The G5s turned out to be the heaviest and most powerful 4-6-0 class locomotive ever built. Construction started in 1923 and by 1929 the G5s was the only 4-6-0 on the PRR. Ninety of these locomotives were produced by the Juniata shops between the years of 1923 and 1925 for use on Pennsylvania Railroad lines. Thirty-one were built for the Long Island RR with larger tenders, which were similar to those commonly used on the PRR K4s locomotives.
The boilers of the G5s were almost the same as those used on the E6 4-4-2s and H10 2-8-0s. All were built with superheaters and power reverse gear, but never got feedwater heaters or stokers, and thus were hand fired.
Fast-accelerating locomotives for commuter service, they were rough-riding at high rates of speed, and brutish machines, the largest, heaviest and most powerful 4-6-0s built in America. The locomotive was built mainly for the milk business and passenger service was rare.
The Max Gray model is basically well constructed and accurate. After repairing some problems with the engine, I replaced or added a number of detail castings, piping, and other parts, and added my unique loco-to-tender hoses. The oversize flanges were ground down and the drivers were then re-plated, and brake hangers were mounted on the frame. The drive was improved with a NWSL can motor, ball and cup universal, PFM gearbox, and a new drawbar and wiring. The nicely detailed Sunset tender and accurate Bowser trucks capped this Pennsy project locomotive. I still may add a diode drop headllite bulb.
'Model Railroader Cyclopedia Vol. 1 - Steam Locomotives' (Kalmbach)
'Pennsylvania Railroad 1940s - 1950s' by Don Ball