I’m planning to build a small layout based on US prototype at about 1960.
Google didn’t help me to get any information about the signals and procedures used within the yard.
e.g. How is the switcher controlled not to cross main line tracks if an incomeing train is expected? How does the switcher get the “go” to move to another track with some cars on the hook?
The question is twofold
What are basics of train and shut control within yards?
What kind of signals are used and where are they positioned?
Generally speaking there was an interlocking tower which controlled throwouts from a remote location. Some yards used ground throws with drawf lighting and the likes, Others used signal stands. Yard throws tended to be on the outside of the ladder if at all possible. (Crossing track in a yard by foot to throw a turnout was a task not liked my many RR personel because of the dangers of such.) If you are short of room however, a compound yard may be your only option. (This had throws inside the yard ladder)
For your model you might want to consider a Tortoise turnout motor. These turnout motors provide wiring terminals for turnout signals.
Communication was obviously done with the yardmaster in the yard tower that controlled everything. The sometimes had loudspeakers in the yard that had directions spoken over them from the yard tower. How often this was used however or where is beyond my knowlege.
Block occupancy detectors will tell you if a track is occupied or not by use of a signal. Signalling systems also varried by RR and time period. Some use smash boards, semaphores, lighted semphors, straight signals, and round signals of various number of lights. There are even more than this. But I can’t remember them. Obviously they were used mainly for mainlines and branhlines.
I saw a link that explained how signaling worked on the prototype for yards and mainlines. If I find it, I’ll post it here.
I yardmaster in yards with signals, and without signals.
First, the yardmaster controlls all movement within a yard. The road train needs the yardmaster’s authority to enter the yard. In the event that signals are used inside the yard, there is usually an operator nearby or direct line to the dispatcher that contols the signals. Sometimes, the signals, in the absence of a road train, are set to automatically display signals for switching crews, without the dispatcher having to keep putting it up.
Second, all movements within a yard are to be made at restricted speed. The short from is, a speed which will permit stopping within one half the range of vision, short of an obsturction. So, should two trains come upon each other, they are suppose to be able to stop before anything happens.
Most yards don’t have signals in the yard. At one time kerosene lanterns were used on the switch stands to show which way the switch was lined and the BNSF, in Pasco yard, (which used remote controlled power switches) had signals on the switch motors that showed green or yellow to show whether they were lined for the normal route or reversed but they didn’t control train movement (other than to advise not run through an incorrectly lined switch). In CTC territory the dspr controls movement out of the yard and onto the main while the yardmaster controls movement into the yard, generally by radio. In non-CTC territory the main and yard tracks are generally all within yard limits and a yard engine wanting to go onto the mainline would line a switch, which would throw block signals red at both ends of the block, and wait a set period of time before fouling the main. This would, of course, only be done if the movement wouldn’t conflict w/ the main line movement.
At the BNSF Cherokee yard here in Tulsa the yard limits extend quite aways past what would be recognized as the yard (approx 1 mile or so). The yard master control all movements into and out of the yard. A road train will remain in CTC territory with the subdivision dispatcher until they arrive at a given point. At this point they would contact the yardmaster and advise that they are at the control point. The yardmaster would advise to proceed into the yard or hold.
Here in Tulsa, for example, Westbound trains proceed to East Tulsa (2 track main) usually on main 1 under the control of the Cherokee Sub Dispatcher. The dispatcher will coordinate the arrival with the Cherokee yardmaster (Trimmer Tower) and advise the crew if they would be going in or waiting. The crew would contact Trimmer Tower once they reach the contol point, which is Trenton Street Bridge. The yardmaster will give them authority to proceed or hold.
This works both ways. Trains leaving the yard do so under the control of Trimmer Tower. Coordination with the Cherokee Sub dispatcher is done and the train will proceed usually on main 2 to East Tulsa. Once they are in East Tulsa, they are under control of the dispatcher and in CTC territory.
BNSF in Tulsa Yard limits actually end at a point called Urban and CTC begins there with two main tracks until reaching East Tulsa, then 1 main track. But the coordinating point is East Tulsa.
Yard Limits (as defined by the Operating Rules) are NOT the physical limits of a yard. Yard Limits are a portion of the main line designated by special instuctions, and identified by signs.
Yard Limits is a operating scheme used in areas where there is a great deal of switching traffic across a mainline. Operation with-in Yard Limits, is governed by the dispatcher and will be made under restricted speed, unless otherwised authorized by signal indication. A Yardmaster has no authority in Yard Limits.
Yard Limits, as defined by crew agreements mark the place where the train is “arrived” at the yard, or the place where yard crews are concidered out of terminal, which may or may not be the physical limit of the yard.
The physical limits of the yard, and the yardmaster’s authority are designated in the time-table. Real world example from my terminal, South Philly Greenwich Yard:
My authority over the yard (as designated by the time-table) begins at CP Penrose (which is 2 miles from the actual yard). The yard limit (as defined by the crew agreement) is CP 58th Street (6 miles further down the line). No where are there Yard Limits as defined Operating Rules.
Hi faraway
if the yard is in signaled area it will have two areas arrival and departure
which have naturaly enough arrival and departure signals there will probably be directing signals as well
There will also be ground signals in and out of the non signaled part of the yard where the shunting is done that will also have switch stands rather than switch machines.
regards John
A yard is usually designed in such a way that the switcher never has to cross the mains. Only arrivals and departures should need to interact with the mains, and as previously mentioned may be controlled by dwarf signals (dwarf = low to the ground).
Every yard should have a “lead”. This is a track that often runs parallel to the main, and is at least as long as the yard’s longest track. This allows trains to be moved without ever blocking the main. The lead can be connected to the main, and that connection is the perfect place for a signal.
Switch crews working in the yard are generally free to move, unless multiple crews are working, in which case they would most likely be working different sections of a very large yard, and wouldn’t really be in each other’s way. No signals for this type of activity, just radio communication.
Pick up a copy of John Armstrong’s Track Planning For Realistic Operation. It is available online.
Listening to some old-timers, I remembered, there is another use for signals in the yard.
In the days before radio’s, many hump yards had “hump lights” positioned along the hump lead. These were (at least on the Pennsy) three light signals controlled by the hump conductor, and instructed the hump engineer what to do:
Green: Hump Speed
Yellow: Back Up
Red: Stop
It relates to question 1 - How train crews are controlled in the yard.
Before radio was widespread, which in some places was well into the 1970s, all movement was done with hand, light and whistle signals. Yardmasters, sometimes had loudspeakers, and call boxes in the yard, as well as the ablity to override the hump lights.
Yes, but he isn’t asking about hump yards, at least not the way I read the part leading up to the question. He is asking about flat yards and how they interact with mains.
Hump yards are not typical, though they did exist back in the 60’s.
