WEll, tenders were one of the most obviose bases, although Niagaras had an overhang to fit on turntables. They also had more coal, since they had water troughs.
The Niagara, S-1b PT tender held 48 tons of coal. Whereas the UP FEF-2 PT tender only held 25 tons. On the other hand the Niagara S-1b tender held 18,000 gallons, but the FEF-2 tender held 23,500 gallons. Jim, I found two sites that summarize the S-1b and FEF-2 specifications. http://www.steamlocomotive.com/northern/nyc.shtml http://www.steamlocomotive.com/northern/up.shtml
