A pair of light engines head south toward a stranded train on the Shoreline Sub. Earlier this morning, the northbound train experienced DPU air compressor trouble - the train went into emergency twice, on Mequon Road, and in Port Washington. The original crew eventually made it as far north as Mink Ranch Road. They secured the rear half of the train and continued to Sheboygan with two units and the first half of the train. After spotting the cars at the power plant, they were relieved by a fresh crew. Seen here, the relief crew heads south to tie onto the second bunch of cars.