There were also Lionel trains which were used to move radioactive materials in a hospital and were featured in an article in the June 1949 issue of Model Railroader (pp.16) The train was called the "Radium Train" and it began operation March 8,1949 at the Cleveland Clinic in Cleveland, Ohio. It shuttled radon between the supply room and the lab.
Interestingly enough, a large framed picture of one of the technicians loading the train was featured on a wall in one of the hallways of the hospital up until a remodeling about ten years back.
