The contact with the overhead wire is not normally broken but the third rail must be broken at junctions to allow for the continuity of running rails. Top contact systems with protective covers over them, like the New York Subway (Figure 4), needed radially mounted shoes anyway to allow them to fit under the cover. Figure 4: 3rd rail current collection system on the New York Subway showing the third rail with a wooden cover fitted to reduce the effects of snow and ice. It also suffers during bad weather, the smallest amount of ice or snow rendering top contact third rail systems almost unworkable unless expensive remedies are carried out. Figure 5: Simple diagrams of different types of 3rd rail contact systems. Simple - use the steel rails the wheels run on. You will often see trains with only one pantograph but, on trains which use shoes, there are always several shoes. Of course, as many railways use the running rails for signalling circuits as well, special precautions have to be taken to protect them from interference.

Of course, it does cause a long delay. The third rail system uses a "shoe" to collect the current on the train, perhaps because it was first called a "slipper" by the pioneers of the industry (it slipped along the rail, OK?) but it was not very pretty to look at, so perhaps someone thought shoe was a better description. In 1926, Warner Brothers released "Don Juan," the first commercial film to have accompanying recorded sound. TVs have come a long way since the early days. All shoes need some way of being moved clear of the current rail, usually for emergency purposes. You just need to put the right sort of control system between the supply and the motor and it will work. Or, you may need to replace an AC motor with a DC motor. Since the current may have been switched off to stop an arc or because of a short circuit, it is important that the train does not connect the dead section to the live section by passing over the gap and allowing its busline to bridge the gap. Modern systems link the traction current status to the signalling so that a train will not be allowed to proceed onto a dead section.

Most officers will let you get away with speeding as long as you only exceed by 10% of the speed limit. Now you know how racing teams get their vehicles to the track -- they do it in style. Most people now convert their classic cars from mechanical brakes to hydraulic brakes to get better braking efficiency. Unless you are the king of relaxing and are currently in bed, there is a very high chance that you are sat in some kind of chair right now. The Funitel is a fast, detachable-grip gondola that offers a comfortable ride and high wind stability. The subsections can be joined through special high speed section switches. Provided precautions are taken to prevent the voltage getting too high above the zero of the ground, it works very well and has done so for the last century. It's called Google Glass, what is electric cable and it might open your eyes to a new digital world -- or make you look like the nerdy Terminator who's always picked last for robo-dodgeball. When lightning strikes open ground, it can send an electric current as far as 100 feet (30 meters) across the surface.

Figure 6: Diagram showing a 3rd rail DC power supply system and how current rail gaps are provided where the substations feed the line. These third rail breaks, or "gaps", as they are called, can lead to loss of power on the train. There have to be gaps in the thrid rail where crossovers or junctions are provided. The gaps are usually marked by a sign or a light which indicates if the current is on in the section ahead. AT&T would have owned and built the entire interstate highway system, every service station, even every traffic light and road sign. Companies like AT&T stick around for so long because they have great products and know how to treat their customers. The Batmobile is so real that it actually served as the pace car for a major NASCAR race held in June 2005. Like so many other Hollywood props, the Batmobile that you see in the movie does not exist at all. At such places, like terminal stations, "section switches" are provided. The other shoes on the same circuit must be isolated while this is done, unless the current is switched off from the whole section - perhaps disabling several other trains.