Elevators: A Comprehensive Guide to Their Mechanics, Types, and Safety

0.000000    6.000000     Welcome to everyday explained your daily 20-minute dive into the fascinating house and wise of the world around you.
6.000000    11.000000     I'm your host, Chris, and I'm excited to help you discover something new. Let's get started.
11.000000    20.000000     Okay, let's jump into this. Think about your day. How many elevator rides? Maybe more than you even realize.
20.000000    24.000000     Easily. You step in, push a button, doors closed, doors open, done.
24.000000    32.000000     Right. But get this. The national elevator industry says US elevators make something like 18 billion trips a year. Billion.
32.000000    42.000000     Whoa, that's hard to even picture. Exactly. They're everywhere, totally essential for, you know, how we build sins now. But we barely think about them.
42.000000    48.000000     It's true. It's like this invisible workhorse. You interact with it constantly, but you don't really see the engineering behind it. It feels almost like magic.
48.000000    62.000000     Totally. Walk in a box, end up somewhere else, poof. But behind that feeling, there's just this incredible mix of physics, clever mechanics, safety engineering, refined over what 150 years.
62.000000    67.000000     Absolutely. And that's what we're doing in this deep dive. We're going to use these sources we've gathered to, you know, pull back the curtain a bit.
67.000000    72.000000     Yeah, look under the hood. How do they actually move? What's this crucial part we never see? How are they kept so safe?
72.000000    81.000000     We'll look at different types of why they're used. How tech still changing things. You've written tons of elevators, right? But let's figure out what's really going on when you travel between floors.
81.000000    94.000000     You might look at that next ride a little differently. Oh, I think you definitely will. The basics seem simple. Sure. But when you understand the why, like the counterweight or the sheer number of backup safety systems, yeah, it really clicks.
94.000000    106.000000     Okay. So let's start right there. The basics. What's actually making that cargo up and down? Okay. So at its most fundamental level, you've got the car. That's the box you ride in. Right.
106.000000    113.000000     Then there's the power source, usually an electric motor. And then the system connecting them cables, maybe bolts and pulleys.
113.000000    121.000000     So the motor's job is the motor typically up in a machine room provides the turning force. It rotates a big grooved wheel called a sheave.
121.000000    134.000000     S-H-E-A-V-E. Ah, sheave. Okay. And the cables run over that. Exactly. The cables or sometimes special belts now are attached to the car, loop over the sheave. And well, we'll get to the other end in a second.
134.000000    142.000000     The motor turns the sheave. The cables move. The car moves. Simple enough. Well, mostly the motor often uses gears too. That helps control the speed smoothly.
142.000000    153.000000     So you get that gentle start and stop. Not a sudden jerk. Right. You definitely notice when it's not smooth and speeds a big factor. Yeah. Residential lifts feel way slower than office tower ones.
153.000000    161.000000     Oh, huge difference. It's all about design and capacity. High rises need speed. Lots of people. Long distances. A small apartment building.
161.000000    173.000000     Slower is fine. Less demand. Okay. Motor, sheave, cables, car moves. Seems straight forward. But you mentioned something else. There's this really clever part that makes it all work better. Right. The counterweight.
173.000000    184.000000     Ah, yes. The counterweight. Absolutely. The unsung hero of the typical traction elevators. Basically a big, heavy block, steel, concrete, whatever. Okay. Where is it?
184.000000    192.000000     It's in the shaft, too, connected to the other end of those same cables that lift the car. And here's the key thing. It moves in the opposite direction to the car.
192.000000    201.000000     So car goes up. Canary goes down. Exactly. And it's heavy. It's weighted to be above the same as the car. Plus roughly half the weight of the passengers. It's designed to carry.
201.000000    213.000000     Half the passengers. Why half? Think of it like balancing a seesaw. If it balanced the empty car exactly, the motor would have to lift all the passengers. If it balanced a full car, the motor would struggle to lift an empty one.
213.000000    222.000000     Balancing the car plus half the load minimizes the maximum difference the motor ever has to handle. Whether going up or down, full or empty.
222.000000    237.000000     Ah, okay. That makes sense. It minimizes the effort needed. Precisely. It dramatically cuts down the work the motor has to do. Instead of hoisting the full weight of a loaded car, the motor just needs enough power to overcome the difference in weight between the car side and the counterweight side.
237.000000    249.000000     That must make a huge difference in how much energy it uses. A colossal difference. That's a key point in the sources. Without it, you'd need a much, much bigger motor, like a simple crane. With it, you just nudge the balance.
249.000000    261.000000     The sources mentioned typical motor power is maybe 5 to 15 kilowatts. That efficiency. It's largely down to the counterweight. Wow. Serious energy savings built right in. And I think you mentioned it helps the cables too.
261.000000    272.000000     Yeah, less net load means less strain on the cables, makes them last longer as a safety margin. And it makes breaking easier too. The brakes aren't fighting the full weight of the car, just the imbalance.
272.000000    289.000000     It's really quite elegant. I saw a mention of duplex counterweightless elevators. Is that different? That's an interesting variation yet. Instead of one car and one counterweight, you have two cars and connected shafts. They move opposite each other. So car A going up helps balance car B going down.
289.000000    297.000000     So they act as each other's counterweight. Essentially, yes. Another way to get that balancing effect without needing a separate dead weight. Clever stuff.
297.000000    307.000000     Really is. Okay. So that counterweight system is key for traction elevators, the kind we see in Paul buildings, but not all elevators are like that, right? Different buildings, different tech.
307.000000    317.000000     Absolutely. You use the right tool for the job. Traction is great for heightened speed, but other systems are better suited for other situations. The sources cover a few main types.
317.000000    328.000000     Like hydraulic elevators. You see those in like three or four story buildings, a lot. Right. Hydraulic systems use fluid pressure. There's a motor. But instead of turning a sheath, it powers a pump.
328.000000    337.000000     Out pump. Yeah. Pump pushes hydraulic oil into a cylinder. Inside the cylinder is a ram. Basically a big piston that piston pushes the car up.
337.000000    352.000000     So it's pushed up from below or the side. It can be either direct acting systems have the ram right underneath the car. Indirect acting systems might have the ram off to the side connected to the car via ropes and pullies. Strangely enough.
352.000000    361.000000     And they're mostly for lower buildings. Generally, yes. They don't usually have the speed or the height capability of traction systems. But for low rise, they have advantages.
361.000000    371.000000     Simpler design, sometimes easier installation, maybe, can mean a smaller machine room. But energy wise, you mentioned the counterweight saves energy for traction. Do hydraulics have that?
371.000000    378.000000     Typically, no. That's a key drawback mentioned in the sources. Most traditional hydraulic designs don't use a counterweight.
378.000000    386.000000     So the pump has to do all the work of lifting the car and its load against gravity. That usually means higher energy consumption compared to a balanced traction system.
386.000000    391.000000     Though some newer hydraulic designs do incorporate counterweights trying to get some of that efficiency back.
391.000000    401.000000     Interesting trade offs. Okay, simpler, maybe, but potentially uses more power. What about a pneumatic elevators using air? That sounds futuristic.
401.000000    406.000000     It does. Yeah, pneumatic elevators are pretty neat, often used in homes. They work by air pressure differences.
406.000000    414.000000     Imagine the car inside a sealed vertical tube. A system at the top, usually vacuum pumps, removes air from above the car.
414.000000    419.000000     The normal air pressure below the car then pushes it up into that low pressure area.
419.000000    430.000000     So you're lifted by a vacuum? Kind of, yeah. Lowering is just letting air back in carefully. The sources point out they're quiet, pretty energy efficient, and don't need all the mechanical bits like cables or hydraulic rams.
430.000000    440.000000     Plus, they often have those cool round glass designs, panoramic views from your home lift. That would be question experience. Okay, one more type mention, screw driven lifts.
440.000000    449.000000     Right, another one often found in residential settings. These use, well, a big screw. There's a long threaded steel column, the screw running up the shaft.
449.000000    457.000000     A motor, often attached to the car itself, turns a drive nut that moves along this screw. So the car literally climbs up the screw thread.
457.000000    463.000000     That's the idea. Motor turns the nut. The nut climbs the screw. The car goes up or reverses to go down.
463.000000    475.000000     The big advantages highlighted are that they're very space efficient. No machine room needed, no pit below usually, no counterweight space, very quiet too, and often easier to install in an existing home.
475.000000    485.000000     Amazing how many ways there are to solve the same problem, moving people vertically. But okay, with any of these systems, lifting people hundreds of feet. Safety has to be absolutely number one.
485.000000    496.000000     It is the paramount consideration. And you can talk about elevator safety without mentioning a Lysha Graves Otis. Back in the mid 1800s, lifts or hoists were dangerous if the rope broke.
496.000000    506.000000     Well, that was it. Gravity wins. Right. But Otis in 1861 technically, though he demoed it earlier, invented the safety elevator, not just a lift, a safe lift.
506.000000    520.000000     His invention is genuinely would allow architects to start thinking vertically, building skyscrapers. His demo at the Crystal Palace Expo, cutting the rope, legendary stuff. But how did that first safety break actually work? What was that mechanism?
520.000000    529.000000     It was brilliantly simple, according to the sources. His elevator car ran between vertical guide rails. These rails had teeth like a ratchet.
529.000000    543.000000     On the top of the car, he had these spring-loaded hooks or poles. Normally the tension from the lifting rope held these poles away from the teeth, pulled them in. But if that rope went slack, if it broke, the spring would instantly snap the poles outward.
543.000000    552.000000     And they'd bite into the teeth on the rails. Exactly. Jam right into them, stopping the car almost immediately. It was a purely mechanical backup. Fail safe, genius for its time.
552.000000    565.000000     A total game changer. And obviously modern elevators have built massively on that concept. Multiple safety layers now. Oh, absolutely. Today's elevators have layer upon layer of redundancy. It's far beyond just that one mechanical catch.
565.000000    578.000000     Like the brakes themselves are more advanced. Yes. Modern safety brakes are heavy-duty systems. They engage not just on cable failure, but for other issues to power loss, sudden stops, going too fast.
578.000000    588.000000     And they usually work by clamping down hard on the actual guide rails, bringing the car to a smooth controlled stop. And there's something to stop at going too fast in the first place.
588.000000    595.000000     That's the overspeed governor. It's a separate system. Could be mechanical. Could be electro-mechanical. It constantly watches the elevator speed.
595.000000    605.000000     Like a little speedometer? Sort of. Yeah. If the car exceeds a preset safe speed, the governor trips. Usually has these weights that fly outwards with centrifugal force.
605.000000    613.000000     That trip then activates the main safety brakes we just talked about. Stop the car now. Vital backup and the cables. You don't just rely on one, right?
613.000000    624.000000     Definitely not. Elevators use multiple steel cables, each made of many strands of wire. Each individual cable is strong enough to hold the car on its own. Usually several times over. They have huge safety factors.
624.000000    632.000000     So if one somehow failed, which is incredibly rare, given inspections, the others would easily hold the load.
632.000000    642.000000     The sources mentioned that Chicago incident at the former John Hancock Center. One cable broke, apparently made a loud noise, scared people badly, but the other six cables held.
642.000000    650.000000     The safety systems worked. Car descended slowly. Everyone was rescued safely. A real world test, unfortunately, but approved the redundancy works.
650.000000    654.000000     That's incredibly reassuring. What about the doors? People worry about getting caught.
654.000000    665.000000     Door safety is huge. You've seen those light beams, right? Yeah. That's often a light curtain. Multiple beams creating a safety net. If anything breaks those beams, a hand, a bag, anything that doors won't close or they'll reopen.
665.000000    678.000000     Plus their physical sensors too. And crucially, door interlocks. These are electro-mechanical locks that ensure the car cannot, absolutely cannot move unless all doors are fully closed and locked, prevents people falling into the shaft.
678.000000    681.000000     Okay. That's a lot already. Any other safety layers?
681.000000    688.000000     The sources list quite a few more overload sensors. The elevator won't move if it's too heavy. So you see those capacity signs. Right. Weight limits.
688.000000    699.000000     Emergency stop button inside the car. Emergency communication. A phone or intercom to call for help. Some home lifts have automatic shut-offs and power outages. Child locks even.
699.000000    706.000000     Depending on the type, things like special valves for hydraulics, chain protection, and way down at the bottom of the shaft. What's down there?
706.000000    718.000000     Buffers. Big springs or hydraulic shock absorbers. They're the absolute last resort. If somehow everything else failed and the car descended too fast, the buffers are there to cushion the impact.
718.000000    723.000000     Wow. Safety net after safety net after safety net. And for fires.
723.000000    733.000000     Yes, firefighter service, a critical feature. It's a special mode usually activated by key switch that lets firefighters take direct control of the elevator by passing all normal calls.
733.000000    742.000000     Essential for them to move gear or rescue people safely during a fire. Okay. With all that built in, it really does make you feel secure. The sources do mention potential hazards though.
742.000000    755.000000     They do, but it's crucial context. They list things like entrapment, getting stuck, often door related, overloading, break issues, electrical faults, structural problems, power failures during storms.
755.000000    764.000000     Even human error, like sticking a hand out, these are potential risks. But the whole point of the systems we discovered is to prevent those or handle them if they happen.
764.000000    772.000000     Exactly. That's why the source is stressed that elevators are statistically incredibly safe because of all those systems and because of required maintenance.
772.000000    781.000000     The hazards exist in theory, but the engineering is designed to make failures that cause injury extremely rare, provided the elevators properly maintained.
781.000000    787.000000     Which brings us neatly to maintenance and rules. All this tech is great, but only if it's kept working.
787.000000    796.000000     Absolutely fundamental. Regular professional maintenance is not optional. It's essential. The sources generally suggest maintenance checks by qualified technicians every six months or so.
796.000000    803.000000     And then formal inspections, often yearly, usually mandated by law. What do they actually check during maintenance?
803.000000    821.000000     It's pretty thorough. Cables, pulleys, brakes, obviously critical, control system, the brain, the motor itself, the car structure, counterweight, guide rails, doors and all their safety sensors and interlocks, electrical wiring, lubrication, replacing parts that show where.
821.000000    826.000000     And crucially, testing those safety systems, the governing, the brakes to make sure they will work if needed.
826.000000    834.000000     So inspections aren't just looking, they're testing too. Yes, and spotting potential problems before they become actual failures. That's the goal. Make sense.
834.000000    849.000000     And beyond the mechanics, what else falls under upkeep? Signage is important, as mentioned. Clear instructions, capacity limits, emergency numbers, who to call if it breaks down. Also, clear signs and barriers if it's out of service. Don't want anyone trying to use a broken lift.
849.000000    861.000000     And security sometimes plays a role. It can, yeah, access control systems, key cards, fobs, especially in offices or apartment buildings, limits access for security, but also ties into managing elevator use effectively.
861.000000    863.000000     And this is all governed by strict rules.
863.000000    882.000000     Oh yes, very heavily regulated. In the US, the big one is the ASME A17.1 safety code for elevators and escalators. It sets detailed standards for design, installation, operation, inspection, testing, maintenance, everything. Plus, state local codes often add more requirements.
882.000000    895.000000     Following these codes is mandatory for building owners and operators. That's good to know there's such a strong framework. Okay, let's circle back to energy. We talked about the counterweight saving a lot. Our elevators generally, energy hogs are fairly efficient.
895.000000    906.000000     For what they do, moving hundreds of thousands of pounds vertically, they're actually quite efficient, especially traction elevators with counterweights. That balancing act makes a massive difference.
906.000000    920.000000     Sources say elevators might only account for like 2 to 10% of a large building's total energy use. That's less than I might have guessed. Yeah, and certainly less energy than everyone taking the stairs. Plus, good maintenance keeps them running efficiently, preventing wasted energy.
920.000000    927.000000     And technology is making them even better on that front. Definitely. There's some really cool advancements. One big one is regenerative braking.
927.000000    949.000000     For generative, like in electric cars, exactly the same principle. When heavy cars going down or a light car is going up, the motor actually acts like a generator. Instead of the counterweight, doing all the work and maybe needing braking, the system captures that gravitational energy. And what does it do with it feeds it back into the building's electrical system or sometimes stores it in batteries.
949.000000    961.000000     So the elevator can actually generate power during parts of its cycle really helps overall efficiency. That's fantastic. What else is new or coming? Lots of focus on passenger experience and building integration.
961.000000    975.000000     Touchless controls using gestures or apps became big for hygiene, obviously. Destination dispatch systems are smarter. You enter your floor before getting in and it groups people going to the same floors into the same car. Fewer stops faster trips.
975.000000    986.000000     I've seen those less milk run stopping at every floor. Right. And deep integration with building management systems. Maybe AI optimizing traffic flow in the future. It's getting smarter.
986.000000    1003.000000     And for home elevators. Any specific tech trends there? Yeah, the sources note they've really evolved beyond just being functional. Design is huge now. Seamless integration into the home style, glass panels, sleek materials, quieter operation is always improving. Plus enhanced accessibility features.
1003.000000    1013.000000     They're seen more as a convenience and even a luxury feature that adds value to a home. So a far cry from just a basic lift. Definitely more refined and integrated now.
1013.000000    1031.000000     Well, this has been a fascinating deep dive. We've covered the core mechanics, the genius of that counterweight, the different types for different jobs, the incredible safety layers starting way back with Otis, the vital role of upkeep and rules and how tech keeps pushing things forward.
1031.000000    1040.000000     They really are these hidden pillars of modern life, aren't they? You barely notice them, but our vertical world depends entirely on these complex, safe, efficient machines.
1040.000000    1048.000000     Absolutely. Hopefully for everyone listening, this gives you a totally new appreciation next time you step into an elevator. It's so much more than just a box going up and down.
1048.000000    1057.000000     It really is. And you know, think about their history from simple ancient hoists to today's smart systems. It makes you wonder, doesn't it?
1057.000000    1073.000000     Well, how will the next generation of elevators continue to shape our buildings or cities? If vertical transport gets even faster, smarter, maybe uses magnetic levitation like some concepts explore, what new kinds of architecture or urban living does that make possible?
1073.000000    1080.000000     That's a great question, a truly vertical future enabled by ever evolving lifts, something to definitely think about on your next ride.
1080.000000    1094.000000     And that wraps up today's episode of Everyday Explained. We love making sense of the world around you five days a week. If you enjoyed today's deep dive, consider subscribing so you don't miss out on our next discovery. I'm Chris, and I'll catch you in the next one.