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  2. Railway block code - Wikipedia

    en.wikipedia.org/wiki/Railway_block_code

    Box B sends 4 bells to box A. (Acknowledgement, if in the position to accept the train giving permission for box A to signal the train into the block controlled by B.) (when the signalled train enters the portion of line between A and B.) Box A sends 2 bells to box B (Train entering section) as the train passes box A and enters the block ...

  3. Train horn - Wikipedia

    en.wikipedia.org/wiki/Train_horn

    A train horn is an air horn used as an audible warning device on diesel and electric-powered trains. Its primary purpose is to alert persons and animals to an oncoming train, especially when approaching a level crossing. They are often extremely loud, allowing them to be heard from great distances.

  4. Automatic Warning System - Wikipedia

    en.wikipedia.org/wiki/Automatic_Warning_System

    A train is driving towards a signal that shows clear (green). The train runs over the AWS magnet (which is two magnets, first a permanent magnet and then an electromagnet). The electromagnet is energized. The AWS receiver detects a magnetic field in the sequence: South, North. The south pole comes from the permanent magnet, and the north pole ...

  5. Electric bell - Wikipedia

    en.wikipedia.org/wiki/Electric_bell

    When an electric current is applied, it produces a repetitive buzzing, clanging or ringing sound. Electromechanical bells have been widely used at railroad crossings, in telephones, fire and burglar alarms, as school bells, doorbells, and alarms in industrial areas, since the late 1800s, but they are now being widely replaced with electronic ...

  6. Train noise - Wikipedia

    en.wikipedia.org/wiki/Train_noise

    Several distinct sounds are created by various parts of the train, such as engines, traction motors, brakes, and the wheels rolling on the rails. Roughness and irregularities on the wheel and rail surfaces are a source of noise and vibration. Rail joints and squats on the rail cause a familiar "clickety-clack" sound as train wheels roll over them.

  7. Train whistle - Wikipedia

    en.wikipedia.org/wiki/Train_whistle

    As train whistles are inexpensive compared to other warning devices, the use of loud and distinct whistles became the preferred solution for railway operators. Steam whistles were almost always actuated with a pull cord (or sometimes a lever) that permitted proportional action, so that some form of "expression" could be put into the sound. Many ...

  8. Doorbell - Wikipedia

    en.wikipedia.org/wiki/Doorbell

    Doorbell mechanism from 1884 in Andrássy Avenue, Budapest Antique mechanically operated shop doorbell on a torsion spring. William Murdoch, a Scottish inventor, installed a number of his own innovations in his house, built in Birmingham in 1817; one of these was a loud doorbell, that worked using a piped system of compressed air. [1]

  9. Bell code - Wikipedia

    en.wikipedia.org/wiki/Bell_code

    Stop train 1—1: Zone of speed restriction over, resume prescribed speed 1—2: Close doors: 2: Ready to start: Start train 2—2: Do not open doors: Passing automatic signal at 'on' 3: Set Back: Guard required by driver 3—1: Lock central door locking: 3—2—1: Testing doors: 3—3: Guard required by driver, or guard or driver to speak on ...