PRR S2
The S2 of the Pennsylvania Railroad was the most powerful steam locomotive ever built. The locomotive with number 6200 was produced in 1944 by the Baldwin Locomotive Works and was scrapped in 1953 again.
History
Mid-1930s were the Pennsylvania Railroad attention to the development of the steam locomotives. In particular, the success of the locomotive No. 6202 of the London, Midland and Scottish Railway aroused their interest. Therefore, the engineers of the railway company developed together with the turbine manufacturer Westinghouse Electric and Manufacturing Co. and Baldwin own concept for a steam locomotive with mechanical transmission. The engineers promised thereby a better efficiency and a lower structural weight than that of the electric power transmission. First, the conversion of an existing locomotive had been planned. Since the cost of this measure corresponded to almost the cost of a new building, has been waived. The designs were completed in 1941. Due to the war entry of the United States into the Second World War and the associated bottlenecks of light materials again led to a redesign.
The locomotive was built by the Baldwin Locomotive Works in September 1944. The testing was carried out on the route between Chicago and Crestline both freight and heavy express trains. The machine had excellent running properties and high Drawbar tractive.
Put to the test a maximum output of 4568 kW ( 6206 hp) was determined at 121 km / h. During test runs, the locomotives could pull a 17 -car train over a distance of 48 km at a speed of 169 km / h. At a speed of 106 km / h and a power of 3680 hp was achieved with 7.7% of the best overall efficiency. The tensile force of the locomotive exceeded all comparable steam and diesel locomotives (the latter at speeds over 64 km / h). Steam consumption in the latter was less than other locomotives at speeds above 48 km / h. At start up and at low speeds, the steam consumption was however strongly about it. So it happened that when starting up the boiler pressure could fall below 14 bar.
Through this highly variable boiler load, there was frequent studs fractures.
In August 1949, arrived at the locomotive to a heavy turbine damage. Since the maintenance costs rose steadily, the S2 was finally shut down in Crestline and Altoona. In 1952 she was finally decommissioned and scrapped the following year.
Design features
The design of the exhaust steam locomotive S2 broadly in a conventional steam locomotive. In place of the reciprocating steam engine, however, the steam turbine was located. The Belpaire boiler was provided with a combustion chamber and a mechanical feed grate ( stoker ). The hourly coal consumption was some 2 tons. It was built in a feedwater heater of the type Worthington.
The turbine engine kit, which was based on a turbine for marine propulsion, was located between the second and third coupled axle. The main turbine was on the right and one Rangierturbine with 1500 hp for the reverse drive on the left side of the locomotive. The Rangierturbine was designed for speeds up to 35 km / h and was turned on by means of a hydraulic clutch at standstill of the machine system. Through a monitoring system was ensured that the main turbine could be approached only when the Rangierturbine.
The turbine set was a closed system with downstream transmission. The turbine was a maximum speed of 9000 revolutions per minute. The transmission was a Westinghouse spring actuator to the second and third coupled axle. The gear ratio was 18,5:1. The other driving axles were driven by means of connecting rods.
The vapor was passed from the vapor collection box via the four control valves in the steam turbine. In the steam turbine, the vapor pressure of 21.8 bar reduced to 1.05 bar. This vapor was then passed over four blowing tubes in the chimney.
The frame was a steel casting. All axle and coupling rod bearings were designed as a roller bearing. Due to wartime restrictions on the use of lightweight metal compounds three axes had to be placed in the wheel bogies instead of two. In a major study in 1947 the locomotive smoke deflectors received. Two air pumps for the brake system have been disposed on the two sides of the smoke chamber. Below the smoke chamber to the locomotive front sat a large cooler for the compressed air.
The tender of the locomotive was originally made for a locomotive of class I1 labeled 180 -F -82. Later he was assigned as 180 -P -75 Class K4's No. 3768. For use with No. 6200 the tender was again rebuilt and was given the designation P- 180 - 85th He had two bogies with four axes.