A dumbwaiter is a small freight elevator or lift intended to carry food. Tom is attacked by the "13th Floor Elevator" above London and shoots it down. The entrance was via a bookcase which led to a secret elevator. This halves any building costs associated with elevator shaft doors. He pulls her off the ladder and onto the top of the elevator. A sidewalk elevator is a special type of freight elevator. It's also used by counterweights for lifting up an elevator, crane, or sash window. "Wasp" was the first carrier fitted with a deck-edge elevator for aircraft. It stabilises the condition of the air inside the elevator car. Phobos also could be a good counterweight for a space elevator. If successful, graphene could be used in the construction of a space elevator. A third elevator forward, , serviced the extended hangars. Safety testing of mine shaft elevator rails is routinely undertaken. Using this conditioned air in the elevator does not increase energy costs. There are many other uses for the construction elevator.