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Glossary

Okay, so I am very "into" the Technical jargon. Perhaps you aren't. That doesn't mean you cannot enjoy these pages. I will give you a little bit to go on, here, in terms of what weird and wonderful stuff I am talking about.

Articulated Locomotive: A locomotive built with two separate engines under one long boiler and cab. They were articulated, or hinged, flexing between the two engines on curves. See also Mallet.

Bark: See also blast nozzle: This is the "Chuff chuff" sound you hear when a steam locomotive passes.

Blast Nozzle: Steam locomotives exhaust their spent steam through a nozzle pointed up the smokestack, to pull a draught on the fire. Like fanning a fire with a bellows, this makes it burn hotter, giving more heat and making more steam. They also use a blower, a steam jet up the stack to increase the draught when the engine is not running. Prior to getting steam up in a boiler, the blower is also a modified vacuum cleaner placed on the stack to pull a draught.

Blind Drivers: In order to get around sharp curves, some longer six- and eight-coupled locomotives (and more) had the flanges removed from one or more middle sets of wheels, so that the wheels did not bind up on the rails in the curves.

Boiler: A sealed tank for water, with surfaces heated by fire, used to produce steam at high pressure. The boiler fittings also offer ways to control steam into various purposes on the locomotive - running the engine, generating heat in coaches, electricity for the lights, and pumping air for the train brakes.

Bypass valve: Live Steam locomotives often have a continuous water pump driven on the axle. To control the amount of water entering the boiler, (which must be equal to the amount being used) there is a bypass valve on a return line to the tank. Open bypass means all water goes to the tank, and closed sends all water into the boiler.

Columbia, Mogul, Decapod: The Whyte Locomotive Classification system. Locomotives have different arrangements of leading guide wheels, large driving wheels, and small trailing wheels, depending on what type of work they are intended to do. Each different arrangement was given a name, to avoid awkward series' of numbers such as 2-4-2, 2-6-0, and 2-10-0.

Compound: A steam engine which uses its' steam two or more times. The steam goes from the boiler to a set of small, high-pressure cylinders, then it is sent to a set of larger, low-pressure cylinders before exhausting to the atmosphere. This resulted in a fuel savings of about 20%, but called for additional maintenance. See also mallet and vauclain.

Crew: The fireman is responsible for keeping water and fire in the boiler, and for the general condition of the locomotive while on the road. The engineer is responsible for running the train safely down the line of track. The brakeman is responsible for the general condition of the train (apart from the locomotive) while on the road. The Conductor is responsible for keeping the schedule, the fares charged, and the condition and comfort of the passengers or freight. The conductor is the boss-man - all other members of the crew report to him.

Drivers: The driving wheels on a locomotive. Large Drivers: Steam engines are limited in the speed the mechanical parts can turn. It was said that the top speed of a locomotive was about equal to the driver diameter in inches. The Mogul, with 52" drivers, was a freight locomotive. The Columbia, with 76" drivers, was an express passenger locomotive. Smaller drivers also added leverage for heavy loads, and more small drivers meant better traction.

Eccentric: A crank converts back-and-forth motion to rotary motion. An eccentric does the reverse. The piston drives back-and-forth, turning the crank and the axle. The axle then turns the eccentric, which drives the valve back-and-forth.

Engine: Differentiated from locomotive, the engine is the mechanical set of cylinders, rods and valves that make a wheel go around. There are engines in boats, pumping stations and such. Locomotives are a combination of an engine, boiler, water tanks and such, designed to run on rails (or on roads) and to pull a load.

Fireless locomotive: A steam locomotive with no way of generating its' own steam. It had an insulated tank which was charged with steam from a factory boiler, and it ran on the residual heat. Used mostly in hazardous areas where a spark could spell disaster: cotton mills, jute mills, and explosives factories, and also in some industries that were equipped with large factory boilers.

Gauge: The distance between the inside edges of the rails. Standard Gauge is 4' 8", or 1,435 metres. "Narrow Gauge" is anything six inches (or more) less than standard. "Broad Gauge" is anything six inches (or more) wider. This is different from scale, which denotes the proportion of a model to its' full-size counterpart. Example: HO gauge denotes a specific gauge and scale combination: 16.5 mm track gauge, and a scale of 1:87. On30" is another gauge/scale reference: 16.5 mm track gauge, 1:48 scale, modelling a 30" gauge prototype. These two will run on the same track.

Gauge: A device for measuring pressures or levels at a distance. Typically on a steam locomotive there is a gauge glass, to measure the water level in the boiler, and a pressure gauge, to measure the steam pressure.

GoJo: Waterless hand cleaner for use in garages and Live Steam clubs. Contains pumice stone and other abrasives to remove grease, soot, tar, ash, grime, and even tough dirt.

Haycock: A method of stoking a fire in the firebox of a boiler. The usual locomotive fire is a saucer shape, deeper around the sides and thin in the center. The haycock adds a tall lip of coal just inside the firebox door, which preheats air coming through the door and also vibrates down to maintain the back edge of the saucer.

Mallet locomotive: The Mallet compound is an articulated locomotive in which the front engine runs on the exhaust steam from the rear engine. The rear engine drew its' steam off the boiler, and tended to slip until it had exhausted enough steam to power the front engine.

Notching up: Pulling the reversing lever of an engine valve gear back so that it requires less steam. The company notch is the designed optimal spot to place the reversing lever for peak efficiency.

Safety Valve: Steam boilers are fitted with a safety valve, which releases excess pressure. While designed to pop, oftentimes they can open in stages as the pressure approaches the max. They are said to wisp, simmer, sizzle, feather, and countless other expressions given to the image of the steam in each of these situations.

Slip Eccentrics: A simple valve gear with no levers to operate. In order to reverse the engine, you simply push it a half-turn of the crank in the direction you want it to run.

Tank locomotive, tender locomotive: A tank locomotive carries its' fuel and water supplies on the locomotive itself, in small tanks and a small bunker. In order to get a longer supply, the locomotive would pull a separate coal-and-water tender, directly behind, with these supplies. A saddle tank locomotive had the tanks arched over the top of the boiler, while a side tank tended to be more square, with the tanks sitting on the running boards. See the PICKLE BARREL (saddletanker) and HEW #33 (side tanker.)

Thou: Thousandth of an inch: The thickness of a cigarette-foil.

Town Lattice: Framing structure of a covered bridge, requiring smaller timbers than Howe Truss or Kingpost. It is amongst the simplest and most sturdy of all the bridge types.

Truss rods: Steel or iron rods within a wooden structure to take some of the weight and add strength to the structure. Found both on railway cars and wooden bridges.

Turnbuckle: Used to tighten a truss rod.

Valve timing: The valves admit steam to the cylinders at precisely the correct moment to develop the greatest power and efficiency. They also allow the used steam to exhaust from the cylinder when its' work is done.

Vauclain Compound: Baldwin developed a four-cylinder locomotive with high- and low-pressure cylinders set in pairs, working on a single crosshead and rod.

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