The idea of the long double drill track approach, is that any freight loco on the main line can either push or pull drop-ooffs or pick-ups without having to tie up the mainline. The double track approach (rather than a ladder), makes use of double-slip switches and Ys within the yard, and allows the switcher access to any of the 7 tracks within the yard, without going on the mainline.The switcher works from within the yard, to assemble 10-15 car consists, and places them on the drill tracks for pick-up.