So being the bored 16 year old railfan I am, I started thinking about this after talking to a friend who is an N&W Transition-Era modeler (HO) and N&W Steam fan. After looking at some of the steam engines designed and built late into the steam era (especially the J Class), I thought what if one was built new today?
This is just a hypothetical question that I'm curious about. What is a rough estimate of the cost to build an oil-fired 4-8-4 new from a scratch design that can meet/exceed Amtrak's requirements for certification? This would be a traditional styled steam engine and not like the ACE 3000 or something like that. The 4-8-4 would have 72"-80" drivers, have roller bearings everywhere possible (for ease of use and maintenance, definitely roller bearings on all tender axles), be easy to service, incorporate modern technology where possible such as an in-cab diesel m.u. control stand, lightweight (but strong) side rods, good counterbalancing, electronic speedometer, cab signaling and electronic speed limit HUD, good tractive effort, at least 5000 horsepower, 300 psi working pressure, and a self-lubrication system. Streamlining could also be incorporated to improve speed, but it adds weight. However, from what I understand (please correct me if I'm wrong), more weight on the drivers improves tractive effort and adhesion. The locomotive would be geared for high speed and high power output, somewhat of a scratch-built and scratch-designed cross between a Niagara and an N&W J Class. Please note this is only for a single 4-8-4 and not multiple or the feasibility of steam making a comeback. I'm sure all of us know steam will never come back. UP and Strasburg steam is the only steam we'll ever really see in revenue freight service.
Other suggestions would be helpful. Again this is just hypothetical and I know Tornado was something between 3,000,000 GBP and 5,000,000 GBP, so I'd imagine a 4-8-4 would be a bit more. As discovered later in the thread, a 4-4-4-4 T1 built from the ground up costs about $10,000,000 ($13,000,000 if the tender was built from the ground up). I know pretty much anything is possible so long as you have the cash to do it.
Hot Water, if you're reading this, I'll admit I don't know a huge amount about steam, so if there's anything useful you want to mention or educate me on please go right ahead.