The double crossover does not have to be there. Is there any reason why there can't be an open window in that wall above the crossover? The wall doesn't exist yet, so this would be a location for viewing.
In western Pennsylvania you wou;d have slow-moving iron ore unit trains running between Lake Erie and the steel mills in Pittsburgh.Also coal/cole for the furnaces. The Pittsburgh and Lake Erie operations would be a starting point. You also have the NYC and PRR to study.