How Do Elevators Work? A Complete Guide

You press a button, a metal box arrives, you step in, you press another button, and a minute later you're 20 floors up. Somewhere behind the walls, a motor spins, steel cables pull, and a stack of iron plates drops to balance you out. That's the short version.

An elevator is a car attached to a lifting mechanism that moves up and down inside a vertical shaft, called a hoistway. Two common types are traction elevators, which use ropes or belts and a counterweight, and hydraulic elevators, which use pressurized oil and a piston.

Table of Contents

1. The Basic Parts of an Elevator
2. How Traction Elevators Work — Cables, Counterweights, and a Big Motor
3. Hydraulic Elevators: Simpler, Slower, Still Everywhere
4. Traction vs. Hydraulic — and Why the Choice Is Usually Obvious
5. The Machine Room Is Disappearing
6. What Keeps You Safe
7. From Button Press to Door Open
8. FAQ

The Basic Parts of an Elevator

Before getting into the two main types, here are the components they share. Hoistways and equipment spaces are for authorized personnel; passengers should not try to access them.

• Car: The enclosure you ride in. It sits on a steel frame called the sling, which connects to the lifting mechanism. The cab interior (the paneling, floor, and ceiling you see) is a separate structure mounted inside the sling — a box inside a box.
• Elevator shaft (hoistway): The vertical channel the car travels through. Guide rails keep the car aligned. Wiring, sensors, and — in traction systems — the counterweight all live in here too. It's more crowded than most people imagine.
• Elevator pit: A shallow space below the lowest floor, at the bottom of the hoistway. It houses the buffers, some wiring, and the bottom of the guide rails. Pits vary in depth depending on the system — hydraulic elevators often need deeper pits than traction.
• Drive system: The motor and machinery that move the car. In traditional setups this lives in a dedicated machine room. In newer designs it's inside the hoistway itself. More on that below.
• Controller: The brain. It processes hall calls and car calls, decides which direction to send the car, and coordinates with the drive system. Modern controllers are microprocessor-based. Older ones used relay logic — big panels full of electromechanical relays that sound like a chorus of clicking insects when they're running. Newer buildings may use destination dispatch systems, where passengers enter their floor number in the lobby and the system assigns them to a specific car — no car buttons needed.
• Doors: Two sets. The car doors travel with you. The landing doors (hoistway doors) stay on each floor. They're mechanically linked by a door coupler (a clutch or vane assembly) so they open and close together.
• Safety devices: Governors, brakes, buffers, door sensors. The reason the "elevator free-fall" scenario exists only in movies. Full breakdown below.

How Traction Elevators Work — Cables, Counterweights, and a Big Motor

Traction elevators are the workhorse. Mid-rise office building? Traction. Hospital? Traction. Anything taller than about six stories? Almost certainly traction.

Think of it like a seesaw. The elevator car hangs on one side of a set of steel cables (called hoist ropes), and a heavy counterweight hangs on the other. Both wrap over a grooved wheel — a sheave (essentially a pulley) — at the top of the hoistway. When the motor turns the sheave, friction between the cables and the grooves moves the car up and the counterweight down, or the reverse. That friction is where the name "traction" comes from.

The counterweight is a stack of cast iron or steel plates — typically equal to the weight of the empty car plus about 40% of the rated passenger load. That balance means the motor isn't fighting the full weight of the car and passengers — it's only overcoming the difference between the two sides. An empty car going up? The counterweight is heavier, so the motor barely works. A full car going up? Now the motor earns its keep. It's an efficiency trick that's been around since the earliest electric elevators, and it still works beautifully.

Geared vs. Gearless

Two sub-types here, and the distinction matters more than you'd think.

Geared traction puts a gearbox between the motor and the sheave. High-speed motor in, slow sheave rotation out. Common in buildings up to about 250 feet (roughly 20 stories). Speeds of 100–350 feet per minute. Less expensive to install, but the gearbox adds maintenance, noise, and energy loss. These are being phased out in new construction, though thousands are still in service.

Gearless traction skips the gearbox entirely — the motor connects directly to the sheave. Bigger motor, slower rotation, but the system is more efficient and significantly quieter. Speeds of 500 feet per minute and up. Every super-tall building in the world uses gearless machines. For new mid-rise construction, gearless with permanent magnet motors (compact, energy-efficient motors that don't need external power to maintain their magnetic field) has become the default, and for good reason.

Hydraulic Elevators: Simpler, Slower, Still Everywhere

Hydraulic elevators work on a principle you already understand if you've ever used a hydraulic car jack. A pump pushes pressurized oil into a cylinder (also called a jack). A piston extends and pushes the car up. To come back down, a valve releases the oil back to the reservoir and gravity handles the rest. No cables, no counterweight.

There are a few configurations, and which one you see depends a lot on when the building was built:

Conventional (in-ground) hydraulic: The cylinder is buried in a hole drilled below the pit, right under the car. The piston extends straight up. Travel is limited to the depth of the hole — usually 60 feet or less, so about six stories max. You still see plenty of these, but new installations are rare. Drilling the hole is expensive, and an underground steel cylinder sitting in soil and groundwater for 30 years creates exactly the environmental headache you'd expect.

Holeless hydraulic: Cylinders mounted above ground beside the car, with a roping arrangement to multiply the piston's travel. No hole, no underground corrosion risk. This is where most new low-rise hydraulic installations have landed.

Roped hydraulic: A hybrid — shorter piston with cables to extend the travel range. The piston pushes a sheave, the sheave pulls the cables, the cables move the car. Clever, but adds complexity.

Hydraulic elevators top out at about 75–150 feet per minute. Nobody's riding one to the 40th floor. But for a four-story apartment building or a warehouse with heavy freight, they're hard to beat on cost and simplicity.

Traction vs. Hydraulic — and Why the Choice Is Usually Obvious

In practice the building height usually decides it. Under six stories with no speed requirements? Hydraulic. Above that? Traction. There are edge cases — a three-story building owner who wants a premium ride, or a freight application where hydraulic's raw lifting power wins — but the edge cases are pretty narrow.

The Machine Room Is Disappearing

Traditional traction elevators need a dedicated machine room — a room at the top of the building (sometimes the bottom) that houses the motor, controller, and drive equipment. It takes up real square footage that architects and building owners would rather sell or rent.

Machine-room-less (MRL) elevators fix this. The hoisting machine — a compact permanent magnet motor — goes directly in the hoistway, usually at the top. The controller sits in a wall cabinet on the landing. The machine room is just... gone.

KONE's MonoSpace line was one of the first MRL platforms to see wide adoption, and at this point every major manufacturer offers one. For new construction in the low- to mid-rise range, MRL has essentially become the default. The space savings, energy efficiency, and installation speed all point the same direction.

But there's a trade-off that matters to the people who maintain these things. When the machine lives in the hoistway, you service it from the top of the car or from the landing — not from a room where you can spread out tools and stand upright. Ask a technician who's done a rope change on an MRL unit in a tight hoistway and you'll hear about it.

What Keeps You Safe

This is the section worth reading even if you skip everything else.

Elevators are one of the safest ways to move through a building. The fatality rate is extraordinarily low relative to the billions of trips taken per year in the U.S. alone (the numbers come from the National Elevator Industry, Inc. and the Bureau of Labor Statistics — and the majority of those fatalities involve maintenance workers, not passengers). This safety record isn't luck. It's a stack of redundant systems refined over 170 years, starting with Elisha Otis's safety brake demonstration at the 1854 Crystal Palace exhibition.

Governor and Safety Brake

A governor is a speed-monitoring device at the top of the hoistway, connected to the car by its own rope. If the car exceeds a preset overspeed threshold — the exact speed depends on the type of safety installed and the rated car speed, as specified in the ASME A17.1/CSA B44 code — the governor grabs its rope, which activates the safety brake on the car frame. Steel jaws clamp the guide rails. The car stops. Hard.

Overspeed and Slack Rope Detection

Long before the governor would ever trip, the controller is watching. Modern systems monitor car speed and rope tension continuously. If the car accelerates beyond normal parameters — even a little — the controller cuts motor power and engages the machine brake, an electromagnetic brake on the drive sheave.

Slack in the ropes? That could mean a snag, an obstruction, or something worse. The system catches it and stops. This is the first layer — fast, electronic, and almost always the one that actually intervenes in a real-world problem.

Door Interlocks

Every landing door has an interlock — an electromechanical lock that keeps the door shut unless the car is physically at that floor. And the car won't move unless every interlock on every floor confirms locked. It's a series circuit: one broken link kills the whole chain.

This is why elevator doors don't just pop open between floors. It's also why a faulty interlock on the third floor can shut down the entire elevator — the system doesn't know why the interlock is open, only that it is, and it won't take chances.

Buffers

Spring or oil-filled shock absorbers at the bottom of the elevator pit. If the car somehow travels past the lowest floor, the buffers absorb the energy. Spring buffers handle lower-speed elevators; oil buffers handle faster ones. Matching buffers sit under the counterweight too. They're the last physical barrier, and in a properly maintained elevator, they should never see real action.

The Layers Are the Point

These devices serve different protective functions. Their condition, maintenance, and testing matter; a general explanation of safety systems cannot establish that a particular elevator is safe to use.

From Button Press to Door Open

People sometimes ask what's actually happening in that 15–30 seconds between pressing the hall button and the doors opening. There's a lot going on behind the panels:

You press the hall call button. That signal hits the controller, which logs a call for your floor and direction. If the building has multiple elevators, a dispatching algorithm (the logic that decides which car answers which call) figures out which car to send — it's weighing distance, current direction, how many stops are already queued, and (on smarter systems) predicted traffic patterns. Buildings with a single elevator skip this; the car just goes.

The controller tells the drive system to move. On a traction elevator the motor spins up the sheave; on a hydraulic the pump starts pushing oil. Modern variable-frequency drives (VFDs) ramp the motor speed up and down smoothly — that's the gradual push you feel (or ideally don't) as the car starts and stops. Older systems without VFDs had noticeably jerkier starts. You'd know.

As the car approaches your floor, sensors in the hoistway feed position data to the controller. The system decelerates and levels the car — aligning the car floor with the landing floor so there's no step or gap at the threshold. Leveling accuracy matters more than people realize; bad leveling is a tripping hazard, especially for anyone using a wheelchair or cart.

The car door operator kicks in. It drives the car doors open, which pull the landing doors open through the door coupler. You step in, select your floor, and the whole cycle runs again.

From button press to doors open, figure 15–45 seconds depending on how far the car had to travel.

FAQ

Can an elevator fall if the cables break?

Elevator safety should not be reduced to a promise that a fall is impossible. Suspension components and protective systems need appropriate maintenance and inspection. If an elevator stops unexpectedly, follow the passenger guidance below rather than attempting to inspect or escape from it.

What happens if the power goes out?

If you are inside an elevator when it stops, use the alarm, intercom, or emergency telephone to request help. Stay clear of the doors and wait for qualified assistance. Otis advises passengers not to leave the cabin unless a qualified engineer or the fire brigade authorizes it.

Do not force the doors open or try to climb out. Otis’s passenger safety guidance explains what to do when an elevator stops between floors. Recovery arrangements depend on the equipment and building; do not assume the car will move or the doors will open automatically.

How often do they need maintenance?

Arrange maintenance around the equipment manufacturer’s instructions and the requirements of the authority responsible for the installation. Confirm the service plan with the maintenance provider and check local inspection and testing obligations separately. ASME A17.1/CSA B44 covers maintenance, inspection, and testing; the code edition and local rules applicable to the elevator must be checked.

Don't skip maintenance. Small problems compound.

How long do elevators last?

That depends on what you mean. The motor and car frame? 25–30 years, sometimes more. The controller, door operator, and cab interior? Those wear out faster. Most buildings hit a point around 15–25 years where a modernization makes sense — replacing the controls, drives, and fixtures while keeping the machine and rails. Full rip-and-replace happens around 30–40 years, but plenty of elevators are running well past that with good maintenance and a mod or two.

What's the deal with freight elevators?

Same core technology — traction or hydraulic — but built for punishment. Load ratings of 5,000–20,000 lbs or more. Wider openings with vertical-lift or bi-parting doors instead of the center-opening doors you're used to. Reinforced steel cabs — you won't find carpet or mirrors in here. They're classified by loading type under the ASME code (Class A through Class C3, ranging from general freight to heavy industrial truck loading), and the class affects everything from door timing to structural requirements.

How fast can they go?

A hydraulic elevator in a small apartment building might do 75 feet per minute — walking pace, basically. A standard mid-rise traction elevator runs 350–500 ft/min. The fastest elevators in the world, in super-tall buildings in Asia and the Middle East, exceed 3,000 ft/min — that's about 34 mph in a vertical shaft. At those speeds, pressurization systems in the cab manage the ear-popping effect, same idea as an airplane cabin.

Related Reading

• Elevator Glossary — Every term on this site, defined so it actually makes sense
• Types of Elevators — Traction, hydraulic, MRL, and the less common ones
• How to Become an Elevator Mechanic — What it takes, what it pays, and what the work is actually like
• Elevator Safety Systems Explained — Every device in the safety chain, in detail
• What Is Elevator Modernization? — When buildings upgrade, and what that involves