Canadian Railway Operating Rules
(CROR) Signals & Interpretations

Note: This method for locating a kicker car is not approved by anyone. It's something I thought of during my freight conductor course (in 2012) and should save a lot of time when you're trying to locate a specific railcar.

Blinking signals.

Tapping on a light in the first column will toggle it between blinking and non-blinking.

Tapping on an empty box in the second column will remove the selected light or letter plate from the pattern.

 Designed to help you learn CROR signals and their definitions.

You can either select your own signal pattern and mast style or have some 'fun' and let the system pick a pattern for you [Gen Sig]. Please be patient, the GenSig module may take a few guesses before it finds a valid combination.


Blinking
Tapping on a light in the first column will toggle it between blinking and non-blinking.
Tapping on an empty box in the second column will remove the selected light or letter plate from the pattern.


MODE lets you control the range of signals generated using [Gen Sig].
• FULL allows the full range of signal and letter plate combinations to be displayed (including random blacked out signals, plus rules 27a, 27b and 27b Exception).
• FULL/NB (no blacked out signals) allows the full range of signal and letter plate combinations to be displayed. Blacked out signals will not be displayed.
• PARTial limits the combinations by eliminating blacked out signals and letter plates.
• BASIC is the same as PARTial but also eliminates blinking signals.
* Selecting one of the reduced MODE options will increase the time required to generate a valid signal combination.


Complete CROR documentation is a link to Transport Canada's website where the entire CROR document is available online or as a downloadable PDF. Downloading the PDF to your device will keep the information accessible even when you're offline.


Unknown (valid signal with letter plate)
Have you seen Unknown (with letter plate) with Try removing the letter plate as the description?
Here's what's really going on:
• Let's use yellow over green with an "R" plate as the signal pattern for this example.
• This is a legitimate signal even though it's listed as unknown.
• The letter plate is a permanent fixture and only applies to a few signals (red signals in the case of an R plate).
• Yellow over green is signal #407 (clear to medium) and the presence of the R plate does not affect the signal's meaning.
• Removing the signal plate from the pattern and tapping solve will show the correct definition.
• Designing the app to handle letter plates in this manner was done to simplify the initial design work and make maintenance easier.


Kicker Calculator
The Kicker Calculator will tell you the maximum number of brake checks that should be required to determine which railcar has a brake problem ("Kicker"). The calculation is based on a computer science algorithm known as a "binary search" where a list (railcars in this case) is halved and halved again until the item (railcar with a brake problem) is found. Once the car is located the air brakes for that car can be bypassed and your log updated.
The value range that can be entered for the number of railcars is from 1 to 1000.

* This method for locating a kicker car is not approved by anyone. It's something I thought of during my freight conductor course and should save a lot of time when you're trying to locate a specific railcar.


Have fun.
Rob

Speed definitions.

The railways use words to describe speed limits rather than post an actual number. Come to think of it, using a speed description means the speed limits can be changed anytime without replacing the signs.

LIMITED: Maximum 45MPH.
MEDIUM: Maximum 30MPH.
DIVERGING: Maximum 25MPH.
SLOW: Maximum 15MPH.

REDUCED: A speed that will permit stopping within 1/2 the range of vision of equipment.

RESTRICTED: Same as reduced, also be prepared to stop short of a switch not properly lined and in no case exceeding SLOW speed. Be on the lookout for broken rails.

Signal reading tips

1. If the signal is not all RED it is not red at all. All red = stop.

2. If you have only 1 LIGHT with colour and it's YELLOW, the name will end with the words '...TO STOP'.

3. If you have only 1 LIGHT with colour and it's GREEN, the name will end with the words '...TO CLEAR'.

4. If you have a SOLID YELLOW ON TOP, the name will start with the words 'CLEAR TO...'.

4a. If you have a SOLID YELLOW ON THE BOTTOM and NO OTHER COLOURS, then it's RESTRICTING.

5. When a signal has 2 lights with colour and the colour is not in the top position (ex: top is red). Then the following modifier applies when naming the colours:
   flashing green = Limited
   solid green = Medium
   yellow (solid or flashing) = Slow

*Exceptions*
On a Double LowMast signal:
   2 YELLOW lights is 'CLEAR TO SLOW'.
   2 GREEN lights is 'CLEAR'.

Hint:
When naming the colours always start with the colour in the highest position on the signal and finish with the name of the lowest colour.
The highest colour tells you what to do at the signal (ex: 'clear to...') and the lowest colour tells you how to approach the next signal (ex: '...stop').

** Signal Modifiers **

Letter Plates:
   A: Either slow or stop, depending on signal.
   DV: Diverging.
   L: Limited.
   R: Restricting. Adding R to a 'stop & proceed' changes it to 'proceed at RESTRICTED speed'.

Flashing:
A flashing light will make a signal more permissive. A 'Medium to Clear' signal with a flashing green, becomes a 'Limited to Clear'.

Please keep in mind that even though a signal may be logically interepreted to mean something doesn't mean that it's the correct interpretation.
   For example:
      Green
      Red
      Green
      Is rule 407 - Clear to Medium.
Now, consider what happens when there is a L plate attached to the mast. The L plate should modify the signal to mean clear to limited. However as per the rules clear to limited will never be displayed like that. The ruling is correct but the correct interpretation of that signal is clear to medium.
Thanks to Jesse D for pointing this out and providing a great example.

** Mast Signal Position **

TOP: Governs HIGH speed route.
MIDDLE: Governs MEDIUM speed route.
BOTTOM: Governs SLOW speed route.

Signal numbers, their names and definitions

Signals Imperfectly Displayed:
[27a]
[27b]
[27b Exception]

Locating a Kicker car.

The Kicker Calculator will tell you the maximum number of brake checks that should be required to determine which railcar has a brake problem ("Kicker"). The calculation is based on a computer science algorithm known as a "binary search" where a list (railcars in this case) is halved and halved again until the item (railcar with a brake problem) is found. Once the car is located the air brakes for that car can be bypassed and your log updated.

For example...
You have a train consisting of 100 freight cars. During the course of your trip you start having a brake problem which the crew decides is probably a kicker. At this point you would usually choose to ignore it, log the problem and have it fixed when you get to the yard. Your initial reaction to locating the problem car is that you'd have to check every car until you found it and that could take all day (or night). But what if there was an easy way to locate the problem car and bypass its air brakes?

That's where a binary search can be useful and here's how it would work with a 100 car train:

  • Walk to the 50th car (½ the length of the train), close the angle cock on that car and ask the engineer to perform a brake test.

  • If the brake problem has disappeared then the problem car is further down the line. Now you would open the angle cock, proceed to the 75th car (½ way from your current position to the end of the train) and repeat the test.
  » OR «
  • If the brake problem persists then the problem car is between you and the engine. Now you would open the angle cock, proceed to the 25th car (½ way from your current position to the head of the train) and repeat the test.

  • Repeat the process by halving the distance between your current position and your previous position until the railcar in question has been located.

Continuing with this example, let's say the problem continued when the 50th car was checked but disappeared when the 25th was checked. That would indicate the problem railcar is between the 25th and 50th railcars, you would then proceed to the 37th car and repeat the test. As you can see the number of cars to be checked is halved with each brake test.

A train with 100 cars should require a maximum of 7 brake tests to locate the car with the brake problem. A train with 50 cars should require a maximum of 6 brake tests while a train consisting 200 cars should only require 8 brake tests.

Locating the problem railcar while you're on the road can make for a less frustrating trip for the crew, save the company money by maintaining their schedule and since the problem railcar has been located it can be repaired/returned to service quicker.

* This method for locating a kicker car is not approved by anyone. It's something I thought of during my training course and should save a lot of time when you're trying to locate a specific railcar.

** I discussed this idea with CP Rail during my job interview, their reaction was something like ...OMG!! Why didn't we think of this..it's brilliant... Out of curiosity, does anyone know if they implemented it?