Firefighting trains have been around for well over 100 years — the first ones were pulled by steam locomotives, but you rarely see them since they are used in remote areas near a fire that has limited access by the public. The apparatus usually consists of one or more tank cars that each hold more than 10,000 gallons of water and a high-volume pump that can support a master stream and additional hand-held hose lines.
The concept is to protect the railroad infrastructure, keeping the right of way open for trains. And sometimes the railroad will serve as a fire line — the application of water could keep the fire from crossing to the other side.
The videos below of a Union Pacific firefighting train were shot at the Delta Fire, the 63,000-acre blaze north of Redding, California. The first one is from ABC news, featuring fire photographer Dan Ryant. The one after that is raw footage shot by Mr. Ryant mostly from the top of the train.