In old days when modes of transportation were not there, people used to walk to the places they wanted to reach. For transportation of goods, bullock carts, camels, horses, etc. were often used. All this was meeting the mobility requirements as the settlements were not too dispersed.
As human settlements dispersed more and more, urban modes of transportation evolved. Buses, automobiles, trains, etc. came up and they provided a lot of convenience to the travellers.
With the rapid advancement in the development of tall building and public facilities, it became paramount to address the need to transportation of pedestrians and also of goods. With multi-storeyed buildings or large shopping complexes or airports, it is unreasonable to expect the user to travel across the buildings/ public facilities by means of walking alone, at least not in a timely manner. Towards this end, innovations sprung up facilitating movement of pedestrians as well as goods in large shopping malls, multi-storeyed residential buildings, airports and other public facilities.
Today, elevators are a commonplace necessity in all residential buildings/ public facilities allowing movement of passengers and goods. Along with these, escalators and moving walkways have also become an integral part of urban lives. These enabling devices are expected to be present in most of the public facilities. Wherever elevation change is needed, elevators/ escalators or both are employed and allow pedestrians to traverse, with ease, longer distances than they could possibly do without such enabling devices. Similarly, moving walkways are of importance in dispersed facilities like airports.
LIFTS Vs ESCALATORS Vs MOVING WALKWAYS
All the three are enabling technologies to facilitate movement of personnel and goods across large residential/ public facilities. Lifts and Escalators are vertical building transportation systems whereas moving walkways are horizontal transportation system.
‘Lifts’, a prevalent terminology in UK, is referred to by ‘Elevators’ in US. An elevator is a hoisting or lowering mechanism, designed to carry passengers or freight, and is equipped with a car and platform that typically moves in fixed guides and serves two or more landings. Primarily they are of two types:electric traction type and hydraulic type.
· Traction elevators have an elevator car and counterweight attached to opposite ends of hoist ropes. The hoist ropes pass over a driving machine that raises and lowers the car. Traction elevators run on load-bearing rails in the elevator hoistway. Traction elevators are most often used in mid-rise and high-rise buildings with five or more floors.
· On the other hand, hydraulic elevators are raised by forcing pressurized oil through a valve into a steel cylinder. The pressure forces a piston to rise, lifting the elevator platform and car enclosure mounted on it. The car is lowered by opening the valve and allowing the weight of the car to force oil from the cylinder in a controlled manner. When the valve is closed the car is stopped. Since the weight of hydraulic elevator cars is borne by the piston, there is no need for a structural framework or load-bearing rails. Hydraulic elevators are commonly found in low-rise buildings with two to five floors.
Different from lifts, escalators are moving staircases. Escalator can be described as moving stairs typically used to carry large number of people at high volumes through a limited no of floors. These are commonly used in high density areas or where sudden traffic surges are expected at times; for example at discharge times from offices, railways underground stations, airport terminals, theatres, shopping malls and departmental stores. In such applications, escalators will provide shorter travel time than elevators because elevator cars are limited in size and passengers have to wait longer for the service.
Moving walkways are also referred to by conveyors. They are horizontal, moving belt transportation systems enabling large number of people to travel through longer distances. They are suited for airports, high traffic areas like transit stations, etc.