# How does the prison gate work?

In the episode 30 Days Without Accidents Michonne returns and Rick opens the gate. But what kind of pulley mechanisms can make that work? Especially when you don't have electric motors like the garage door.

I can understand the gate from the castle where you use gravity. To raise and lower the gate. But here you have two doors, one to the left and one going to the right with the same rope? And then how do you reverse the process to close it?

I imagine if you have something like a bicycle gear you can place a vertical pole and rotate on both direction, but then you need two chains (one for each door) and a very long chain to connect to the main gate. And how do you make it strong enough so walkers don't break the pole, hold that big door, and also smooth enough to rotate it remotely.

• `But what kind of pulley mechanisms can make that work? Especially when you don't have electric motors like the garage door.` How does the absence of electric motors somehow (further) invalidate using pulleys? Electric motors merely generate kinetic energy, which anyone with a rope can do as well. Oct 31, 2018 at 12:17
• @Flater my question was `what kind pulley` You need convert that kinetic energy on angular momemtun. And the gates have to move on diferent direction. In the picture you can see there are 4 ropes on floor 2 left 2 right. But he only move the ropes on one side., Nov 1, 2018 at 14:36