I am trying to scratchbuild dwarf signals based on photos I have seen in Warren W. Wing's "Northwest Rail Pictorial". They were located at Tacoma Union station in the late 1940s, probably governing train movement out of the passenger yard to the mainline, used by NP, GN and UP. The dwarf signals have two lights, but as all pictures are black and white I can not see if they are Red over Green (which I assume) or Green over Red Which one is more likely? Thanks a lot from a confused German (some would say not difficult to achieve...) Cheers Dirk
Red over Green....Medium Clear. Medium speed through turnouts, crossovers, sidings, and over power operated switches, then proceed. Green over Red....Slow Clear. Slow Speed through turnouts,crossovers, sidings, and over power operated switches, then proceed.
There are other indications also, flashing green or red lights, which are seen occasionally but if you just want something to get a train out of the siding, either of the first will work.
Jerry, do you mean that each dwarf lamp can have both red and green lenses, selectable by the yard traffic controller/dispatcher? That is, you might see red/red, green/green, red/green, and green/red, with either/both flashing depending on conditions?
I would be willing to bet if they are single color lenses, the colors are yellow on top and red on the bottom. If they are searchlight type heads, then the top would give green, yellow or red, and the bottom yellow or red.
I think he means the signal has one head and only one of the two lights is on at a time. The question is whether the green (or perhaps yellow) bulb is on top or bottom. That's something up to the railroad or the signal manufacturer. For dwarfs I suspect there may be some consideration for snow accumulation, although I haven't been able to study any dwarfs recently. On mast signals, I've seen it done both ways. For instance, on the NS line through my town, the older westbound signal has red on top, while the new eastbound main and siding signals have green on top.
Predominately, aren't most signals set up for red on top? All the ones around the Seattle/Tacoma area I've seen for the last 20 odd years are that way.
Signals On the Union Pacific and the BNSF where there are two or three lenses the red is on the bottom and the green on top with yellow in the centre. A signal aspect on a two headed signal of red over green would indicate the main occupied and the siding clear. Union Station in Portland had two lense dwarf signals and the red was on the bottom
Many thanks for all the feedback. It appears that there is no hard rule, unlike for a traffic light. My plan is to use the dwarfs to indicate if there is a viable route through a PECO c55 double-slip switch. It is soemtimes hard to see if the turnout is correctly thrown, so the dwarfs should give some indication if it is OK to proceed. My original plan was to use a single green light for "Go", a red for "Stop". But it appears that using a red light means stop, red over green "medium proceed" would be slightly more typical? Kurt indicated "Red over Green" in Tacoma and Seattle, so this is what I will go for. I am not willing to explore bi-color SMD LED (yet!), so I want to keep the dwarfs somewhat simple. Cheers Dirk Red over Green
