Another large contributing factor to the expense of running steam was the building, maintaining and operating of water purification equipment and the placement of water facilities along the right of way just to fill the tenders. Yea, I know you guys who live in the Northwest are saying Huh? What the heck are water purification plants? Our water up here is so pure, we can use it in the batteries in our vehicles. But there were railroads who operated in what were termed as "Bad Water Districts" near and in the deserts where using the local water supply would have scale build up in a boiler that would render the locomotive inoperative (the damn thing won't steam) in some cases, eight months. They couldn't get any heat transfer through the flues or sheets due to scale build up of alkaline,calcium and other minerals. Some railroads in the west had to "Washout" steam boilers every couple of months. I'm not a diesel fan but the only water you have in them is what is in the radiator and in the Igloo cooler in the cab. In todays operation I'm not sure if they use water in the radiators anymore. Some of you folks who run modern day diesels can tell us the mix of chemical coolant to water ratio if any.