Sky Ride

Infobox Bridge
bridge_name=
official_name=Century of Progress Exhibition Sky-Ride
locale=Chicago, Illinois
carries=fairgoers in suspended 36 passenger cars
crosses=Century of Progress exhibition grounds, downtown Chicago
open=February 2, 1933
closed=November, 1934
design=Transporter Bridge
mainspan= 1850 ft (564 m) (some sources say 2000 ft)
length=3200 ft (975 m) including 2 600 ft (182 m) backstays
clearance=628 ft (160 m)high towers
below=190 ft (58 m) above fairgrounds
lat=41.861954
long=-87.605066

The Sky Ride was a transporter bridge designed by Robinson & Steinman and built for the Century of Progress Exposition (or World's Fair) in Chicago, Illinois (located near what became Meigs Field) in 1933. After the run of the fair concluded, it was demolished in November 1934. It had an 1,850-foot (564-meter) span. Suspended from it, 215 feet (66 meters) above the ground, were 10 (or 12, sources differ) cars, each carrying 36 passengers.

The transporter bridge [Transporter bridges are so called because they transport payloads across rather than providing a roadway. Thus, they can be made in different ways. The Duluth Aerial Lift Bridge had two towers with a truss connecting them at the top for the tracked carriage vehicle to travel on, with the suspended payload carrier at ground level. The Sky Ride's towers were cable stayed (with backstays) and apparently did not have a truss connecting them. The illustration of the skyride at night, shown in the information box gives the impression there is a truss at the 200 foot level, and Structurae.de reports it as being a deck truss cable-stayed bridge but the panoramic illustration suggests that the apparent truss is really only a web of cables from which the car tracks are suspended.] is much more common in Europe. In the United States, only two transporter bridges were ever built: the Aerial Lift Bridge [Due to capacity constraints, the Duluth bridge was converted from a transporter bridge to a more conventional vertical lift bridge with a raisable through truss span in 1930. Thus, the count of transporter bridges extant in the US never exceeded 1, and after November 1934, stands at zero again.] in Duluth, Minnesota in 1905, and the Sky Ride.

History

The Century of Progress Exposition committee reportedly sought an exciting "signature" attraction, one that would span the grounds but be relatively cheap to build. The ride was built in the span of 6 months prior to the fair's opening, by a consortium of 5 companies: Great Lakes Dredge and Dock Company, Inland Steel, John Roebling and Sons, Mississippi Valley Structural Steel and Otis Elevator at a cost of about 1,000,000 USD.

It consisted of two towers, each 628 feet high, spaced 1850 feet apart. Each tower had 4 elevators with a 30 person capacity. Fair goers could take a trip across from one tower to the other at the 200 foot level, or take the elevator farther up to the observation decks [There were two decks per tower and Bausch and Lomb supplied the 12 coin-operated telescopes on the tower observation decks.] at the top of the tower. If they chose to take a trip across, they rode in one of 12 double-decked "Rocket Cars" carried across from one tower to the other. Each car emitted steam intended to resemble a "tail" or rocket exhaust, as it traveled across the wires. At night, lights were focused on the cars as they traveled between the towers, and lights were also attached to the bottom of the elevators.

The ride had a capacity of 5,000 people per hour. It was reported that the attraction had 2,616,389 riders in 1933 and a total of about 4.5 million during the course of the fair. At the time of construction the span between towers was one of the longest in the world, allegedly exceeded in span only by the George Washington Bridge, and the towers were higher than any of the skyscrapers then extant in Chicago. It was reported that it contained 2,000 tons of steel, 100 miles of cabling and that the cableway had a breaking strength of 220,000 pounds per square inch.

At the conclusion of the fair the Sky Ride was demolished using dynamite on one tower and a charge of thermite packed around the base of the other.

Brochure

The following brochure text [Brochure text is taken from the "Official Guide Book Of The Fair, 1933", Published by A Century Of Progress, Sourced from this [http://www.geocities.com/Heartland/Pointe/8431/skyride.html Geocities] page.] gives a feel for the breathless prose of the day.

Notes

Further reading

*Fernández Troyano, Leonardo (1999) Tierra sobre el agua, Colegio de Ingenieros de Caminos, Canales y Puertos, Madrid (Spain) , ISBN 84-380-0148-3, 1999; pp. 755.
*Kretschmer, Winfried Geschichte der Weltausstellungen (1st edition), Campus-Verlag, Frankfurt (Germany) , ISBN 3-593-36273-2, 1999; pp. 192.
*Ratigan, William (1959) Highways Over Broad Waters, Wm. B. Eerdmans Publishing Company; pp. 224-227. ASIN B0007IY0OC

External links

Reference materials

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* [http://www.geocities.com/Heartland/Pointe/8431/skyride.html Geocities page] with medallions, text from the CoP guidebook, and a postcard image of the Sky Ride at night
* [http://www.niederelbe.de/FAEHRE/chicago.htm niederelbe.de] Skyride information (in German)
* [http://www.earthstation9.com/index.html?1933_chi.htm Earth Station 9] many facts and figures taken from this source (but corroborated at other sources)
* [http://www.niederelbe.de/FAEHRE/f-international.htm niederelb.de international] Transporter bridge information, see also the Transporter bridge article.
* [http://www.chipublib.org/008subject/012special/cop.html Chicago Public Library ] Century of Progress materials

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* [http://www.bridgepix.com/bridgeblog/?p=26 BridgePix.com blog entry showing colored postcard view]
* [http://lcweb2.loc.gov/pnp/pan/6a28000/6a28300/6a28300r.jpgLibrary of congress panorama] taken by Harry Koss; August 22, 1933.
* [http://lcweb2.loc.gov/pnp/pan/6a27000/6a27900/6a27920r.jpgLibrary of congress panorama] taken by Harry Koss; October 30, 1933.
* [http://www.niederelbe.de/FAEHRE/chic-map.jpgPostcard image] from niederelbe.de