the right of way. Safety at rail is not a joke and it’s never taken lightly because of how severe the consequences of a lapse in safety can be. I think it’s a good thing for the public to see things like this because ordinarily they don’t get the opportunity to watch how much effort goes on “behind the scenes” to keep things running smoothly and safely.

Not your normal operating conditions

To date, most of what I’ve written about has been how things work under normal operating conditions because, well, that covers most of what people ask about since it’s what you encounter on a day-to-day basis (how fast do the trains go, what kind of signals do they use downtown, etc). But there are a lot of interesting things that go on outside of normal operations (e.g. manual blocks), and if you were riding the trains through the recent weekend maintenance work between Sunset and BTC or on the Yellow Line, you would’ve seen some unusual moves, wayside flags, and signal aspects.

For reference, these are wayside flags (here stored at the Elmonica yard)

If you missed it, it’s okay, other people went out and took pictures and are letting me use them, so thanks to them I’ve got some content for this post.

First off -

What was the maintenance work for, anyway?

As you may recall (and now that we’re heading into June, I expect this old entry to start getting more traffic if/when we get a heat wave), extreme heat conditions can adversely affect rail. In areas at risk for sun kink, which is a lateral slide in the rail caused by the rail buckling as it expands in the heat, slow orders (reductions in speed over a specified area) are issued.

10mph slow order in between BTC and Sunset

The expansion joints prevent this buckling by having gaps in the rail that give room for the rail to expand, thus absorbing the stress and force of the heat expansion. In order to put these expansion joints in, parts of the alignment had to be shut down.

So what does that involve?

Out of service, Yellow Line

When a track is out of service, double red wayside flags will be used – one in between the rails, one immediately next to them (also seen at Sunset on Pdxrailtransit’s blog). You do not proceed past double red flags for any reason.

Yellow/Red Wayside Flags

Double red flags will be preceded by yellow and red wayside flags like these. These indicate that a train will have to stop within 1000 feet. Here on Interstate, these were placed before the southbound platform at Lombard because trains were using the switches just north of the northbound platform to turn back.

Turnbacks

This train has already turned back and is now heading south on Interstate. Those of you with sharp eyes may have noticed a familiar signal in the last two pictures, with an unfamiliar aspect:

Yellow X on summary switch indicator 427

Time lock switch refresher time! These summary switch indicators on Interstate inform operators of the state of the time lock switches. Under normal operating conditions, these display a lunar which tells operators that the switches are aligned normal and are locked. Once the padlock for the switch has been removed, the summary switch indicator will display a yellow X, as shown above. For this work, operators stopped trains just past the 427 A and 427B switches, went back to what had been the trailing cab of their train, and crossed over to the southbound track to continue service southbound. Because the padlocks were off so that supervisors could throw the switches to enable trains to make this move, this summary switch indicator for the 427 switches displayed a yellow X.

Time lock switches were also used on the west side for turnbacks, as shown here at Beaverton Transit Center (also at Sunset for trains to go back east – sorry, no pics of those):

This series of pictures shows an eastbound train approaching BTC via the pocket track, which is normally the end of the line for westbound Red Line trains. This train is going to head west from BTC out of this same track, this time switching over to the westbound main. If you’re not very familiar with the layout here, it may help to see the overhead view – even though it takes a while to get a train through time lock switches, there’s not really any alternative to doing turnbacks from this side, and the time lock switches are still much faster than requiring trains to run reverse (which would involve restricted speed, no signal protection, use of island circuits to cross gated intersections, etc).

Similar to the first picture of the double red flags on the Yellow Line where you can see supervisors ready to throw the switches once the timer counts down, Pdxrailtransit got some pictures of supervisors at BTC who were on hand to throw these switches – remember that time lock switches are manual switches, not power switches, so they can’t be thrown from the cab of the train. Someone on the ground needs to manually throw the switch, and while operators can do it when necessary, it’s faster to have someone else taking care of it in planned situations like these.

So sure, some passengers were not happy with the additional travel delays, but for the people who like seeing some of the more unusual operations of the system, there were some nice examples of that over the last few weeks. Silver lining, right? And the expansion joints will make those areas safer in hot weather, so really this benefits everyone.

Hand signals

I’ve been looking at videos of the Shinkansen (the Japanese Bullet Train) on Youtube. I’ve never been to Japan, but if I ever get the opportunity to go, you can bet I will make it a point to ride the Shinkansen. More than once!

If you watch the videos, you’ll see the operator pointing at a lot of things. I think the pointing is fascinating – as best as I can tell, they’re trained to point at signals and speed signs. I wonder what the reasoning is behind that – to keep them from going on autopilot?  To ensure that they know where the signals and signs are? So that they can’t use “I didn’t see it” as an excuse if something happens?

It’d be interesting if they tried to implement something like this at TriMet.  I don’t think it’s necessary (we have the ATS magnets which will stop the train if an operator tries to go past an ABS signal that doesn’t have an indication to proceed). But it’s an interesting approach to staying alert – I know during training, new operators will be quizzed while operating (“What was the aspect of the signal you just passed? So what will the next signal be? Will there be another signal between you and the next platform?” etc) that help the students learn where to watch for signals on the alignment, and some students will continue to talk through those locations as they learn. But beyond that, there’s nothing like the pointing at signs or signals like the Shinkansen operators do.

MAX Hand Signals

MAX light rail hand signalsKind of looks like instructions for a line dance arranged this way.  Try this at the next wedding you go to.

MAX operators follow hand signals, but unlike the Shinkansen operators, don’t really give them while operating (and a friendly wave to the operators of trains or buses you pass doesn’t count).  Rail hand signals are one of the first things that operators are trained to do – by the end of day one we could all demonstrate & understand the hand signals for stop, stop at a particular spot, proceed, reduce speed, proceed AT a reduced speed, and back up.  And we learned how to acknowledge those signals from inside the train to let the signaler know we understood.  For the most part as a passenger, you probably won’t notice anyone giving hand signals to the train that you’re on, though sometimes you’ll be able to see workers in the right of way giving a proceed sign (“while facing the operator, raise and lower the arm vertically alongside the body”) to a train.

One of my first experiences with hand signals outside of the classroom (not counting workers in the right of way telling me to proceed) was on my last trip of my last day of line training – Control called my train to inform me that there had just been a car accident not far past a few platforms ahead of where I was. A car had crossed into the right of way and was stuck inches from the westbound track, and I was going to be the first westbound train through there, so I had to call Control for further instructions before leaving the platform closest to the accident.  My line trainer said he was comfortable letting me handle this if I wanted but he’d take over if I didn’t feel up to it.  I told him I wanted to do it, so when I got to that platform (and called Control telling them that I was there!), I left at walking speed and stopped where a supervisor on the ground told me to. Then I proceeded very slowly on his signal, reducing my speed even further as directed via hand signals while another supervisor checked alongside my train by the car to make sure there was clearance for me to keep going. There was *just* enough room for my train to pass without making contact with the car at that slow speed – the natural sideways sway of the train at full speed would’ve probably hit the car.

I had been running several minutes late (due to a mistake on my part when I had been westbound at Rose Quarter, I timed my calling my signal wrong and it timed out back to a red before I got my doors closed) and I was far too new to be able to make up for that lost time and get back on schedule – in fact I think I fell even further behind schedule. In retrospect I’m glad I was late, because if I was on time, that car might’ve crashed into me had I been going through that part of the alignment at the full speed.

Upcoming posts – more in-depth descriptions of the train cars, the overhead catenary systems, and a list of questions from one of the readers here.  So that should keep me busy for a while!

HEAT WAVE. (and MAX hot weather operations)

Question: Why do the MAX trains go slower when it’s hot out?

I’ve been waiting months to make this post.  Not kidding – I know this question comes up every year when Portland gets a heat wave, so in February I took this picture:

Weighted catenary, February 2010

The temperature that day was somewhere in the 50°s – notice how far down on the pole the weights are hanging.

And compare the weights to this picture, same location, yesterday when it was about 88°F:

Weighted catenary system July

Edit evening of 07-08-10:

Here’s a picture from earlier today when it was about 100°F.

Weighted catenary at about 100 FYou can see that the weights are down a few inches from where they were at 88°F, and much farther down from where they were in February

I asked one of the MOW guys to explain how this works to me a while back. The pantograph on the top of the train is spring-loaded to push upward on the overhead wire, so the wires need to maintain tension. Tension in the overhead catenary wires in the high-speed areas of the alignment is kept in balance by weights like these – as warm weather makes everything expand, the weights drop further down to maintain tension in the overhead and keep it from sagging. But there comes a point where the weights hit bottom in extreme temperatures. When that happens, any additional expansion from the heat will make the catenary wires sag since the weights can’t drop any further to provide tension. So the trains run slower to avoid damage to the pantograph (and overhead wire) since the overhead wire has gone slack and can no longer provide the necessary resistance against the pantograph. Trains will drop their speeds by about 10 mph in high-speed areas when it gets to be above 90°F, and drop the speeds even more when it goes above 100°F. Plan accordingly if you will be traveling by MAX train!

Sun kink is another concern in extremely hot weather.  I have no TriMet pictures of sun kink, so here is one shamelessly borrowed from the Iowa DOT:

Sun KinkSun kink in rails

I’m no physicist so I’m not going to attempt to explain the nitty-gritty science behind it. But basically the ballast & railroad ties can keep the rail in place with normal heat expansion and contraction. However, with extreme heat, the construction of the rail can’t handle the force of expansion, causing the rails to slide laterally. There is especially high risk of this happening with big temperature swings (very hot during the day, cool at night), so during the summer it’s not uncommon for there to be slow orders for trains in areas of the alignment at risk of sun kink.

Slow OrderOld pic – I don’t remember why this flag was out, but here’s a picture of a wayside flag designating a slow order – a train must be at the speed limit posted on the yellow slow order flag when the front of the train reaches the flag, and then proceed no faster than that limit until it passes a green wayside flag.

You may also remember earlier this year when expansion joints were installed in areas of the rail on the west side and on Interstate where sun kinks are likely to develop. These joints give the rails room to expand to reduce the likelihood of the rail buckling.

104 in busTemperature in one operator’s unairconditioned bus

And my own PSA/editorializing during the heat wave – be nice to your operators! You can get off of the 100°F+ bus when you get to your destination – they’re stuck on it for their whole shift! (and even the air conditioned buses and train cabs can get the whole greenhouse effect going on too – this is not the nicest time of the year to be a transit operator! I mean, they tell you on the news not to leave your kids or pets in a car even with the windows opened because the internal temperatures can top 100°F – what about your bus passengers & operators?)