Customers wishing to visit the vault must first board one of the rickety carts at the rear of the bank. This cart then takes them on a journey through the various chambers of the bank, including the main vault.
After leaving the main bank chamber, the cart rounds a wide corner on the edge of a ravine next to the bank. Scary spider webs and skeletons line the opposite wall (not easy to see in this shot).
Finally, the cart reaches the main vault chamber. Here the customer can deposit or withdraw valuables and cash. A computerized system automatically transports the customers valuables into the "vault" at the correct time. In fact, the real "vault" is far underground and is accessible to only bank employees and transport machinery. A robotic Professor Dumbledore is available to chat or collect customers' mortgage payments.
On the way back from the vault, the cart again turns a corner near another ravine. Then, the cart safely returns to the station at the back of the bank.
The cart ride is constructed using a standard Technic chain driven by several large Technic gears. The chain is stretched into a large rectangle by 4 main gears at each corner. Two additional gears provide support in the middle of the long sections. A micro-motor is attached to one of the gears to power the ride. The speed is a bit slow, but seems pretty consistent with scale speed as one might encounter on a "dark ride" at an amusement park.
The cart is attached to the chain using a few links of larger chain elements (from an old Expert Builder bulldozer set) bound to a 1x4 plate. The plate is attached to a 1x1x1 brick with a stud on the side (to flip directions 90 degrees) and then two 1x1x1 round bricks are used to support the cart above the "floor." The mechanism is a tad fragile and does require occasional maintenance. Therefore, as seen in the picture, panels at the back of the bank can be removed to properly re-attach the cart when it occasionally derails.