I lied – More signals!

Okay, I forgot two.

Dwarf Signals

Ruby Jct/E 197th, looking eastDwarf signal in lower left corner

I love this picture because there’s so much going on in it.  Ruby Jct/E 197th looking east, zoomed in (I took the picture from the westbound platform) so the quality is a little grainy and the distance is flattened out – objects in the picture are much farther away than they appear!

I forgot the dwarf signals because under normal operating conditions, you don’t really see them because they don’t face you. Dwarf signals for MAX are only used when running reverse – notice how in the above picture which is facing east, the dwarf signal is on the westbound track, so you’re only going to see it if you’re going east in the westbound.

Anyway, the purpose of dwarf signals are to protect power switches on the mainline when you’re running reverse in ABS territory. They won’t display any aspect other than red, though some will go dark if there’s no train in the circuit. They’ll be associated with ATS magnets and switches.  When running reverse without signal protection, you must stop at all switches to make sure they are properly set since you’ll be coming at them from the wrong direction.

Dwarf signal at BTC“Dwarf” not always short

Here’s dwarf signal W768 and two standard ABS signals at Beaverton Transit Center looking east.  They’re all the same height, but the dwarf is the only one that can only display a red aspect.  In this picture it’s dark because there’s no train in the circuit.

Same signal, now with a train in the circuit (in the westbound platform)

That particular signal protects the switches that Red Line trains take into the center pocket track at Beaverton Transit Center – which are located pretty far around that curve, so dwarf signals aren’t always right on top of associated switches.

The C Signal

For lack of a better name, anyway.


There’s only one of these that’s still in use, and it’s at Skidmore Fountain westbound (there is also one at 11th & Yamhill, but it is not active). The intersection after this platform is SW Ash, but you can’t see it from here, so when an operator selects at Skidmore westbound, the “C” signal illuminates to let them know that the call went through and they can leave the platform.  When they get to Ash, they should have their pre-empt.

Next up – not sure yet, but it won’t be signals!

11 responses to “I lied – More signals!

  1. nope not gonna do it

    For bonus points, there is a second “C” somewhere. Pay close attention over your right shoulder the next time you travel EB down Yamhill around the 11th Avenue Terminus. For extra bonus points, name the one other location (long since removed) where one of these signals was located.

    • Hmm.. I would’ve guessed Library/9th as the one that had been removed? I kind of remember being taught that, though I also remember learning to watch the traffic signals at Broadway when leaving that platform.

  2. nope not gonna do it

    Yup, Library had a “C” signal to prime the signals down at Broadway for a move eastward. The “C” from 11th Avenue Terminus is still (or was the last time I was down there) hanging, but no longer in use. It can be seen against the backdrop of the parking garage on the SW corner of 11th & Yamhill.

  3. I don’t remember the signal number, but I think there is a dwarf signal running reverse on the eastbound track just east of SW 117th by Beaverton TC. Whenever I pass it while on a westbound train, it is always red. Can you clarify for me what the purpose of this signal is, and when it would be used?

    • Sure – that’d be dwarf signal W712. Dwarf signals are associated with power switches in the mainline, and this one protects the switches that would get a train into/out of the pocket track at BTC from the east if running reverse.

      Here’s the overhead view of those switches – the eastbound track is the bottom one. All of those switches are power switches, but there’s no call loop for them coming at them from the east in the eastbound main. So assume for example that a train is west in the eastbound. If they don’t stop, the first switch they encounter will either send them straight on the eastbound main or diverge them to the pocket track – however, if that next set of switches is set against them, the train would derail as that’s a trailing move. The dwarf signal forces a train to stop prior to the switches, though when running reverse you have to stop at all switches to observe that they’re set properly so for safety a train would stop twice here.

  4. I get it now! Thank you. One more question about the signals in that area: Is the secondary aspect on the eastbound signal out of Sunset TC to access the auxiliary track just west of the tunnel and/or run reverse down the westbound tunnel, in the same way that the signals westbound out of Goose Hollow do headed westbound on either track?

    • Yes, a yellow over green on W544 eastbound at Sunset will send you into the west portal pocket track (but via the eastbound main, that signal is not for the crossover switches immediately east of the platform since those are time lock switches so you won’t be running reverse from that signal). Then once you get to the west portal pocket you use a different route code to run east in the westbound bore.

  5. That makes sense. The link to the time lock switches helped a lot too.

    I’m an avid rider and learner of all things TriMet, and have found your site the most insightful and awesome, alongside Jason’s rosecitytransit.org. If I have more questions (which I’m sure I will), what is the best method to submit them?

    • Thank you, I really appreciate that.

      I try to avoid having any “official” channel to ask questions through… I’ve been asked that before, and my response basically is that although I like talking about the trains with people and don’t mind answering questions, I can’t do it in any official capacity since I am not a TriMet spokesperson. I don’t feel comfortable with telling people to direct their rail questions to me because I can’t be acknowledged as someone who has the authority to claim an answer is correct and official TriMet information. That’s not to say that what I post is inaccurate, but I don’t feel right making it appear like I am a resource for official TriMet information online.

      So if you find a related post feel free to tack a question on like you’ve been doing, but I don’t have any plans to put up a “contact me” form or anything like that.

  6. I understand. Thank you for making your knowledge available for us still.

    • You’re welcome! When I started doing this I didn’t expect so many railfans to end up here (what really tipped the scales for me was one too many complaints about the yellow door buttons so I wanted to do my own outreach where TriMet – officially speaking – wasn’t). It’s been an interesting ride!

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