rocklkp.blogg.se - Cajon pass railworks america

Lawrence Hill, Engineer on helper unit 7443 (age 42).

Allan Riess,† Brakeman on 3rd locomotive (age 43).

The crew that was called for train 7551 East were as follows: Train and helper crews of Southern Pacific 7551 East It was composited by an SD40T-2, two SD45Rs, and an SD45T-2 on the head end, an SD40T-2 and SD45R on the helper end, and 69 hopper cars loaded with trona. The train catapulted from the 35 mph curve next to Duffy Street, scattering locomotives and cars, as well as lading. Once dynamic braking had been defeated by the helper engineer's emergency brake application the enormous weight of the heavily loaded cars caused rapid acceleration that could not be resisted solely by mechanical braking.

The combination of weight miscalculation, poor communication and faulty brake equipment resulted in a total train weight that was too great to adequately control on the down grade. It was also determined after the wreck that the engineer operating the helper locomotives knew of the faulty dynamic brakes on one of his units, but did not communicate that information to the head end crew. Upon retrieving the locomotives' "black boxes" (event recorders) and the recorded data therein, it was discovered that the third head end locomotive's dynamic brakes were not functioning at all, although the sound of the cooling fans misled crews into believing dynamic braking was functional. The train reached a speed of about 100 miles per hour (160 km/h) before derailing on an elevated 35 miles per hour (56 km/h) curve next to Duffy Street, sending the head end locomotives and several cars off the high railroad bed and into houses on the street below, completely demolishing them. When the helper engineer realized that the train speed was not being adequately controlled, he made an emergency brake application, which deactivated dynamic braking, resulting in a runaway condition.

Hence there was not enough dynamic braking force available to maintain control of train speed during the descent. Clerks in Mojave had miscalculated the weight of the train, while the engineer and crew at the head end were unaware that one of the rear helper engines had inoperative dynamic brakes. Seven houses on the street immediately next to the tracks were demolished by the wreck, as were the lead locomotives and all of the freight cars. The conductor, head-end brakeman, and two residents were killed in the wreck.