Shore durometer B, C, D, DO, E, M, O, OO, OOO, OOO-S, and R. Each scale results in a value between 0 and 100, with higher values indicating a harder material. Durometer, like many other hardness tests, measures the depth of an indentation in the material created by a given force on a standardized presser foot. This depth is dependent on the hardness of the material, its viscoelastic properties, the shape of the presser foot, and the duration of the test. ASTM D2240 durometers allows for a measurement of the initial hardness, or the indentation hardness after a given period of time.
Chicago North Shore and Milwaukee Railroad 1979. The outbreak of World War II caused the railroads of the United States to see a sharp rise in traffic. Even before the imposition of rationing of fuel and rubber made auto travel difficult, the North Shore saw its freight and passenger traffic rise to record levels, in part due to the railroad serving important military facilities: the Army's Fort Sheridan just north of Highwood, and the Navy's Great Lakes Naval Training Station, just south of North Chicago. North Shore saw its traffic increase to the extent that the railroad was forced to borrow equipment from the Chicago Rapid