Reading 4-6-2 "Pacific" Type Locomotives

Class G1-sa (Locobase 445)

Wooten type boiler

First Pacifics (5 in the order) bought by the Philadelphia and Reading. Railway Age Gazette (21 July 1916, 107-109) 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 and 65% of the reciprocating parts was balanced. The result was a dynamic augment of 41.5% of the static weight at 80 mph.

Used on the Boardwalk Flyer between Philadelphia and Atlantic City. Reading built 25, Baldwin the last 5 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.

Locobase 445 shows the lion's share of this design, the version that rolled on 80" drivers. To finish the class in 1925, the Reading bought 5 from Baldwin with smaller drivers. These were produced in March 1925 (works #58264-58266, 58291-58292).

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.

Specifications
Class	G1-sa	G1-sb	G2-sa
Locobase ID	445	9411	158
Railroad	Reading	Reading	Reading
Whyte	4-6-2	4-6-2	4-6-2
Road Numbers	105-134	200-204	175-179
Gauge	Std	Std	Std
Builder	several	several	Baldwin
Year	1916	1925	1926
Valve Gear	Walschaert	Walschaert	Walschaert
	Locomotive Length and Weight
Driver Wheelbase	13.83'	13.83'	13.83'
Engine Wheelbase	35.58'	35.58'	35.92'
Ratio of driving wheelbase to overall engine wheebase	0.39	0.39	0.39
Overall Wheelbase (engine & tender)	67.98'	67.98'	72.20'
Axle Loading (Maximum Weight per Axle)	61000 lbs	59120 lbs	64860 lbs
Weight on Drivers	176900 lbs	177210 lbs	192540 lbs
Engine Weight	273600 lbs	288120 lbs	306360 lbs
Tender Light Weight	160000 lbs	183000 lbs	154000 lbs
Total Engine and Tender Weight	433600 lbs	471120 lbs	460360 lbs
Tender Water Capacity	8000 gals	9000 gals	9000 gals
Tender Fuel Capacity (oil/coal)	12.9 tons	16 tons	15 tons
Minimum weight per yard of rail on which locomotive could run	98.28 lb rail	98.45 lb rail	106.97 lb rail
	Geometry Relating to Tractive Effort
Driver Diameter	80"	74"	80"
Boiler Pressure	220 psi	220 psi	230 psi
Cylinders (dia x stroke)	25" x 28"	25" x 28"	25" x 28"
Tractive Effort	40906 lbs	44223 lbs	42766 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort)	4.32	4.01	4.50
	Heating Ability
Firebox Area	282 sq. ft	282 sq. ft	314 sq. ft
Grate Area	94.50 sq. ft	94.50 sq. ft	95 sq. ft
Evaporative Heating Surface	2926	2926	3045
Superheating Surface	652	652	745
Combined Heating Surface	3578	3578	3790
Evaporative Heating Surface/Cylinder Volume	183.93	183.93	191.41
	Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation	20790	20790	21850
Same as above plus superheater percentage	24578.45	24578.45	26145.05
Same as above but substitute firebox area for grate area	73345.22	73345.22	86416.28
Power L1	18815.58	17404.41	21822.21
Power MT	703.47	649.57	749.61