A number of factors came into play in the demise of steam. Labor costs were big as well as the fact that each locomotive was essentially hand made, there were no standardized parts. Having to maintain a large force of machinists,pipe fitters,and other specialized tradesmen as well as the facilities needed to complete their tasks was a huge expense. Having the ability to order a replacement part, take delivery of that part and install it without having to do ANYTHING to it to make it work was an enormous selling point for the diesel locomotive.

N&W made the last steam locomotives in North America using the most modern parts available . They were some of the most efficient and powerful engines ever built. N&W chose to continue with steam based on their access to coal as that was their biggest customer. Even with modern materials, those last few engines were still saddled with the main problems faced by ALL steam.

The materials used in operating a steam locomotive also contribute to its wear and tear. Water on steel causes rust. Coal and cinders cause erosion of flues. Heat causes steel to become soft,expansion and contraction cause steel to become brittle. Keeping an engine working requires continued attention and frequent maintenance.

There are some modern materials available now that might make a steam locomotive viable. The fact that you can burn just about anything to make steam makes it attractive in this time of high oil prices.Ceramics and composites can line the inside of a boiler for rust prevention. Automatic controls could essentially eliminate the need for a fireman. The issue of multiple unit operation for additional power when needed would need to be addressed.

Still, There are few locomotives around that can match the shear power that as steam locomotive can produce. If the costs can be mitigated and down time minimized, we may very well see the return of this most awesome form of railroading. Only time will tell.