A timing chest or valve chest is a compartment on an internal or external combustion engine (e.g. gasoline or steam engine) which provides access to the tappets and valves. The chest is fitted with an inspection cover sealed with a gasket.
A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be transformed by a connecting rod and crank into rotational force for work. The term "steam engine" is most commonly applied to reciprocating engines as just described, although some authorities have also referred to the steam turbine and devices such as Hero's aeolipile as "steam engines". The essential feature of steam engines is that they are external combustion engines, where the working fluid is separated from the combustion products. The ideal thermodynamic cycle used to analyze this process is called the Rankine cycle. In general usage, the term steam engine can refer to either complete steam plants, such as railway steam locomotives and portable engines, or may refer to the piston or turbine machinery alone, as in the beam engine and stationary steam engine.
A four-strokeengine is an internal combustion (IC) engine in which the piston completes four separate strokes while turning the crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either direction. The four separate strokes are termed:
Main components found on a typical steam locomotive include:
An overhead valve engine, abbreviated (OHV) and sometimes called a pushrod engine, is a piston engine whose valves are located in the cylinder head above the combustion chamber. This contrasts with flathead engines, where the valves were located below the combustion chamber in the engine block.
A multi-valve or multivalve engine is one where each cylinder has more than two valves. A multi-valve engine has better breathing, and with more smaller valves may be able to operate at higher revolutions per minute (RPM) than a two-valve engine, delivering more power.
The GWR 4100 Class was a class of steam locomotives in the Great Western Railway (GWR) of the United Kingdom.
A Corliss steam engine is a steam engine, fitted with rotary valves and with variable valve timing patented in 1849, invented by and named after the US engineer George Henry Corliss of Providence, Rhode Island. Corliss assumed the original invention from Frederick Ellsworth Sickels, who held the patent (1829) in the US patent office.
A valvetrain is a mechanical system that controls the operation of the intake and exhaust valves in an internal combustion engine. The intake valves control the flow of air/fuel mixture into the combustion chamber, while the exhaust valves control the flow of spent exhaust gases out of the combustion chamber once combustion is completed.
A throttle is a mechanism by which fluid flow is managed by construction or obstruction.
The Dean Single, 3031 Class, or Achilles Class was a type of steam locomotive built by the British Great Western Railway between 1891 and 1899. They were designed by William Dean for passenger work. The first 30 members of the class were built as 2-2-2s of the 3001 Class.
The cylinder is the power-producing element of the steam engine powering a steam locomotive. The cylinder is made pressure-tight with end covers and a piston; a valve distributes the steam to the ends of the cylinder. Cylinders were initially cast iron, but later made of steel. The cylinder casting includes other features such as valve ports and mounting feet. The last big American locomotives incorporated the cylinders as part of huge one-piece steel castings that were the main frame of the locomotive. Renewable wearing surfaces were needed inside the cylinders and provided by cast-iron bushings.
Piston valves are one form of valve used to control the flow of steam within a steam engine or locomotive. They control the admission of steam into the cylinders and its subsequent exhausting, enabling a locomotive to move under its own power. The valve consists of two piston heads on a common spindle moving inside a steam chest, which is essentially a mini-cylinder located either above or below the main cylinders of the locomotive.
A snifting valve is an automatic anti-vacuum valve used in a steam locomotive when coasting. The word Snift imitates the sound made by the valve.
The South African Railways Class 5B 4-6-2 of 1904 was a steam locomotive from the pre-Union era in the Cape of Good Hope.
The South African Railways Class Experimental 2 2-8-0 of 1902 was a steam locomotive from the pre-Union era in the Cape of Good Hope.
The South African Railways Class MA 2-6-6-0 of 1909 was a steam locomotive from the pre-Union era in the Natal Colony.
The South African Railways Class MH 2-6-6-2 of 1915 was an articulated Mallet-design steam locomotive.
The South African Railways Class GA 2-6-0+0-6-2 of 1921 was an articulated steam locomotive.
The Trofimoff valve is a springless pressure-compensation piston valve for steam locomotives.
A cataract was a speed governing device used for early single-acting beam engines, particularly atmospheric engines and Cornish engines. It was a kind of water clock.