Top quality engineering
A typical modernization consists of controller equipment, electrical wiring and buttons, position indicators and direction arrows, hoist machines and motors (including door operators), and sometimes door hanger tracks. Rarely are car slings, rails, or other heavy structures changed. The cost of an elevator modernization can range greatly depending on which type of equipment is to be installed.
The technology used in new installations depends on a variety of factors. Hydraulic lifts are cheaper, but installing cylinders greater than a certain length becomes impractical for very high lift hoistways. For buildings of much over seven storeys, traction lifts must be employed instead. Hydraulic lifts are usually slower than traction lifts.
Modern Installations with more complex elevator arrangements have led to the development of more specific formulae such as the General Analysis calculation.