[DOC] [TLE] Elevator - Simple English Wikipedia, the free encyclopedia [PAR] They are generally powered by electric motors that either drive traction cables ... 
In a "traction" lift, cars are pulled up by means of rolling steel ropes over a deeply 
... For buildings of much over seven stories, traction lifts must be employed 
instead. ... the traditional, looped over-the-top traction rope routing of traction 
elevators. [DOC] [TLE] Full text of "Building Elevator Systems.haydanovic.webs.com.pdf" [PAR] The elevators can be broadly classified as either electric traction type or hydraulic 
type. ... The pressure forces a piston to rise, lifting the elevator platform and car 
..... TRACTION ELEVATORS machine room motor, cable, sheaves steel cables 
control .... These are generally used on taller structures with more than 10 stories. [DOC] [TLE] How do elevators and lifts work? - Explain that Stuff [PAR] Apr 28, 2016 ... It wasn't just brilliant building materials such as steel and concrete that ... A 
system of strong metal cables and pulleys running between the cars and the 
motors. ... the elevator gives you potential energy when you're going up and it 
takes ... If it does the lift in 10 seconds, it has to work at a rate of 50,000... [DOC] [TLE] Mechanical and Electrical System Lifts/Elevators and Escalators [PAR] Lift began as simple rope or chain hoists. Lift is essentially a ... means of rolling 
steel ropes over a deeply grooved pulley .... To install a hydraulic elevator in a 
10-story building, for example ... The other disadvantage of hydraulic elevators is 
that they're ... Geared Traction machines are driven by AC or DC electric motors. [DOC] [TLE] Buildings | Free Full-Text | Tall Buildings and Elevators: A Review of ... [PAR] Sep 17, 2015 ... In geared machines, the electric traction motor drives a reduction ... In a 
conventional elevator system, that energy is dissipated as heat through a heat 
resister. .... before the weight of the steel rope becomes unsupportable over that 
... each floor of a 31-story building is more than 830 m2, which is equivalent... [DOC] [TLE] The Nuts & Bolts About Elevators | T.L. Shield & Associates, Inc. [PAR] Jun 3, 2014 ... Hydraulic elevator systems lift a car using a hydraulic ram, a fluid-driven ... A tank 
(the fluid reservoir); A pump, powered by an electric motor; A valve ... To install a 
hydraulic elevator in a 10-story building, for example, you would ... The other 
disadvantage of hydraulic elevators is that they're fairly inefficient. [DOC] [TLE] Elevator - New World Encyclopedia [PAR] In the past, elevator drive mechanisms were powered by steam and water 
hydraulic pistons. ... For buildings of much over seven stories, traction elevators 
must be .... Although hydraulic freight elevators exist, electric elevators are more 
energy .... If the compensation system uses cables, there will be an additional 
sheave in... [DOC] [TLE] The new lift technology that will let cities soar far higher - The Guardian [PAR] Aug 1, 2014 ... The UltraRope could allow for buildings to tower up to 1km, higher than ... same 
technology could necessitate changing elevators as many as 10 times. ... 
Eschewing woven steel cable in favour of carbon fibre, the ... woven cable, safety 
brake, electric motor, core, traction and elevator .... more on this story... [DOC] [TLE] Elevator - USM [PAR] They are generally powered by electric motors that either drive traction cables 
and ... In a "traction" lift, cars are pulled up by means of rolling steel ropes over a 
deeply ... For buildings of much over seven stories, traction lifts must be 
employed instead. .... Safety testing of mine shaft elevator cables is routinely 
undertaken. [DOC] [TLE] The Electrical Ups and Downs of Elevator Design [PAR] May 1, 2003 ... As they review the plans and the construction site, they may have conflicting ... 
When you're designing an electrical system for a building, don't let ... Traction 
elevators raise and lower the elevator cab with cables, .... that it's about to switch 
over to emergency power  preferably 30 sec or .... Oct 10, 2016. [DOC]

Question: In buildings over 10 stories they're powered by electric traction systems & lifted by steel cables
Answer: Elevators