What Does Big Boy 4014 Do at Night?

The Union Pacific Big Boy 4014 coming into the Steam Shop on 7-9-2021. 4014 came back from the test run to Denver and arrived well after dark. Only about 3 of us railfans stayed on the bridge for a few hours watching the crew put the equipment away, and perform the usual maintenance on the engine. The crew was still working when we left just shy of 1 am on 7-10-23.

[@ajizetio]

Very2 good and perfect.👍

[@1chuck96]

At 10:01 in, does anybody know what type of oil does she burn? As I understand it, back in the day the Steamers used "Bunker C" oil, (of which I have ZERO idea of ANYTHING related to oil),, but in today's world, I've heard that the light pacific in FL burns "spent" deep fryer oil and when she passes, it smells like a large order of Fries. If such is the case, and in theory, couldn't any oil burner use any kind of oil, (regular motor oil included)? Your thoughts?

[@railgraphix]

They use recycled motor oil from Gebro.