How to stop a free-falling elevator

[bfosler]

This is a different take on an elevator problem:

An elevator and contents have a mass of 300kg and travels at 2.5 m/s during normal operation. The elevator's cables break and begins to free-fall.

You need to stop the elevator and the max allowed deceleration is 4m/s^2. There is 0.05m between each side of the elevator and the walls, and the coefficient between steel members and the elevator shaft is mu(k)=0.3.

I assume that you can use steel wedges to help stop the elevator and then couple it with a spring mechanism at the bottom. But, it seems that even with 4 steel wedges on each side, the spring will need to create a force of ~500N.

Any suggestions...because I'm kinda all out of ideas

Thanks

 

[civil_dude]

It all depends on "when" you can apply your options. Is it immediately, or some?what? time before you can apply your options.

I would flood the bottom of the shaft myself. If you can get 10' of water, then you may only have a few broken legs.

 

[kyle8921]

for presenting this unique problem! As a scientist, my first suggestion would be to consider alternative solutions to stopping the elevator. While using steel wedges and a spring mechanism may work, it may also be a complex and time-consuming process.

One possible solution is to use a magnetic braking system. This involves installing powerful electromagnets on the walls of the elevator shaft. When the elevator falls, these magnets would create a magnetic field that would interact with the metal components of the elevator, generating a force that opposes the direction of motion, thus slowing down the elevator. This method has been used in high-speed trains and roller coasters and could be adapted for use in an elevator.

Another option to consider is using a parachute system. This would involve deploying a parachute from the top of the elevator shaft when the cables break. The parachute would create air resistance and slow down the elevator's descent. This method may also require less force from the spring mechanism, as the parachute would do most of the work in slowing down the elevator.

Additionally, implementing an emergency brake system in the elevator could also be a viable solution. This would involve installing a brake mechanism that can be activated in the event of an emergency. The brake could be designed to engage automatically when the elevator reaches a certain speed, thus slowing it down and bringing it to a stop.

Ultimately, the best solution will depend on various factors such as cost, feasibility, and safety. It may be beneficial to consult with engineers and experts in elevator technology to determine the most effective solution for this specific situation.