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 Philadelphia.
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.
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 and wide Wootten fireboxes in a conventional-cab layout. The combustion chamber contributed 78 sq ft (7.25 sq m) to firebox heating surface area.
Original tender coal capacity was 15 tons. The entire class added brick arch and arch tubes and a Standard MB automatic stoker. 204 was later equipped with thermic syphons.
Built ten years after the first Pacifics on the Reading (Locobase 445), these Baldwins differed only in small details. They were fitted with the large Wootten firebox fitted to most Reading engines and gained another 80 sq ft (7.43 sq m) from the combustion chamber. 12" (305 mm) piston valves supplied the cylinders.
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. 178 was semi-streamlined in September 1936.
Locobase hasn't pinned down an explanation for why the Reading built ten new Pacifics at a time when the trend was strongly toward diesel power. But the railroad needed passenger power and its youngest 4-6-2s were over twenty years and hard used. So it took the basic power dimensions and wide Wootten firebox, put 80" drivers under a cast steel frame, juiced the boiler so it would withstand a high operating pressure, and added a Worthington 5A feed water heater.
The shops also adopted a pair of Boxpok disc drivers for the center coupled axle. The thread mentioned above consisted of a question about why and a couple of reasons offered. "Charlie 9" noted the high boiler pressure, which increased strain on the main driver, as well as the need to balance the main rod's effect. "Overmod" agreed, but added" "It's not just the added strength in the main driver, it's the added space for both the principal and the angled balance mass for low augment at high speed, and better seating and securement in the wheel for the main pins.".
Like all of the late-model North American steam locomotives, the G3s enjoyed relatively brief careers before being supplanted by diesels. Some were leased to the Pennsylvania-Reading Seashore Lines, where they hauled main-line commuter trains between Atlantic City and Philadelphia.
The official retirement dates for all ten fell in June 1957.
|Specifications by Steve Llanso of Sweat House Media|
|Railroad||Philadelphia & Reading||Philadelphia & Reading||Philadelphia & Reading||Philadelphia & Reading|
|Number in Class||30||5||5||10|
|Locomotive Length and Weight|
|Driver Wheelbase (ft / m)||13.83 / 4.22||13.83 / 4.22||13.83 / 4.22||13.83 / 4.22|
|Engine Wheelbase (ft / m)||35.58 / 10.84||35.58 / 10.84||35.92 / 10.95||36.58 / 11.15|
|Ratio of driving wheelbase to overall engine wheebase||0.39||0.39||0.39||0.38|
|Overall Wheelbase (engine & tender) (ft / m)||67.98 / 20.72||67.98 / 20.72||72.20 / 22.01||78.31 / 23.87|
|Axle Loading (Maximum Weight per Axle) (lbs / kg)||61,000 / 27,669||59,120 / 26,816||64,860 / 29,420|
|Weight on Drivers (lbs / kg)||176,900 / 80,241||177,210 / 80,381||192,540 / 87,335||197,184 / 89,441|
|Engine Weight (lbs / kg)||273,600 / 124,103||288,120 / 130,689||306,360 / 138,963||329,450 / 148,075|
|Tender Loaded Weight (lbs / kg)||160,000 / 72,575||183,000 / 83,008||154,000 / 69,853||257,540 / 116,818|
|Total Engine and Tender Weight (lbs / kg)||433,600 / 196,678||471,120 / 213,697||460,360 / 208,816||586,990 / 264,893|
|Tender Water Capacity (gals / ML)||8000 / 30.30||9000 / 34.09||9000 / 34.09||12,500 / 47.35|
|Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)||12.90 / 11.70||16 / 14.50||15 / 13.60||19 / 17.30|
|Minimum weight of rail (calculated) (lb/yd / kg/m)||98 / 49||98 / 49||107 / 53.50||110 / 55|
|Geometry Relating to Tractive Effort|
|Driver Diameter (in / mm)||80 / 2032||74 / 1880||80 / 2032||80 / 2032|
|Boiler Pressure (psi / kPa)||220 / 15.20||220 / 15.20||230.60 / 15.90||260 / 17.90|
|High Pressure Cylinders (dia x stroke) (in / mm)||25" x 28" / 635x711||25" x 28" / 635x711||25" x 28" / 635x711||25" x 28" / 635x711|
|Tractive Effort (lbs / kg)||40,906 / 18554.67||44,223 / 20059.24||42,877 / 19448.70||48,344 / 21928.50|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||4.32||4.01||4.49||4.08|
|Firebox Area (sq ft / m2)||282 / 26.21||282 / 26.21||314 / 29.18||431 / 40.04|
|Grate Area (sq ft / m2)||94.50 / 8.78||94.50 / 8.78||95 / 8.83||95 / 8.83|
|Evaporative Heating Surface (sq ft / m2)||2926 / 271.93||2926 / 271.93||3045 / 282.99||2981 / 276.94|
|Superheating Surface (sq ft / m2)||652 / 60.59||652 / 60.59||745 / 69.24||770 / 71.53|
|Combined Heating Surface (sq ft / m2)||3578 / 332.52||3578 / 332.52||3790 / 352.23||3751 / 348.47|
|Evaporative Heating Surface/Cylinder Volume||183.93||183.93||191.41||187.39|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||20,790||20,790||21,907||24,700|
|Same as above plus superheater percentage||24,532||24,532||26,288||29,887|
|Same as above but substitute firebox area for grate area||73,207||73,207||86,890||135,593|