Signals

Types of Semaphore Signals

For many years after the demise of steam, the route on the Medway Valley Line still had much charm, not only because the original station structures remained, but also due to the retention of semaphore signals. However, a line re-signalling programme got underway in earnest in December 2004 and by October of the following year, colour lights were controlling the line. But the planned layout is dated between 1945 – 1960.

To understand the British signals you can find a lot of information of the real thing on the internet.

Position_signals

The following types of semaphore signals are relevant for the Medway Valley Line. We use the upper quadrant versions.

SemastopA Home Signal or Starting Signal (left) is the stop signal described above.  It is placed at the entrance to a block and, when showing “stop”, the train is forbidden to enter the block.  When a signal shows a stop or other restrictive indication, it is said to be “on”.  A signal showing a proceed indication is said to be “off”.
Traditionally, at a station, each track would have two stop signals.  One, protecting the entrance to the block, was called the Home Signal.  The other, protecting the exit towards the next station or signal box, was called the Starting Signal or Starter.

As mentioned above, this is a stop signal showing a proceed indication – it is “off”.  The train may enter the block at normal speed.  In effect, this means the maximum speed applicable to this section of line and the type of train.

SemadistTo give advanced warning of the indication of a stop signal, a “distant” signal is sometimes provided (left).  This operates in the same way as the stop signal but gives either a “caution” indication (it is said to be “on”), shown on the left, or a proceed indication, on the right.  If the distant is “on”, a yellow light shows at night. The distant signal showing “on” tells the driver that the next stop signal is also “on” and that he will have to stop there.  The distant signal was, if possible, located ¾ mile (1200 metres) before the stop signal.  A single distant signal will often provide a warning for both home and starting signals at a station.

The distant shows a yellow (on) or green (off) light at night.  Remember that the distant signal normally refers to more than one consecutive stop signal ahead.  Thus, when the distant is off, the driver knows that all the relevant stop signals are off too.  Each stop signal does not have its own distant signal in rear.

Semabanshunt-onoff

As semaphore shunt signals were disc signals used to improve visibility.  The operation was the same and the arm was usually positioned on a white disc.  Many of these can still be seen in the UK.

Signal plan

Sierd Jan Tuinstra developed a signal plan for the layout of the Medway Valley Line.

Signal-plan

Click on the image to enlarge

  • SB    Signalbox
  • CP    Catchpoint
  • 1       Up Starter
  • 2       Up Advanced Starter (Limit of shunt)
  • 3       Down Starter
  • 4       Up Home
  • 5       Down Distance
  • 6       Down Home
  • 7       Up Home Beltring & Branbridges
  • A-J   Ground Disc Signals (Shunting)

Model semaphores

Ratio produces good looking semaphores.

  • Ratio 490 Sr Home Semaphore Signal Kit OO Gauge – Home signal/ Starting signal
  • Ratio 491 SR Distant Signal Kit
  • Ratio 465 GWR Ground Shunt Signals x 4 Plastic Kit OO Scale

3 thoughts on “Signals

  1. Pingback: Signals | Medway Valley Line

  2. You refer to the distant signal repeating the position of the next stop signal. That is if the Distant is at caution, the next stop signal will be at Danger. May I please correct this. Imagine a long stretch of main line and a train in the dark travelling at 90 miles per hour. If there is an ‘outer home, a home and an advanced starter, the distant signal can only be cleared if ALL the other signals on that line controlled by the next signalbox are already clear. If the first home signal is at danger, the distant will warn the driver by being at caution as you said. If the starter cannot be cleared to permit the train to proceed into the block section, the preceding signal will be held at danger and the distant will be at caution. the driver will reduce his speed being prepared to stop at the next signal. Just before he does stop the home signal may be cleared and the driver will proceed slowly to the next stop signal at danger, etc. This ensures that if the train is not permitted to go past the advanced starter, it is cautioned at each signal. This is all rather complicated and not a ruling usually followed on a model railway. Good luck with your model and please call if you need any more signalling information.

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