Union Pacific's Big Boy

[@kaho1545]

The video was shot beautifully😊

[@jockellis]

Are all those diesels working or deadheading?

[@billwatkins276]

In the past, the UP crew has said that the diesels are sometimes used to help stretch the Big Boy's boiler fuel and water supplies in areas where there may not be an adequate or appropriate (mineral content) water supply or opportunities to stop for refueling / rewatering. (They had big problems with running low on water while crossing Louisianna a few years ago.) There are also critical places on the system where the railroad wants the assurance that they have backup power in the consist in case of mechanical problems on the steam locomotive. In the past few years, Big Boy also needed a diesel in the consist that could comply with the new Federal requirements for Positive Train Control devices. UP upgraded the Big Boy recently so that it is now self-compliant with the Positive Train Control requirements so they're able to make some trips without the diesels now. With respect to stops for fuel and water, rail plant "rationalization" has resulted in there not being as many suitable sidings or second mainline tracks available any longer where they can stop without seriously disrupting mainline revenue traffic. The UP steam program has always been very careful about minimizing or not disrupting the work of the operations departments and staying on those departments' "good" sides as much as possible. Some have suggested that frequent disruptions of revenue traffic was one of the factors that killed Norfolk Southern's very popular steam program.