Tank locomotiveA tank locomotive or tank engine is a steam locomotive that carries its water in one or more on-board water tanks, instead of a more traditional tender. Most tank engines also have bunkers (or fuel tanks) to hold fuel; in a tender-tank locomotive a tender holds some or all of the fuel, and may hold some water also. There are several different types of tank locomotive, distinguished by the position and style of the water tanks and fuel bunkers. The most common type has tanks mounted either side of the boiler.
LocomotiveA locomotive or engine is a rail transport vehicle that provides the motive power for a train. If a locomotive is capable of carrying a payload, it is usually rather referred to as a multiple unit, motor coach, railcar or power car; the use of these self-propelled vehicles is increasingly common for passenger trains, but rare for freight. Traditionally, locomotives pulled trains from the front. However, push-pull operation has become common, where the train may have a locomotive (or locomotives) at the front, at the rear, or at each end.
Diesel locomotiveA diesel locomotive is a type of railway locomotive in which the power source is a diesel engine. Several types of diesel locomotives have been developed, differing mainly in the means by which mechanical power is conveyed to the driving wheels. The most common are diesel-electric locomotives (usually faster, more powerful types of locomotives) and diesel-hydraulic (some shunting types). Early internal combustion locomotives and railcars used kerosene and gasoline as their fuel.
Baldwin Locomotive WorksBaldwin Locomotive Works (BLW) was an American manufacturer of railway locomotives from 1825 to 1951. Originally located in Philadelphia, Pennsylvania, it moved to nearby Eddystone in the early 20th century. The company was for decades the world's largest producer of steam locomotives, but struggled to compete when demand switched to diesel locomotives. Baldwin produced the last of its 70,000-plus locomotives in 1951, before merging with the Lima-Hamilton Corporation on September 11, 1951, to form the Baldwin-Lima-Hamilton Corporation.
Fairlie locomotiveA Fairlie locomotive is a type of articulated steam locomotive that has the driving wheels on bogies. The locomotive may be double-ended (a double Fairlie) or single ended (a single Fairlie). Fairlies are most famously associated with the Ffestiniog Railway in North Wales. While the Fairlie locomotives are now used only on heritage railways, the vast majority of diesel and electric locomotives in the world today follow a form not very different from the Fairlie — two power trucks with all axles driven, and many also follow the Fairlie's double-ended concept, capable of being driven equally well in both directions.
Electric locomotiveAn electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or on-board energy storage such as a battery or a supercapacitor. Locomotives with on-board fuelled prime movers, such as diesel engines or gas turbines, are classed as diesel-electric or gas turbine-electric and not as electric locomotives, because the electric generator/motor combination serves only as a power transmission system. Electric locomotives benefit from the high efficiency of electric motors, often above 90% (not including the inefficiency of generating the electricity).
Aerial refuelingAerial refueling, also referred to as air refueling, in-flight refueling (IFR), air-to-air refueling (AAR), and tanking, is the process of transferring aviation fuel from one aircraft (the tanker) to another (the receiver) while both aircraft are in flight. The two main refueling systems are probe-and-drogue, which is simpler to adapt to existing aircraft, and the flying boom, which offers faster fuel transfer, but requires a dedicated boom operator station.
Steam locomotiveA steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, oil or, rarely, wood) to heat water in the locomotive's boiler to the point where it becomes gaseous and its volume increases 1,700 times. Functionally, it is a steam engine on wheels. In most locomotives, the steam is admitted alternately to each end of its cylinders in which pistons are mechanically connected to the locomotive's main wheels.
Fireless locomotiveA fireless locomotive is a type of locomotive which uses reciprocating engines powered from a reservoir of compressed air or steam, which is filled at intervals from an external source. They offer advantages over conventional steam locomotives of lower cost per unit, cleanliness, and decreased risk from fire or boiler explosion; these are counterbalanced by the need for a source to refill the locomotive, and by the limited range afforded by the reservoir.
Integer programmingAn integer programming problem is a mathematical optimization or feasibility program in which some or all of the variables are restricted to be integers. In many settings the term refers to integer linear programming (ILP), in which the objective function and the constraints (other than the integer constraints) are linear. Integer programming is NP-complete. In particular, the special case of 0-1 integer linear programming, in which unknowns are binary, and only the restrictions must be satisfied, is one of Karp's 21 NP-complete problems.
