There are many ways of moving people and equipment vertically through amultistory building. The most common method is using the stairs. Most modern commercial buildings have one or more pieces of equipment that allow them to move people and objects mechanically. This equipment falls into the general category of vertical transportation. Vertical transportation systems that are most commonly found in the hospitality buildings include elevators, escalators, and dumbwaiters.
Elevators are the most common type of vertical transportation equipment found in hospitality properties. They are equipped with numerous redundant safety devices, resulting in a form of transportation that is one of the safest in the world for transporting both equipment and passengers. There are three basic types of elevator equipment, each serving a different set of operational parameters hydraulic elevators, geared elevators, and gearless elevators.
Hydraulic elevators are the most prevalent type of elevator. They are designed to be used in buildings with a relatively low vertical rise, usually serving between 2 and 6 stops. Traditional hydraulic elevators operate using a piston and cylinder arrangement, where a cylinder is buried in the ground beneath the elevator cab and a piston, attached to the bottom of the cab, travels up and down the cylinder to raise and lower the elevator. The piston is propelled by fluid, usually a specially formulated oil that is pumped in and out of the cylinder. This mechanical process results in a relatively slow elevator, with speeds ranging from 50 150 ft/min (0.254 0.762 m/s). Many new hydraulic elevators are being installed that use piston and cylinder arrangements that are not buried in the ground, which greatly reduces installation time and expense, since it does not require a hole to be drilled into the ground for the cylinder. The ‘holeless’ hydraulic elevator also reduces the risk of a hole forming in the side of the cylinder which can result in hydraulic fluid leaking into the surrounding ground.
Buildings that require greater speed and travel height typically turn to geared and gearless elevators to accomplish the task. Geared and gearless elevators do not use a piston and cylinder arrangement to raise and lower the elevator. Instead, the elevator cab is attached to a ‘rope’, or wire cable, that travels over a grooved sheave at the top of the hoist way. The other end of the rope is attached to a counterweight that travels in the opposite direction of the elevator. Geared elevators are designed to serve mid rise buildings (i.e., 6 20 stops) at medium speeds, ranging from 250 500 ft/min (1.27 2.54 m/s). Gearless elevators are designed to serve buildings with a higher rise, and usually travel at higher speeds, ranging from 400 1500 ft/min (2.03 7.62 m/s).
Escalators are moving staircases. They are complex mechanical systems that are very effective at moving large volumes of people over relatively short distances. Some escalators are capable of moving more than 6000 passengers per hour. The escalator carries passengers from one floor to another. Escalators are the most expensive type of vertical transportation equipment, both to install as well as to maintain. The expense is due to the complexity of the equipment and the hundreds of moving parts in the system that must be maintained regularly and properly to insure safe and consistent operation.
The basic parts of an escalator include the steps, the handrail and balustrade, the truss, motors, and safety equipment. The steps are the part of the escalator that passengers stand on. The handrail is a moving rail that travels in sync with the steps. The handrail sits on top of the balustrade, which rises vertically above the steps. The balustrade may be skinned in metal or may be made of glass. The truss is the structure in which the escalator components are located and provides the support for the entire system.
A modern hotel escalator may be equipped with several safety devices to prevent injury, depending on the age of the escalator and national and local code requirements. Some of the more common devices include lighting at the top and bottom landing, lines painted on the steps to help passengers identify the edges of the steps, manually operated emergency stop switches, stop switches that are activated in the event of equipment failure, and special panels designed to close the gap between the balustrade and the moving steps.
Dumbwaiters are small elevators that are designed to carry materials only. Dumbwaiters are usually hoisted using a drum style machine, where a cable is wrapped around a drum. The dumbwaiter descends when the cable is unwrapped and ascends when the drum reverses direction and rewraps the cable.
Dumbwaiters can land at floor level, or anywhere above the floor to facilitate easy loading and unloading of materials. Foodservice operations will often use dumbwaiters to trans port food to service areas located on different floors, that is, the food preparation areas, as well as to transport dirty dishes to a kitchen stewarding area on a different level. Hotels often use dumbwaiters to transport linens as well as to move room service food and beverages.
Unlike elevators, there are no safety systems built into a dumbwaiter that make it safe for passengers to ride. It is important that hotel and restaurant managers ensure that their employees do not ride in dumbwaiters.
Starkest, G. R. (Ed.), (1998). The vertical transportation handbook (3rd ed.). New York: Wiley.