[886]

hand brakes were applied, but only to the first 5 lead cars only. the engineer also used air brake, but it lost its pneumatic pressure after the engine got shut off.

"Though exhausted after the journey, Mr. Harding took the laborious step of setting the mechanical hand brakes — a train’s version of an automobile parking brake — on the five lead locomotives, an equipment car and an empty boxcar.

That was the first big mistake. Investigators calculated that Mr. Harding should have also secured the hand brakes on 18 to 26 of the tank cars before retiring to his hotel."