Origins of transportation systems in buildings
Hand powered lifts or hoists in various forms have been in use since the days of the pyramid constructors in Egypt (c. 2600 BC) and it is claimed that, in China, hand powered winches were used to draw water as far back as 2200 BC. In 236 BC, in ancient Greece, Archimedes developed a lifting device in which the hoisting ropes were coiled around a winding drum. The Roman Emperor Titus used elevators to raise the gladiators and wild animals to the level of the arena of the newly-built Coliseum in 80 AD. Throughout medieval times, lifts and hoists were commonly used in the construction of castles, churches and monasteries.
The development of steel-framed buildings in the USA enabled buildings to be constructed to heights impossible with conventional foundations. This led to a need for transportation systems capable of conveying people to these heights in safety and comfort. In 1853, Harper’s Magazine remarked on ‘the introduction of a steam elevator by which an indolent or fatigued or aristocratic person may be borne up to the third, fourth or fifth floor.’
That same year, Elisha Otis established a company to manufacture hoists and, soon after, was able to demonstrate his new safety device at the Crystal Palace Exposition in New York City which ensured the widespread acceptance of vertical transportation systems in tall buildings. His famous words ‘All safe, gentlemen, all safe!’, spoken from the lift platform after the suspension ropes had been severed, are an important part of engineering history. Today the lift has the best safety record of any form of transportation and its installation in buildings is accepted as essential, especially to enable the elderly and people with disabilities to gain access to all kinds of buildings.
Many technological advances have occurred since Elisha Otis’ dramatic demonstration, but the basic components of a typical lift installation remain the same (machine, gearing and sheave, suspension, guide shoes and guide rails, safety gear, car and counterweight) and would still be recognisable to Otis. He would, however, identify important advances in the performance of lift systems, particularly in drive control, traffic control and signalling, monitoring and management systems, and in engineering and traffic design techniques. Such advances are amply illustrated by tall buildings such as Canary Wharf (London), the Eiffel Tower (Paris), the Empire State Building (New York), the World Trade Centre (New York), Sears Tower (Chicago) and Petronas Twin Tower (Kuala Lumpur). All these advances owe their significance to the use of the modern digital microcomputer and its associated software systems.
Purpose of Guide D. The purpose of CIBSE Guide D: Transportation systems in buildings is to provide guidance to practitioners involved in such systems. Guide D should also be of interest to architects and surveyors, and also facilities and building managers who may not be directly concerned with the design or installation of lifts and escalators but need to understand the advice offered to them by specialists. Not least, the Guide should be of value to students embarking on a career in mechanical, electrical or building services engineering and those already practising in these disciplines who wish to enhance their knowledge through a programme of continuing professional development.
Contents of Guide D. The design of any lift or escalator system must commence with a consideration of the traffic flows through the building for which the system is intended. The relevant factors, along with guidance on the location and arrangement of lifts and escalators within buildings, are discussed in section 2. The assessment of demand and fundamental principles of traffic planning are considered in section 3. Section 4 covers advanced planning techniques and the use of computer programs and includes the various mathematical models used.
Date added: 2023-01-05; views: 286;