For reader Matt, who had asked about signals at Rose Quarter some 6 months ago and I’m finally writing about it. In other words, it’s a good thing “Professional Blogger / Fielder of Questions” isn’t what TriMet hired me to do.
The Rose Quarter interlocking is very complex (I’ve heard it’s one of the most complex in the country, but I don’t really have much of a basis for comparison). I’d wager it’s probably also one of the busiest, with trains passing through every few minutes. The complexity of this interlocking’s design allows for a lot of flexibility for trains in the event of a bridge lift or other reroutes.
For simplicity, in this post RQ refers to the Rose Quarter platform used by Blue, Red, and Green Line trains. IRQ refers to the Interstate Rose Quarter platform used by Yellow Line trains.
First, the whole thing from above:
Rose Quarter Platform
Starting with the signals associated with the Rose Quarter platform.
Coming into Rose Quarter from the east (Oregon Convention Center platform), the first signals you encounter are 18A and 18B. 18A protects switches 13A, 11C, and 11D, and will remain red with an active ATS magnet if any of those switches are not aligned to move west or if there is a conflicting move in progress (e.g. a vintage trolley coming in or out of the trolley barn). 18B gives you a choice of routes between the special events track which is the middle platform, the westbound mainline track which is located to the right of the special events track, or the trolley barn.
Now in the RQ platform, looking westbound first:
16B and 16C can display identical aspects for identical routes (remember, it’s not where you are, it’s where you’re going) – the only difference is that 16B is for trains heading west from the special events track and 16C is for trains in the westbound main. A white vertical will send you toward the Steel Bridge; a red over white vertical will send you toward IRQ (Yellow Line). These signals will stay red if the bridge span is unlocked for a lift, or if there is a conflicting move in progress with the Yellow Line.
And then east from Rose Quarter:
18E and 18F (similar to 16B and 16C) can display identical aspects for identical routes, with 18E used by trains in the westbound main and 18F used by trains in the special events track. A white vertical will send trains east on the eastbound mainline; a red over white vertical will send trains east on the westbound mainline.
18G is the signal for eastbound trains in the eastbound mainline at RQ – no choice of routes available here. Memory trick for memorizing signal numbers (though I don’t think they do that anymore in rail training) – “G” for Gresham, and signal 18G will get you there.
Then away from the Rose Quarter platform itself…
Interstate Rose Quarter Platform
16E at the IRQ platform. A white vertical on 16E will send Yellow Line trains over the Steel Bridge; a red over white vertical will send them into Rose Quarter. This is how Yellow Line trains can get from Expo to the Ruby yard at the end of the day. Also, when a Yellow Line train operator forgets to change the route code in their trailing cab from Clackamas’s 12 to Jackson’s 50, they get a red over white vertical here.
Then at the other end of IRQ are N2A (for trains heading north from the southbound track) and N2B (for trains heading north from the northbound track) – like Rose Quarter, IRQ is also set up to allow turnbacks in the event of a bridge lift. A lunar on these signals will send trains on the northbound mainline; a red over lunar into the Broadway Siding – you may have been on a train in the morning where it stops at IRQ, kicks everyone off, but then appears to continue north. It only goes as far as the Broadway Siding before turning around and going back west over the Steel Bridge. (Linked video was not filmed, narrated, or posted by me and does not feature me. Linked video is also old, Train 6 hasn’t done that for a while, but 33 does it currently)
Coming off the Steel Bridge
Assorted pics of and through the interlocking
I also have this video which I’d originally posted a few months ago, showing a view from the cab from 1st and Morrison to Rose Quarter. This was a Red Line train, so we got a lunar on 16G and went through the interlocking at the same time as another Red Line Train.
Given the design of Rose Quarter, what’s ideal for train movement are parallel moves, where trains can move in opposite directions at the same time. Scheduling trains to do this reduces the need to wait for other trains (e.g. sitting at RQ waiting because a Yellow Line is going through, so the switches are set against you) as well as reducing the impact that trains moving through the intersection has on auto/bike/pedestrian traffic.