ATSF 3804 at Chester, MA. in 6/1979.

Santa Fe GP40X 3805 leads two sisters, the 3805 and 3806, on a westbound through Chester, MA. in late June, 1979. The prototypes for what would eventually become the GP50 tested on the B&A for several weeks in June and July of 1979. CR sent a like number of SD40's to the AT&SF as "collateral" during the test period.