Duke University Medical Center Patient Rapid Transit or Personnel Rapid Transit (PRT) was an automated people mover system located at the Duke University Medical Center in North Carolina, in the United States. The system was in operation from 1979 to 2009, and service is now discontinued. The PRT was notable for having cars propelled by a linear induction motor

Linear induction motor

A linear induction motor is an AC asynchronous linear motor that works by the same general principles as other induction motors but which has been designed to directly produce motion in a straight line....

 and suspended on a bed of compressed air similar to a hovercraft

Hovercraft

A hovercraft is a craft capable of traveling over surfaces while supported by a cushion of slow moving, high-pressure air which is ejected against the surface below and contained within a "skirt." Although supported by air, a hovercraft is not considered an aircraft.Hovercraft are used throughout...

. Uniquely, the cars could move sidewards, as well as backwards and forwards.

The proclaimed "horizontal elevator

Elevator

An elevator is a type of vertical transport equipment that efficiently moves people or goods between floors of a building, vessel or other structures...

" system was designed by Otis Elevator Company

Otis Elevator Company

The Otis Elevator Company is the world's largest manufacturer of vertical transportation systems today, principally focusing on elevators and escalators...

 during the 1970s, installed beginning in 1977 and opened on December 8, 1979. The people mover was provided with three driverless Otis Hovair

Otis Hovair

Otis Hovair Transit Systems is a type of Hovertrain that replaces conventional steel wheels with hovercraft lift pads, and the conventional railway bed with a paved road-like surface, known as the "track" or "guideway". The concept aims to eliminate rolling resistance and allow very high...

vehicles which have a hinged-window at each end for emergency exit

Emergency exit

An emergency exit in a structure is a special exit for emergencies such as a fire: the combined use of regular and special exits allows for faster evacuation, while it also provides an alternative if the route to the regular exit is blocked by fire, etc....

.

The concrete guideway was built as double track

Double track

A double track railway usually involves running one track in each direction, compared to a single track railway where trains in both directions share the same track.- Overview :...

, connecting the three stations at Duke South, Duke North and Parking Garage II via a tunnel under Erwin Road.

Decommissioning

The 0.25-mile (<400 m) section between Duke South and Duke North was closed permanently on October 15, 2008 to allow for expansion of the hospital buildings.

The remaining section connecting Duke Parking Garage II with Duke North Hospital was closed at the end of 2008—2009 . The doorway for the station at Parking Garage II was permanently boarded up and turned into a wall. The leftover tracks and infrastructure remain.

Technology

The Hovair

Otis Hovair

Otis Hovair Transit Systems is a type of Hovertrain that replaces conventional steel wheels with hovercraft lift pads, and the conventional railway bed with a paved road-like surface, known as the "track" or "guideway". The concept aims to eliminate rolling resistance and allow very high...

 technology has been installed around the world. Later variants have used the same air-cushion technology, but propelled the vehicles by wire cable, such as at the Getty Center

Getty Center

The Getty Center, in Brentwood, Los Angeles, California, is a campus for cultural institutions founded by oilman J. Paul Getty. The $1.3 billion center, which opened on December 16, 1997, is also well known for its architecture, gardens, and views overlooking Los Angeles...

in Los Angeles.