Search results
Results from the WOW.Com Content Network
Level crossing signals. Level crossing signals are the electronic warning devices for road vehicles at railroad level crossings. Level crossings can be operated in various ways. In some countries such as the UK, the warning devices are more often than not activated by remote control, I.e. an operator pressing buttons.
The first signals employed on an American railroad were a system of flags used on the Newcastle and Frenchtown Turnpike and Rail Road in the 1830s. The railroad then developed a more effective system consisting of wooden balls, painted red, white or black, and hoisted up or down a pole on a rope-and-pulley system.
A level crossing is an intersection where a railway line crosses a road, path, or (in rare situations) airport runway, at the same level, [1] as opposed to the railway line crossing over or under using an overpass or tunnel. The term also applies when a light rail line with separate right-of-way or reserved track crosses a road in the same fashion.
A Magnetic flagman wigwag signal in use in southern Oregon, June 2007. Wigwag is a nickname for a type of railroad grade crossing signal once common in North America, referring to its pendulum -like motion that signaled a train's approach. The device is generally credited to Albert Hunt, a mechanical engineer at Southern California 's Pacific ...
A level junction (or in the United Kingdom a flat crossing) is a railway junction that has a track configuration in which merging or crossing railroad lines provide track connections with each other that require trains to cross over in front of opposing traffic at grade (i.e. on the level). The cross-over structure is sometimes called a diamond ...
Railway signalling. A Class 66 locomotive (right) is waiting at a red signal while a First Great Western (now Great Western Railway) passenger train (left) crosses its path at a junction. Railway signalling (BE), or railroad signaling (AE), is a system used to control the movement of railway traffic. Trains move on fixed rails, making them ...
Application of railway signals. Semaphore stop signals protecting the convergence of two tracks into one. The application of railway signals on a rail layout is determined by various factors, principally the location of points of potential conflict, as well as the speed and frequency of trains and the movements they require to make.
North American railroad signaling. Standards for North American railroad signaling in the United States are issued by the Association of American Railroads (AAR), which is a trade association of the railroads of Canada, the US, and Mexico. Their system is loosely based on practices developed in the United Kingdom during the early years of ...