Historical Photo Of The Month - September 2003

Spin Tank
Photograph Number 384-649A

This plexiglas test tank, as seen in the JPL Hydraulics Laboratory in 1947, imitated the 500 rpm stabilization spin of the BUMPER WAC high-altitude rocket. Engineers realized that the liquid fuel inside the rocket's tanks would be accelerated by the frictional drag of the rotating tank wall and centrifugal force would change the level of the liquid in different parts of the tank. In place of actual fuel, the tank used water to determine how a liquid would react to the rotation and whether the proposed fuel outlet location would work properly. This test produced photographs, film, and data to help engineers design an efficient fuel system.

In 1947, the Hydraulics Laboratory was located in the Quonset-style building 78, one of many buildings constructed when JPL worked under contract to the Army. This building no longer exists, but similar work is now done by the Propulsion and Fluid Systems Services Group (3573) in building 233.

For more information about spin tank tests, or about the history of JPL, please contact the JPL Archives. [JPL Progress Report No. 4-79, "Water Tests of a Full-Scale Spinning Model of the BUMPER WAC Propellant Tank" by Gilbert L. Bell and Robert F. Rose, July 13, 1949.]

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