Tag Archives: type 2

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


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.

Car 235, how are you?

Not that I’m the kind of person to anthropomorphize the MAX cars, but if I did I would totally pity car 235, who’s like the poor guy that always happens to be in the wrong place at the wrong time.

If you’ve seen it around, you may have noticed that 235 looks a little different from the rest of the Type 2s..  the others all have either the old paint scheme:


Or full-body ads:


235 is a little different – it could almost pass for a type 3 as it’s the only 2 that’s rocking the new TriMet blue and yellow color scheme that all of the type 3s are painted in (though one side of it has had an ad for a while), and the mirrors are still those of a type 2.

235 and some other Type 2

235 on the Yellow Line downtown

It wasn’t always like this.

Don’t remember where I found this, but this is an old shot of 235, looking like all the other Type 2s

But then, one day in 2005, 235 had a tangle with a fire truck in Hillsboro. It sustained severe damage in that crash.

Not my pics, I don’t have bigger versions of them

235 was repaired and re-entered service. As far as I know, it had a relatively uneventful life after that, until a few years later, when it was the trailing car of the train that derailed at 11th Ave.

Well at least it wasn’t the lead car?

Just along for the ride, so to speak

And then yesterday, a semi-truck loaded with cars crashed into 235 at 10th and Washington in Hillsboro. I’ve heard the operator is ok. It also was not his fault, which is also good news, and as far as I know the damage to 235 wasn’t too bad, aside from the windshield.

Pictures courtesy of Hillsboro Fire & Rescue

But we can rebuild it. We have the technology.

MAX-eye view

I haven’t posted any video in a while, so here you go. Eastbound from 1st and Morrison to the Rose Quarter, filmed a few years ago.

Anatomy of a MAX car, Part 2

Train Car Anatomy, continued.

Coupler head

bullnoseThis is a Type 2, but the setup looks more or less the same on the Type 1s (and the coupler heads that fit these are folded under the cab of the Type 4s).  Under here you can see the bell, and then at the bottom going horizontally across the tracks is a bumper that prevents something that the train hits from going further under the train. The coupler head (bullnose) is at the end of a deformation tube which allows a coupled train to bend around curves and is collapsible in case of a collision.

deformation tube bendThis should’ve been straightened out as part of the ground inspection, but if for whatever reason this car needs to be coupled at this end, an alignment check is part of the coupling process that’s done to ensure that the deformation tube is straight


CyclopsEastbound approaching the Fair Complex as a westbound train is leaving.
Bonus – rainbow!

The cyclops, sometimes called the railroad light serves two purposes.  One, helps the operator to see in the dark. Two, clearly identifies you as a train! A foot pedal inside the cab lets the operator turn the cyclops off – this is used at night when passing other trains (or buses on the Steel Bridge) the same way you turn your bright headlights off when passing other cars on the road so you don’t blind oncoming drivers. Many operators will also kill the cyclops when they’re stopped at a platform at night so that in the event a train passes through in the other direction, their light is already off.


anticlimber, type 2

I’ve never seen one of these in action, nor do I particularly want to…  in the event of a train-train collision, the anti-climbers theoretically lock together and prevent one train car from climbing the other. The type 4s have these too, but they’re hidden underneath the shell that covers the coupler head. A combination of the ATS magnets, rail operator attentiveness and skill, and good direction from rail control is what prevents these accidents from happening in the first place (and therefore no need to test the integrity of the anticlimbers on our own any more than you want to test the integrity of your car’s airbags on your own)

And let’s take a look at the bottom of the train:

This is from a couple of years ago when a train derailed downtown – ordinarily you won’t see the wheels on a MAX car like this – they’re covered with a panel called a skirt. But the skirts were taken off this train in order to get it back on the rails, so now you can get a nice look at the wheel trucks.  That rectangular thing between the wheels (that in this picture is pressed against the ground) is the track brake. This heavy magnetic brake normally hangs just above the rail.  When the operator uses it, it makes a sort of clunking sound as it drops and a beep that you’ll hear if you’re sitting up by the cab, and it quickly slows the train down, stopping the train if the brake is continuously applied. It’s often used coming into platforms on slippery track surfaces such as leaves, ice, or water to stop the train. And of course, the wheels are found here.

In that above picture, the sanding tube is visible (it’s sort of visible in the first picture in this post of the coupler head just behind the bumper, though on the Type 2s and 3s it looks more triangular). You’ve probably seen the sandboxes on the trains even if you never thought much about them. I’ve been asked a few times what those are for.

Sand boxes in a Type 2 under the seats

Sand is automatically deployed to give the train better traction – it makes a sort of buzzing sound. You’ll notice this when the rails are wet, especially when trying to pick up speed going up a hill (e.g. entering the tunnel westbound from Goose Hollow).

track brake, wheels, sanding tubeWheels, track brake, sanding tube (visible on right)

Maybe I’ll add more to this anatomy… maybe not..  there are a few things I didn’t get into but it’s getting harder to find the time to blog these days and there are a lot of other things I want to write about.

Anatomy of a MAX car, Part 1

And now.. a reference post describing a train car in detail, so if I refer to any part of it by its name in another post, you’ll know what I’m talking about.

Type 1, 2, and 3:

The cars are symmetrical, so it wouldn’t be helpful to describe them by “front end” or “back end” – so instead there is the A-end and B-end.  C is the section in the middle, because we enjoy being difficult like that.

A-end of 326

A cab of 326

B-end of 326

B cab of 326

Same car, different ends

Type 4s:

Not symmetrical since there is only one cab per car.  So the cab is always the A-end, and the parlor area where passengers can sit is always the B-end.

Car 412 A-EndCar 412 A-End

Car 420 B-endCar 420 B-end

On top of the train is the pantograph. In the Type 1s, 2s, and 3s, the elbow of the pantograph points towards the B cab and the open part points towards the A cab – it’s the quickest way to tell when you’re outside the car which end is A and which end is B, which is necessary for some troubleshooting procedures.

Car 304Car 304, coupled at its A end

Type 4Pantograph on the Type 4 – notice how it points to the cab, which is the A end

In the Type 4s, that’s reversed – the open part of the pan points to the B-end and the elbow points to the A-end, because as I said, we enjoy being difficult. But it’s always easier to tell which end of the 4 is A and which is B, since only A has a cab.

Doors and Bridgeplates

Type 2 with bridgeplates outType 2 with doors open and bridgeplates deployed

Every door in a train car is numbered from 1 to 8, with door 1 being the first door on the left facing the A cab and door 8 being the last door on the right.  On the right side (facing the A cab), doors 4 and 6 on the low-floor cars (Type 2, 3, and 4) are bridgeplate doors, and on the left, doors 3 and 5 are bridgeplate doors.  The bridgeplate is the ramp that can be deployed to assist passengers in wheelchairs or other mobility devices in boarding and exiting the train.

Emergency intercoms

The passenger emergency intercoms are push-to-talk intercoms used if there is an emergency on board the train.

Good things to use this button for – alerting the operator if a passenger has a medical emergency, if something happens that requires police involvement, smelling something burning onboard the train, spotting something that looks like it could be a mechanical failure on the train, etc.

Bad things to use this button for – a shiny thing for your toddler to press, as a means of asking the operator what time it is or if this train goes downtown, or as a means of asking the operator for advice on your romantic life. Yes, that has happened.

Type 1 IntercomIn the Type 1s, you can find the emergency intercoms to contact the operator by looking above the seat located to the left of the cabs.

Low-floor intercomIn the Type 2s and 3s, the intercoms are located near doors 3, 4, 5, and 6.

In the Type 4s, there are intercoms at doors 1, 4, 5, and 8.

Reader boards

The reader boards are the displays in the train that show the name of the next stop (connected to the APACU, which is the automated audio/readerboard announcement system, and maybe I’ll give that its own entry in the future)

Readerboard, Type 2Type 2/3 Reader board

Readerboard on a Type 4Type 4 Reader board

Type 1s have no readerboards.

If the readerboards are dark or aren’t showing the right stop, let the operator know – it’s not always obvious from the cab if the readerboards aren’t working right.

More to come..