This article's title contains conjecture and does not reflect any official material, as no official name for it is currently known to exist.
Double Track Bridge and Siding Runby is an area where a double-tracked bridge crosses over a triple-tracked line nearby a small siding. The location has no official placement on the Island of Sodor.
Once, whilst trying to get his photograph taken, Thomas overtook Percy by the signal box, surprising the latter and causing him to run into a pile of coal at the end of the siding. Thomas later came back to lift him out with Rocky.