Conrail EMD SD40 Nos. 6280 and 6277 helper locomotives are on the rear of an eastbound freight, assisting with braking on the Allegheny Mountain crossing west of Altoona, Pennsylvania, on October 21, 1988. The train is rolling through famous Horseshoe Curve, and besides helping the train downgrade, it’s a convenient way to get the helper units back to Altoona for another push.