A railway air brake is a railway brake power braking system with compressed air as the
operating medium. Modern trains rely upon a fail-safe air brake system that is based
upon a design patented by George Westinghouse on March 5, 1868. The Westinghouse
Air Brake Company was subsequently organized to manufacture and sell
Westinghouse’s invention. In various forms, it has been nearly universally adopted.
The Westinghouse system uses air pressure to charge air reservoirs (tanks) on each car.
Full air pressure signals each car to release the brakes. A reduction or loss of air pressure
signals each car to apply its brakes, using the compressed air in its reservoirs.
Traffic lights, also known as traffic signals, traffic lamps, traffic semaphore, signal lights,
stop lights, robots (in South Africa), and traffic control signals, are signaling devices
positioned at road intersections, pedestrian crossings, and other locations to control
flows of traffic.
The world’s first, manually operated gas-lit traffic signal was short lived. Installed in
London in December 1868, it exploded less than a month later, injuring or killing its
policeman operator. Traffic control started to seem necessary in the late 1890s.
A tape measure or measuring tape is a flexible ruler and used to measure distance.
It consists of a ribbon of cloth, plastic, fibre glass, or metal strip with linearmeasurement markings. It is a common measuring tool. Its design allows for a measure
of great length to be easily carried in pocket or toolkit and permits one to measure
around curves or corners. Today it is ubiquitous, even appearing in miniature form as
a keychain fob, or novelty item. Surveyors use tape measures in lengths of over 300
feet.
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