Zanesville & Western's 8599, with builders number 5676, was the last of a series of 200 SW1's delivered originally to the Pennsylvania Railroad in April, 1948 and was built at the shops in LaGrange, Ill.  It was originally numbered 5999 by the PRR, but later renumbered 8599 by the Penn Central.  During the fourteen year SW1 production, run changes and improvements took place increasing reliability, easing maintenance and modifying external appearances, including sealed-beam headlights and flat-top cab windows.

Zanesville & Western's 8599 had undergone a number of changes before being obtained.  Her original friction bearing trucks were replaced with roller bearings, increasing reliability.  Her single "glow" head and rear lights were replaced with dual 32 volt sealed beams and associated dimming resistor network.  And, her air compressor lubrication system was modified such that it obtains continuous lubrication from the prime movers lube-oil system eliminating the need to check the compressor crankcase oil level.  Little else has been changed since 1948.  After her 25 year dedication to Buckeye Central she will now become ZWSR's prime motive power.  The historic ZWSX 8599 carries on today as a true reminder of American diesel-electric locomotive production in its infancy.