The Science of Lifts
Contents |
[edit] How do Lifts Work?
A lift uses physical mechanisms that work together to lift or lower a car to various floors. The key components of a lift system include one or more car, a counterweight, an electric motor, metal cables, and various security systems.
Each part plays a particularly important part in the role of a lift system, and there are a lot of physical principles that are considered to ensure the lift stays functional and as safe as possible.
[edit] Conservation of Energy
This principle is one of the most widely known physical laws that is used. The law states that the total energy of a system that doesn’t interact with its surroundings remains constant. It is also referred to in the following statement:
“Energy is neither created nor destroyed; it transforms from one form to another.”
This would be, for example, converting electrical energy to kinetic energy within a motor. This law is particularly important in lift design, as it helps with the understanding of the raising and lowering of a lift car. Lift cars possess gravitational potential energy (GPE), which is the energy that an object possesses depending on how far the object is from Earth.
A lift that is high up has a greater GPE than if it was lower. Gaining this GPE must come from somewhere, and it comes from mechanical or electrical energy from the motor. To lift a car, more force needs to be applied than the car’s mass times by Earth’s acceleration due to gravity.
For example, lifting a 1,000kg car would require approximately 10,000N to lift using a single pulley, which is an immense amount of force.
[edit] The Physics of Counterweights
Counterweights provide a way to make life a lot easier when lifting a car to higher floors. Traditionally, counterweights weigh the same as when a lift is at half capacity. For example, if a car weighed 1,000kg and has a capacity of 1,000kg, the counterweight would weigh 1,500kg.
Because of this extra weight, it means that less force and, therefore, energy is needed to lift the car. For example, if the lift car is 3,000kg and the counterweight is 2,000kg, then 1,000kg is needed to be lifted as opposed to 3,000kg – an energy reduction of 66.7%.
Because of how they are implemented, it also means that the counterweight increases the acceleration that is required to raise the lift and decreases the acceleration that is required to lower the car, all of which helps to lower the amount of energy that is required by the motor.
As well as this, counterweights help to reduce the amount of energy that is used by the motor, which is beneficial in terms of increasing the environmental friendliness of lift systems. The goal is to ensure that the least amount of energy is used, whilst also maintaining the most efficient service possible.
[edit] Related articles on Designing Buildings
- A brief history of lifts over the years.
- Building engineering physics.
- Considerations When Installing a Residential Lift.
- Home lifts.
- Lifting platform.
- Lift motor room.
- Lift Standards: EN 81-20 and EN 81-50.
- Lifts and Escalators: A Quality Perspective.
- Lifts and Their Special Operating Modes.
- Lifts for buildings.
- Lifts for office buildings.
- Pulley.
- Smart elevators.
- The hidden mechanics of lift routing.
- The importance of service lifts.
- The world's fastest lifts.
--Nathan Massey 14:38, 11 Jul 2017 (BST)
Featured articles and news
Mixed reactions to apprenticeship and skills reform 2025
A 'welcome shift' for some and a 'backwards step' for others.
Licensing construction in the UK
As the latest report and proposal to licence builders reaches Parliament.
Building Safety Alliance golden thread guidance
Extensive excel checklist of information with guidance document freely accessible.
Fair Payment Code and other payment initiatives
For fair and late payments, need to work together to add value.
Pre-planning delivery programmes and delay penalties
Proposed for housebuilders in government reform: Speeding Up Build Out.
High street health: converting a building for healthcare uses
The benefits of health centres acting as new anchor sites in the high street.
The Remarkable Pinwill Sisters: from ‘lady woodcarvers’ to professionals. Book review.
Skills gap and investment returns on apprenticeships
ECA welcomes new reports from JTL Training and The Electrotechnical Skills Partnership.
Committee report criticises UK retrofit schemes
CIOB responds to UK’s Energy Security and Net Zero Committee report.
Design and construction industry podcasts
Professional development, practice, the pandemic, platforms and podcasts. Have we missed anything?
C20 Society; Buildings at Risk List 2025
10 more buildings published with updates on the past decade of buildings featured.
Boiler Upgrade Scheme and certifications consultation
Summary of government consultation, closing 11 June 2025.
Deputy editor of AT, Tim Fraser, discusses the newly formed society with its current chair, Chris Halligan MCIAT.
Barratt Lo-E passivhaus standard homes planned enmasse
With an initial 728 Lo-E homes across two sites and many more planned for the future.
Government urged to uphold Warm Homes commitment
ECA and industry bodies write to Government concerning its 13.2 billion Warm Homes manifesto commitment.
From project managers to rising stars, sustainability pioneers and more.
Places of Worship in Britain and Ireland, 1929-1990. Book review.
Comments
It did not help me at all shouldn't have wasted my time on ya.
Sorry to hear, have you checked out the related articles section.