The first 30 of Reading class G1sa Pacifics were built at the Reading shops from
1916-1922. The last five of this class were built by Baldwin in 1924. With
40,900 lbs starting te and 80 inch drivers, these were certainly not light
Pacifcs. They had a Wootten type firebox, designed for burning an anthracite waste
product, "culm", and anthracite coal in general. Similar Pacifics were to be
found on the Central New Jersey, the Lehigh Valley the Delaware, Lackawanna &
In 1948, Reading Shops built Class G3 (no more "s", just as on the Pennsy)) 210-219. Basically,
these were developments of a later version of 124, class G2sa. They had higher boiler pressure,
and such details as a Worthington SA feedwater heater and cast steel engine beds. Under the
combined onslaught of diesels and the debilitating effect of declining passenger traffic, they were
all gone within nine years. One of the places where they worked was on the Pennsylvania-
Reading Seashore Line, during the summer rush. Actually, on PRSL runs which served PRR 30th
Street, they may well have been the last steam locomotives to haul passenger trains in
Class G1-sa (Locobase 445)
Data from Railway Age Gazette (21 July 1916), pp 107-109. See also DeGolyer, Vol 74, pp. 89 + and RDG 11 - 1926 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection. Wooten type boiler
First Pacifics (five in the order) bought by the Philadelphia and Reading. RA's report commented that the valve gear and reciprocating parts had been made as light as possible to "reduce the ill effects from the counterbalancing." The piston load per pound of reciprocating parts was 79 lb (35.8 kg) and 65% of the reciprocating parts was balanced. The result was a dynamic augment of 41.5% of the static weight at 80 mph (129 kmh). Inside-admission piston valves measured 12" (306 mm) in diameter.
Used on the Boardwalk Flyer between Philadelphia and Atlantic City. Reading built 25, Baldwin the last five in a batch (works #57756-57760) in April 1924. Baldwin built another five in 1925 with 74" drivers; see Locobase 9411.
Class G1-sb (Locobase 9411)
Data from Reading 11 - 1926 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection. See also DeGolyer, Vol 74, pp. 102+. Works numbers were 58264-58266, 58291-58292 in March 1925.
Locobase 445 shows the lion's share of this design, the version that rolled on 80" (2,032 mm) drivers. To finish the class in 1925, the Reading bought five from Baldwin with smaller drivers. Otherwise they were repeats of the G1-sa down to the 12" (305 mm) inside-admission piston valves.
Class G2-sa (Locobase 158)
Data from tables in 1930 Locomotive Cyclopedia, supplemented by Reading 11 - 1926 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive collection.
Built 10 years after the first Pacifics on the Reading (Locobase 445), these Baldwins (works 59226, 59254-59258) differed only in small details. They were fitted with the large Wootten firebox fitted to most Reading engines. Westcott (1960) says these engines "were carefully designed so they could run as fast as the Reading's Atlantics". Used on the Boardwalk Flyer between Philadelphia and Atlantic City.