Pennsylvania Railroad class GG1

The GG1 was 79 feet 6 inches (24.23 m) long and weighed 475,000 pounds (215,000 kg).[2] The frame of the locomotive was in two halves joined with a ball and socket joint, allowing the locomotive to negotiate sharper curves.[3] The body rested on the frame and was clad in welded steel plates. The control cabs were near the center of the locomotive on each side of the main oil-cooled transformer and oil-fired train-heating boiler. This arrangement, first used on the PRR's Modified P5 class, provided for greater crew safety in a collision and provided for bi-directional operation of the locomotive.[4] Using Whyte notation for steam locomotives, each frame is a 4-6-0 locomotive, which in the Pennsylvania Railroad classification system is a "G". The GG1 has two such frames back to back, 4-6-0+0-6-4. The related AAR wheel arrangement classification is 2-C+C-2. This means one frame mounted upon a set of two axles unpowered (the "2") and three axles powered (the "C") hinged with the ball and socket to another frame of the same design (the +). The unpowered "2" axles are at either end of the locomotive. The GG1 was equipped with Leslie A200 horn.

A pantograph on each end of the locomotive body was used to collect the 11,000 V, 25 Hz alternating current (AC) from the overhead lines. In operation the leading pantograph was usually kept lowered and the trailing raised to collect current, since if the rear pantograph failed it would not strike the forward pantograph. A transformer between the two cabs stepped down the 11,000 V to the voltages needed for the traction motors and other equipment.[4] Twelve 385-horsepower (287 kW) GEA-627-A1 traction motors (AC commutator motors, not AC induction motors[5]) drove the GG1's 57-inch (1,448 mm) diameter driving wheels on six axles using a quill drive. The power required was such that double traction motors were used, with two motors driving each axle. The traction motors were six-pole field, 400 volts, 25 Hz rated each at 385 hp (287 kW). The motors were frame-mounted using quill drives to the sprung driving wheels providing a flexible suspension system across a relatively long locomotive frame which allowed full wheel weight to rest on the rail for good traction regardless of track condition. A series wound commutator motor's speed is increased by increasing the applied voltage to the motor thus increasing the current through the motor's armature which is necessary for increasing its torque, thus increasing motor speed.[6][7] The engineer's cab had a 21 position controller for applying voltage to the motors. Four unpowered leading/trailing wheels were mounted on each end of the locomotive.

At the time of the GG1's introduction, railroad passenger cars required steam from the locomotive to operate heating equipment. The GG1 had an oil-fired steam generator to provide this steam to the train's "steam line."[8]

The first designer for the GG1 project was industrial designer Donald Roscoe Dohner, who produced initial scale styling models, although the completed prototype looked somewhat different.[20][21] At some point, PRR hired famed industrial designer Raymond Loewy to "enhance the GG1's aesthetics."[12][20] The final design is retrospectively 'Art Deco' as we know it today.

Although it was thought until 2009 that Loewy was solely responsible for the GG1's styling, Dohner is now understood to have contributed as well. (Dohner's GG1 designs influenced the modified P5as, which debuted before the GG1 — not, as was thought, the other way around.[21]) Loewy did claim that he recommended the use of a smooth, welded body instead of riveted one used in the prototype.[22] Loewy also added five gold pinstripes and a Brunswick green paint scheme.[22]

In 1952, the paint scheme was changed to Tuscan red; three years later, the pinstripes were simplified to a single stripe and large red keystones were added.[23]

On January 15, 1953, train 173, the overnight Federal from Boston, was approaching Washington behind GG1 4876. The train passed a signal 2.1 miles (3.4 km) north of Union Station between 60 and 70 miles per hour (97 and 113 km/h), and the engineer decreased the throttle and started applying the brakes.[24] When the engineer realized that the train was not slowing down, and applying the emergency brake had no effect, he sounded the engine's horn. A signalman, hearing the horn and noting the speed of the 4876, phoned ahead to the station master's office.[25] 4876 negotiated several switches without derailing, at speeds well over the safe speed limits and entered the station at around 35 to 40 miles per hour (56 to 64 km/h).[26] The train demolished the bumping post, continued through the station master's office and into the concourse[26] where it fell through the floor into the station's basement. Thanks to the evacuation of the concourse, there were no fatalities in the station, or aboard the train. A temporary floor was erected over the engine, and the hole it created, for the inauguration of President Dwight D. Eisenhower.[25] 4876 was eventually dismantled, removed from the basement and reassembled in Altoona. It survives in the B&O Railroad Museum in Baltimore.

The accident was determined to have been caused by a closed "angle cock", a valve on the front and rear of all locomotives and rail cars used in the train's airbrake system, on the rear of the third car in the train.[27] The handle of the angle cock had been improperly placed and had contacted the bottom of the car. Once it was closed the air brake pipe on all the cars behind the closed valve remained at full pressure, keeping the brakes released on those cars while the brakes on the locomotive and first three cars were applied in emergency.[28] This was the only major wreck involving a GG1 in the entirety of its 49-year career.

The only major electro-mechanical breakdown of the GG1 was caused by a blizzard which swept across the northeastern United States in February 1958.[29] The storm put nearly half of the GG1s out of commission. Exceptionally fine snow, caused by the extreme low temperatures, was able to pass through the traction motors' air filters and into the electrical components.[30] When the snow melted it short circuited the components.[30] On about 40 units, the air intakes were moved to a position under the pantographs.

Amtrak 904 westbound at Harrison, New Jersey in June 1975

In 1968 the PRR with its 119 surviving GG1s merged with the New York Central Railroad to form Penn Central. After its creation in 1971, Amtrak purchased 30 for $50,000 each, and[31] leased 21, of which 11 were for use on New York and Long Branch commuter trains.[32] Amtrak renumbered the purchased GG1s #900–929 as a solid block, later renumbered with a prefix "4". The leased units with conflicting numbers were then renumbered 4930–4939, except 4935 which kept its old PRR/PC number.

Amtrak attempted to replace the GG1s in 1975 with the General Electric E60,[33] but they were not a success: a 102-mile-per-hour (164 km/h) derailment during testing had to be investigated (the E60 used the same trucks as the P30CH diesel then in service with Amtrak), which delayed acceptance, and the hoped-for 120 miles per hour (193 km/h) service speed was never achieved (timetable limit was 90 mph, then 80, then 90).

It was not until Amtrak imported two lightweight European locomotives – X995, an Rc4a built by ASEA of Sweden and X996, a French design – that a replacement was found. The ASEA design, initially nicknamed the "Swedish swifty",[34] or the "Mighty Mouse"[35]—and later referred to often as the "Swedish Meatball"—was the winning design. Electro-Motive Diesel, then a part of General Motors, was licensed to build it and it became the basis of the AEM-7.[34] With AEM-7s on hand, Amtrak finally replaced its GG1s. GG1 service on Amtrak ended on April 26, 1980.[36]

Penn Central went bankrupt in 1970 and its freight operations were later assumed by government-controlled Conrail, which used 68 GG1s in freight service until the end of electric traction in 1980.

The last GG1s in use were some of the 13 assigned to New Jersey Transit (#4872–4884) for its North Jersey Coast Line between New York and South Amboy (the former New York and Long Branch) that ran until October 29, 1983, thus retiring the locomotive after 49 years of service.[37]