During the 4449's run on the Louisiana World's Fair Daylight train in 1984, the Espee assigned both its' " Daylight " - painted diesels to the train for the run over Tehachapi. I have viewed video footage, taken by a friend, of the train rounding the horseshoe curve in the middle of Bealville siding, where 4449 started to bog down on the grade. You could see & hear the diesels throttle up to assist the train up the grade. Due to the steam - heated passenger equipment used, and the diesels' lack of steam lines, they were used on the point. This was quite upsetting to many foamers at the time, though the diesels proved useful as an advance warning of the trains' arrival later in the day, when Espee sent them ahead of the train for the rest of its' run into Los Angeles. BTW, though the 4449 is alive and well, both diesels are no longer around !!!
Further proof of the wisdom in assigning a diesel to a steam excursion is the diesel's use as a range extender, especially with the almost total lack of trackside water plugs nowadays. Even though most mainline steam excursions now feature an auxiliary tender for added water capacity, it is nice to have the option of throttling back the steamer and saving water. As Doyle McCormack mentioned to me last year in Tacoma, it takes a long time to fill a 10,000 gallon tender through a three - inch fire hose.
As an personal aside to " Juppo ", it seems as though you find fault with everything on this site. So, WHY ARE YOU HERE??? Perhaps you have been blocked from all the other railroad sites, due to your use of negative & foul language ??? Perhaps whomever tripped on the rock you live under, can drop it back on your head as a favor to the rest of us ???