Tag Archives: weather

10 secrets, tips and tricks for cold-weather TriMet riders

type IV


Editor’s note:
 Guest post time again, this one via Michael Andersen of Portland Afoot, PDX’s 10-minute newsmagazine about buses, bikes & low-car life. It’s excerpted from the January 2012 cover story and republished here in case you missed it. For more stories like these or to get a one-time email notice when the newsmagazine for Portland transit riders will be available for free on mobile devices this spring, visit PortlandAfoot.org.

Rain? No sweat. But let’s confess: Portlanders don’t do cold well.

That’s why, last year, our 10-minute newsmagazine for transit riders put some of the smartest folks in town (including TriMet’s professional comfort geeks) in the hot seat and came away with a bunch of tips and secrets for doing winter better.

As a longtime MAXFAQs fan, I was proud to be asked to republish the transit-oriented ones here, and happy to help take the chill off the tail end of this winter. So read these, wipe that drippy nose and go catch some sun.

- Michael

Slim Jim stylus

slim jim color

Smartphone styluses start at $13, touchscreen-friendly gloves at $14. Beef jerky sticks, by contrast, are $1.30, and they work just as well when you want to check arrival times with gloves on. Try it.

In with the old

There’s an easy formula for temperature control on TriMet’s old high-floor Type 1 MAX cars, says TriMet rail equipment manager Mark Grove: “Stay away from the doors.”

Pressure heater

doors

MAX doors don’t actually matter nearly as much as they might. Here’s why: TriMet keeps air pressure inside its trains just a bit higher than Portland’s natural atmospheric PSI. That means opening doors send a burst of controlled air out – not a burst of cold air in.

Dead simple

Type 1 MAX cars have overhead forced-air heating and cooling powered by the same electricity that moves the train (it’s maybe 2% of the total system load). Two thermostats in the return air ducts, on the ceiling just behind each driver cab, aim for a Jimmy-Carter-approved 68 degrees year-round.

Winter radiance

max heater

Like movie franchises, Decemberists albums and mediocre dates, the four generations of MAX cars peaked with the second and third. In 1997, TriMet introduced one of the great joys of Portland winters by rolling out Type 2 MAX trains with floor-level radiators that kick on whenever outside tempeature drops below 55 and inside temperature below 66. On the coldest days, avoid the middle sections of Type 2, 3 and 4 cars – their facing seats still lack heaters underneath.

Everything’s relative

hvacandmore

Starting with Type 3 in 2003, new MAX cars have used an advanced thermostat in their overhead heaters that automatically varies the target inside temperature based on outside temperature. When outside temperature is below 60, the target inside temperature is 66, gradually scaling up to a max of 72 when outside temperature exceeds 72. That means less sweat when you’re in long johns and fewer goose bumps when you’re in shorts.

Backseat oven

Like other autos, TriMet buses get all the heat they need from their engines. This one pumps heat forward through a duct system above the handrails, but the back rows of the bus are always hottest, thanks to heat leakage, less crosswind and (on the new, low-floor buses) being closer to the ceiling.

Electric blessing

left-side heater

Cold feet? Try the seat immediately in front of the rear door on newer buses, and the one opposite the rear door on the very newest ones. Most of the buses without these small heaters were phased out last summer with TriMet’s big bus purchase.

Low-tech thermostat

bus thermometer

All TriMet buses are theoretically set at 72 degrees, but at their size it’s hard to keep to. Bus thermostats are tested in off-hours by a six-inch hand thermometer hung from the extreme front of the right handrail.

Platform warmth

type ii

Here’s a science-approved trick to use while waiting for winter trains: Play a game on your phone. In a 2011 study, a team led by Nicola Swain-Campbell of the University of Otago in New Zealand found that people playing a video game were less sensitive to cold water than people watching television. But gamers should hope the battery lasts until the bus arrives. “If they stop while still cold, it might seem more intense as all their attention switches to the sensation of cold they have been ignoring,” Swain-Campbell said.

Nothing to do then but eat your Slim Jim.

 

MAX coupling

Not dead. Just resting.

Coupling Info and FAQs

This is going more in-depth on an old anatomy post where couplers were mentioned. The coupler at the end of each MAX car (with the exception of the A-end of a Type 4) allow for both a mechanical couple and an electrical couple between cars. The mechanical couple is what physically keeps the cars connected, and the electrical couple is what allows the cars to communicate. By design, both a mechanical and electrical couple need to be established in order for the train to move.

Although the Type 1s, 2s, and 3s are capable of being coupled into consists longer than two cars, MAX trains do not run in longer consists longer than that. There are rare exceptions to this (e.g. getting a disabled train out of the way), and yes, some 20 years ago trains were brought back into the Ruby Yard in longer consists but the length of city blocks downtown and the subsequent design of all the train platforms limit the length of MAX trains to two cars.

Note: There are several categories of TriMet employees who are qualified to couple and uncouple cars (operators, supervisors, mechanics, etc) but for simplicity I’m just going to go with “operator” in this post.

The Electrical Couple

The coupling process won’t make much sense without describing this first. At the top of the coupler is the electrical coupler head. Under normal conditions, this is either coupled to another train or covered, but occasionally one with the cover up will sneak through ground inspection without being noticed (or alternatively the operator will forget to switch it back after uncoupling cars).

Electrical coupler head on a Type 2 with the cover raised

There are two positions for the electrical coupler head – electronically isolated and electronically normal. If one or both electrical heads between coupled cars are in the isolate position, there will be no electric communication between the cars. When coupling cars, the first goal is to establish a good mechanical couple, and to do that the car doing the couple will be electronically isolated at the beginning of the process.

This switch inside the cab controls the electric coupling of the train

Coupling cars

First, as with just about everything else done with the trains, the operator will get permission from Control before coupling. Next, they’ll do a ground inspection of the car they will be coupling to in order to ensure there aren’t any safety concerns, such as personnel working on or around the car. They will also make sure that the car they are going to couple to is set to electronically normal. The operator will make three safety stops in the coupling process (because hey, you’re essentially about to drive one train into another train) – the first one car length away from the car being coupled to; the second about 10 feet away, and the third at about 3 feet away to ensure that the couplers of both cars are aligned. Then very slowly, the operator will bring their car forward and couple mechanically to the other car (this happens automatically).

The operator will then perform what’s called a “tug test.” As mentioned in the last section, the car that the operator is in is electronically isolated. When there is no electrical communication between the trains, the brakes will apply. In a tug test, the operator remains in the coupled cab and attempts to put the train in reverse and move. The test is a success if the cars do not move – this shows that the mechanical couple was correctly done because it’s holding the operator’s car (which should otherwise be moving backward) to the car with the brakes applied. If the operator’s train car moves backward, it’s either because the mechanical couple failed and the cars came apart, or the cars were not electrically isolated. A visual inspection of the couplers will also be done.

Next is the “trainline test” which is also done from the coupled cab. The operator will now set the car they are in electrically normal (remember that the car they coupled to is also electrically normal). Now there should be communication between the cars, and the easiest way to test this is to open and close the doors. In the yard, this will be done on both sides of the train, and the operator will watch to see that the doors in both cars open. On the mainline, this will only be done on the doors that are on the platform side for safety reasons. If the trainline test is successful, the coupled cars are ready to go.

The finished product: Two successfully coupled train cars. Note how the electrical coupler heads are raised and the covers are on top of the coupler. When the cars are separate, those will slide down over the electrical head.

Uncoupling Cars

A simpler process – again, always done with permission from Control. The operator will do a safety inspection and then press the “uncouple” button in the coupled cab (pictured in the first section of this post, it has a cover over it to prevent it from accidentally being pressed). Next the operator will back their car from the other one to separate the mechanical couple.

Mainline uncoupling

Uncoupling on the mainline is not preferable, but is sometimes necessary in order to cut a bad car and leave a “sportscar” train in service. The exception to this is, of course, the Type 4s, because they can only be fully operated from one end so they can’t be uncoupled on the mainline.

And then the 4s

The coupling and uncoupling processes above apply to the Type 1s, 2s, and 3s. The 4s are more complicated – as you can see in the above picture, they don’t match the coupler heads of the rest of the fleet. Under each Type 4 cab (the A-end) is  a fold-out mechanical coupler head which can be used to mechanically couple a 4 to any other car to be towed or pushed. Type 4s can’t be electrically coupled to the other types of cars, and are the only cars that have the step of connecting the canon plugs of the cables on either side of the mechanical coupler head to electrically couple.

Mechanical coupler head under the A-cab of a Type 4

COUPLER FAQS:

What’s that bag over the coupler head? (seasonal)

These covers basically work like shower caps and are put over the coupler heads in snow/ice conditions to prevent ice from building up on the couplers. Metal covers used to be used but I don’t remember how long it’s been since they were.

Why is a coupler off-center?

deformation tube bend

The coupler heads are designed to be able to bend around curves in the alignment, so if you see a coupler like this, it isn’t broken. They should be straightened out during a ground inspection, but sometimes one gets missed. The operator or a supervisor will move it back into place when they see it.

What happens if the train cars come apart?

If that were to happen, they stop – the default position for a train car is “stopped” and the loss of electrical communication will apply the brakes in the trailing car, much like how the tug test works. I’ve heard some people are not comfortable riding in the trailing car due to “runaway train” fears if the cars separate, but the purpose of the tests done after coupling is to ensure that that doesn’t happen, so this isn’t something passengers need to worry about.

Today I learned: The more you write the word “coupler,” the weirder it looks.

Of ice and electricity

Photo of what winter weather may look like, westbound at Hawthorn Farm

Steven Vance recently forwarded me a question about why CTA‘s rails have been sparking. Unlike MAX trains which get power from an overhead wire system, their trains get power through a third rail system. However, arcing in both kinds of power systems during winter weather is typically caused by ice. Ice building up on the wire (or third rail as the case may be) acts as an electrical insulator, preventing the carbon shoe from making contact with the wire where the ice accumulates. This interruption in the flow of the current from the wire to the pantograph is visible as arcing.

Here’s a video of a MAX train pulling into & out of a platform where there was some ice on the catenary, and you can easily see the effect that it has:

To help clear ice from the overhead wire & prevent it from accumulating, a few of the Type 1s (107-112) are equipped with ice cutters which are put into use for major freezing rain/ice events. I don’t have a picture of any of them in use (though I’m willing to accept donations!), but they look like a second pantograph and function by heating/scraping ice from the overhead wire. Unlike the pantographs, ice cutters only draw current to heat the elements and not to provide power to the train, so they won’t arc the same way the pantographs do in ice. Their function is strictly to clear ice from the wire.

Pantograph (left) raised, ice cutter (right) lowered

If you’d ever seen one of these cars and wondered why it has two pantographs, wonder no more! It doesn’t – one pantograph, one ice cutter.

View from above; the ice cutter is the one closer to the coupled end, the pantograph is the one in contact with the wire closer to the vantage point. Bonus cameo appearance by car 235

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.

HVAC

Still working on the improving transit speed follow-up post, which is getting very long and I need to either break it down into separate posts or stop being so long-winded. In either case, it’s not ready to be published yet, so here’s a quick and easy post.

Question(s): Can’t you turn the heat down? Or up? Can you turn the air conditioning off, it’s too cold in here!

Answer: Sorry, no. There’s not exactly a thermostat in the trains… let me show you what there is to work with:

 Part of the upper console of a Type 2

This one gets asked fairly frequently, especially in the spring and fall when the temperature outside fluctuates so widely. The HVAC (heating, ventilation, and air conditioning) system in the train turns on when the operator turns on the train’s auxiliaries (done when starting up a train to take it out of the yard) and should automatically adjust to the temperature outside. As shown in the above picture, the HVAC switch all the way over to the right lets the operator turn the HVAC off but that’s all. There are no adjustments for temperature like your car has.  You can’t even turn the HVAC back on with that switch – notice how there’s no “on” side. Once the HVAC system is off, the only way to turn it back on is by auxing the train off (the switch next to it) and auxing the train back on. This is generally only done as part of troubleshooting if the HVAC system has a fault and needs to be reset. So no, there’s not a lot that can be done with the heat or A/C for the train passengers short of simply having them on.