The Lark was an overnight passenger train of the Southern Pacific Company on the 470-mile run between San Francisco and Los Angeles. It became a streamliner in 1941 and was discontinued on April 8, 1968; the Lark ran along the same route as the Coast Daylight and was pulled by a locomotive wearing the famous Daylight paint scheme of orange and black. After 1941 Southern Pacific trains 75 and 76 were deluxe all-room Pullman trains between San Francisco' Third and Townsend Depot and Los Angeles's Union Station; the last two cars in each consist of the Lark ran along the east side of San Francisco Bay to Oakland and were known as the Oakland Lark. The Lark was to overnight travelers what the Morning Daylight and Noon Daylight were to day travelers in the San Francisco–Los Angeles market: safe, deluxe transportation; the Lark was the only streamlined all-room sleeping car train to operate within a single state and the only all-room train operating on the West Coast. The train's namesake, though neither nocturnal nor native to the New World, has symbolized the arrival of a new day through Chaucer and Shakespeare's sonnets which describe the lark's singing at first light.
The Southern Pacific Railroad started overnight trains 75 and 76, the Lark, on May 8, 1910. The SP ensured first-class service with the latest equipment, top-flight restaurant and lounge service and a choice of accommodations. In 1926 the schedule was 13-1/2 hours each way; the Padre ran overnight between Los Oakland on the Coast Line. In 1937 Southern Pacific introduced the Coast Daylight, a colorful set of streamlined cars in red and orange pulled by a 4-8-4 "Northern" steam locomotive streamlined in the same colors. In 1940 the SP added a second Daylight to the Coast Route and in July 1941 started the San Joaquin Daylight via Fresno. On March 2, 1941, the Lark became a streamlined 12-hour train with cars in two shades of gray pulled by the same locomotives that pulled the Daylights; this Lark had three of the five types of pre-war lightweight streamlined Pullman cars: the 100-series 10-roomette, 5-double bedroom. Food and beverage service was provided by the Lark Club, a three-car articulated food service unit that became known for late-night business transactions and a place to share a nightcap, in the morning, offered a full breakfast menu.
Late-night refreshments were offered in the 400-series sleeper-buffet-lounge-observation car which had two bedrooms, a compartment and a drawing room and carried the illuminated Lark drumhead on the rear. The two original observation cars, built in April 1941, had short working lives – the 400 was wrecked at Wellsona, California on September 19, 1941, while the 401 was written off after an accident at Casmalia, California, on December 5, 1942, they were replaced by the Pullman reassigning existing cars – the second 400 was the former 1939 New York World's Fair exhibition car American Milemaster, the replacement 401 was the experimental Muskingum River. Both cars were rebuilt with flat-ended observation lounges in 1956. During World War II coaches were added to the train along with 500-series 6-section, 6-roomette, 4-double bedroom cars reassigned from Overland Route service to the Oakland Lark. A few 9000-series 10-roomette, 6-double bedroom and 9300-series 22-roomette sleeping cars were built for the train in 1950, replacing some of the 1941 cars which were reassigned to other SP trains.
Diesels replaced the last steam locomotives in January 1955. More businessmen were leaving the train for the airlines. On July 15, 1957, the Lark was combined with an overnight chair car train; the Lark was no longer all-Pullman. The Oakland Lark was discontinued in 1960; the 1960s saw the removal of the triple-unit diner/lounge and the replacement of the two-tone gray color scheme by silver with a red stripe. The "Daylight" colors were gone from the locomotives, replaced by dark gray with a red nose. By the mid-sixties an average of fewer than 100 passengers were riding; the Southern Pacific tried to discontinue the Lark in late 1966 but public outcry and newspaper editorials urged the California Public Utilities Commission to order service for one more year. By the end of 1967 the Lark was down to a baggage car, one sleeping car, a couple of chair cars, an Automat car, pulled by a 3600-hp EMD SDP45; the train was still numbered 75 and 76. The Lark was discontinued on April 8, 1968. San Francisco, California.
The SP never painted any locomotives in the Lark colors of two-tone gray. They were replaced by American Locomotive Company PA-1 cab units a
The cylinder is the power-producing element of the steam engine powering a steam locomotive. The cylinder is made pressure-tight with a piston. Cylinders were cast in cast iron and in steel; the cylinder casting includes other features such as 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 provided by cast-iron bushings; the way the valve controlled the steam entering and leaving the cylinder was known as steam distribution and shown by the shape of the indicator diagram. What happened to the steam inside the cylinder was assessed separately from what happened in the boiler and how much friction the moving machinery had to cope with; this assessment was known as "engine performance" or "cylinder performance". The cylinder performance, together with the boiler and machinery performance, established the efficiency of the complete locomotive; the pressure of the steam in the cylinder was measured as the piston moved and the power moving the piston was calculated and known as cylinder power.
The forces produced in the cylinder moved the train but were damaging to the structure which held the cylinders in place. Bolted joints came loose, cylinder castings and frames cracked and reduced the availability of the locomotive. Cylinders may be arranged in several different ways. On early locomotives, such as Puffing Billy, the cylinders were set vertically and the motion was transmitted through beams, as in a beam engine; the next stage, for example Stephenson's Rocket, was to drive the wheels directly from steeply inclined cylinders placed at the back of the locomotive. Direct drive became the standard arrangement, but the cylinders were moved to the front and placed either horizontal or nearly horizontal; the front-mounted cylinders could be placed either outside. Examples: Inside cylinders, Planet locomotive Outside cylinders, GNR Stirling 4-2-2In the 19th and early 20th centuries, inside cylinders were used in the UK, but outside cylinders were more common in Continental Europe and the United States.
The reason for this difference is unclear. From about 1920, outside cylinders became more common in the UK but many inside-cylinder engines continued to be built. Inside cylinders give a more stable ride with less yaw or "nosing" but access for maintenance is more difficult; some designers used inside cylinders for aesthetic reasons. The demand for more power led to the development of engines with four cylinders. Examples: Three cylinders, SR Class V, LNER Class A4, Merchant Navy class Four Cylinders, LMS Princess Royal Class, LMS Coronation Class, GWR Castle Class On a two-cylinder engine the cranks, whether inside or outside, are set at 90 degrees; as the cylinders are double-acting this gives four impulses per revolution and ensures that there are no dead centres. On a three-cylinder engine, two arrangements are possible: cranks set to give six spaced impulses per revolution – the usual arrangement. If the three cylinder axes are parallel, the cranks will be 120 degrees apart, but if the centre cylinder does not drive the leading driving axle, it will be inclined, the inside crank will be correspondingly shifted from 120 degrees.
For a given tractive effort and adhesion factor, a three-cylinder locomotive of this design will be less prone to wheelslip when starting than a 2-cylinder locomotive. Outside cranks set at 90 degrees, inside crank set at 135 degrees, giving six unequally spaced impulses per revolution; this arrangement was sometimes used on three-cylinder compound locomotives which used the outside cylinders for starting. This will give evenly spaced exhausts. Two arrangements are possible on a four-cylinder engine: all four cranks set at 90 degrees. With this arrangement the cylinders act in pairs, so there are four impulses per revolution, as with a two-cylinder engine. Most four-cylinder engines are of this type, it is cheaper and simpler to use only one set of valve gear on each side of the locomotive and to operate the second cylinder on that side by means of a rocking shaft from the first cylinder's valve spindle since the required valve events at the second cylinder are a mirror image of the first cylinder.
Pairs of cranks set at 90 degrees with the inside pair set at 45 degrees to the outside pair. This gives eight impulses per revolution, it increases weight and complexity, by requiring four sets of valve gear, but gives smoother torque and reduces the risk of slipping. This was unusual in British practice but was used on the SR Lord Nelson class; such locomotives are distinguished by their exhaust beats, which occur at twice the frequency of a normal 2- or 4-cylinder engine. The valve chests or steam chests which contain the slide valves or piston valves may be located in various positions. If the cylinders are small, the valve chests may be located between the cylinders. For larger cylinders the valve chests are on top of the cylinders but, in early locomotives, they were sometimes underneath the cylinders; the valve chests are on top of the cylinders but, in older locomotives, the valve chests were sometimes located alongside the cylinders and inserted through slots in the frames. This meant that, while the cylinders were outside, the valves were inside a
Scrap consists of recyclable materials left over from product manufacturing and consumption, such as parts of vehicles, building supplies, surplus materials. Unlike waste, scrap has monetary value recovered metals, non-metallic materials are recovered for recycling. Scrap metal originates both in business and residential environments. A "scrapper" will advertise their services to conveniently remove scrap metal for people who don't need it. Scrap is taken to a wrecking yard, where it is processed for melting into new products. A wrecking yard, depending on its location, may allow customers to browse their lot and purchase items before they are sent to the smelters, although many scrap yards that deal in large quantities of scrap do not selling entire units such as engines or machinery by weight with no regard to their functional status. Customers are required to supply all of their own tools and labor to extract parts, some scrapyards may first require waiving liability for personal injury before entering.
Many scrapyards sell bulk metals by weight at prices below the retail purchasing costs of similar pieces. A scrap metal shredder is used to recycle items containing a variety of other materials in combination with steel. Examples are automobiles and white goods such as refrigerators, clothes washers, etc; these items are labor-intensive to manually sort things like plastic, copper and brass. By shredding into small pieces, the steel can be separated out magnetically; the non-ferrous waste stream requires other techniques to sort. In contrast to wrecking yards, scrapyards sell everything by weight, instead of by item. To the scrapyard, the primary value of the scrap is what the smelter will give them for it, rather than the value of whatever shape the metal may be in. An auto wrecker, on the other hand, would price the same scrap based on what the item does, regardless of what it weighs. If a wrecker cannot sell something above the value of the metal in it, they would take it to the scrapyard and sell it by weight.
Equipment containing parts of various metals can be purchased at a price below that of either of the metals, due to saving the scrapyard the labor of separating the metals before shipping them to be recycled. Scrap prices may vary markedly over time and in different locations. Prices are negotiated among buyers and sellers directly or indirectly over the Internet. Prices displayed. Other prices are not updated frequently; some scrap yards' websites have updated scrap prices. In the US, scrap prices are reported in a handful of publications, including American Metal Market, based on confirmed sales as well as reference sites such as Scrap Metal Prices and Auctions. Non-US domiciled publications, such as The Steel Index report on the US scrap price, which has become important to global export markets. Scrap yards directories are used by recyclers to find facilities in the US and Canada, allowing users to get in contact with yards. With resources online for recyclers to look at for scrapping tips, like web sites and search engines, scrapping is referred to as a hands and labor-intensive job.
Taking apart and separating metals is important to making more money on scrap, for tips like using a magnet to determine ferrous and non-ferrous materials, that can help recyclers make more money on their metal recycling. When a magnet sticks to the metal, it will be a ferrous material, like iron; this is a less expensive item, recycled but is recycled in larger quantities of thousands of pounds. Non-ferrous metals like copper and brass do not stick to a magnet; some cheaper grades of stainless steel are other grades are not. These items are higher priced commodities for metal recycling and are important to separate when recycling them; the prices of non-ferrous metals tend to fluctuate more than ferrous metals so it is important for recyclers to pay attention to these sources and the overall markets. Great potential exists in the scrap metal industry for accidents in which a hazardous material present in scrap causes death, injury, or environmental damage. A classic example is radioactivity in scrap.
Toxic materials such as asbestos, toxic metals such as beryllium and mercury may pose dangers to personnel, as well as contaminating materials intended for metal smelters. Many specialized tools used in scrapyards are hazardous, such as the alligator shear, which cuts metal using hydraulic force and scrap metal shredders. According to research conducted by the US Environmental Protection Agency, recycling scrap metals can be quite beneficial to the environment. Using recycled scrap metal in place of virgin iron ore can yield: 75% savings in energy. 90% savings in raw materials used. 86% reduction in air pollution. 40% reduction in water use. 76% reduction in water pollution. 97% reduction in mining wastes. Every ton of new steel made from scrap steel saves: 1,115 kg of iron ore. 625 kg of coal. 53 kg of limestone. Energy savings from other metals include: Aluminium savings of 95% energy. Copper savings of 85% energy. Lead savings of 65% energy. Zinc savings of 60% energy; the metal recycling industry encompasses a wide range of metals.
The more recycled metals are scrap steel, lead, copper, stainless steel and zinc. There are two main categories of metals: ferrous and
Lima Locomotive Works
Lima Locomotive Works was an American firm that manufactured railroad locomotives from the 1870s through the 1950s. The company took the most distinctive part of its name from its main shop's location in Ohio; the shops were located between the Baltimore & Ohio's Cincinnati-Toledo main line and the Nickel Plate Road main line and shops. The company is best known for producing the Shay geared logging-steam locomotive, developed by Ephraim Shay, for William E. Woodard's "Super Power" advanced steam locomotive concept – exemplified by the prototype 2-8-4 Berkshire, Lima demonstrator A-1. In World War II the Lima plant produced the M4A1 version of the M4 Sherman tank. In 1878 James Alley contracted the Lima Machine Works to build a steam locomotive that Ephraim Shay had designed. In April 1880, Lima rebuilt Ephraim Shay's original design, using vertically side-mounted pistons mounted on the right, connected to a drive line on the outside of the trucks; the Shay was geared down to provide more slow-moving, pulling ability for use in the lumber industry.
The first Shay locomotive was built in 1880. To accommodate the new demand for the locomotive, Shay licensed the right to build his locomotive to the Lima Machine Works, which expanded and began to ship Shay locomotives to lumbermen across the frontier. Two years locomotives were the main product being produced by the Lima Machine Works, which would produce over 300 locomotives during the next ten years. After a serious fire, a new shop was opened in 1902 and Shay production continued. With initial demand for low-speed geared locomotives well on the way to being sated, the new facilities in place, Lima moved into the heavy railroad locomotive field. Success returned to Lima in the 1920s with the new concept of "Super Power" developed by Lima's mechanical engineer William E. Woodard. By making a number of significant changes to maximize a steam locomotive's capacity to generate and utilize steam, Woodard was able to make such locomotives more powerful and faster, he did this by starting in 1922 with the H-10 experimental heavy 2-8-2 design for the New York Central and applying both new science, every efficiency-enhancing tool available – a larger firebox, increased superheat, a feedwater heater, improved draughting, higher boiler pressure, streamlined steam passages and a trailing-truck booster engine, by applying limited cutoff to prevent locomotive engineers from using excessive steam at starting.
The 2-8-2 thus produced was demonstrated to be 26% more efficient overall than its immediate predecessor, the NYC bought 301 locomotives. A large increase in firebox area, characteristic of his work, necessitated adding another axle to the trailing truck, thus creating the 2-8-4 wheel arrangement. Built in the spring of 1925, the first Berkshire was dubbed the A-1. In addition to supporting the large firebox and grate, the four-wheeled trailing truck carried the ash pan. For this purpose, the truck was redesigned as an articulated extension of the locomotive frame; the result was an ash pan which could hold more ash, allowing the locomotive to travel farther between cleanings. For roads which burned coal, this was a significant innovation, but it was not without tradeoffs. The articulated frame reduced weight on the driving wheels; the locomotives so configured had more difficulty staying on the rails in reverse through yard trackwork like switch frogs. The locomotive proved to be 26-30% more efficient than the New York Central H-10.
After a successful series of tests in the mid-1920s it was sent around the country to make the idea of "Super Power" known. The first forty-five were purchased by New York Central's subsidiary Boston & Albany following initial road testing across the summit of the Berkshire Hills, so the 2-8-4 wheel arrangement came to be known as the "Berkshire" on most railroads; the prototype itself was sold to the Illinois Central as part of an order for 50 similar locomotives. Woodard summed up "Super Power" by defining it as "horsepower at speed". Previous design principles emphasized tractive effort rather than speed. By 1949 some 613 Berkshires had been constructed for North American service, of which twenty are preserved – at least two in operating condition, both Lima products. There were at least three successive waves of "Super Power"; the first began with NYC 8000 and the A-1, included Missouri Pacific 2-8-4s and Texas & Pacific 2-10-4s. These locomotives had conventional 63" driving wheels. In 1927, the Erie Railroad took delivery of a "second-phase" Berkshire with 70" driving wheels, capable not only of great power but higher speed.
The "third-phase" of the 1930s and war years can be identified with locomotives such as the homebuilt N&W 2-6-6-4s, C&O/Virginian 2-6-6-6 and all American 4-8-4s. Boiler pressures rose as high as 310 lbs/sq.in.. And the "Super Power" concept had extended to other builders such as Baldwin; the four-wheel trailing truck became the standard for large locomotives, though the articulated main frame did not
A booster engine for steam locomotives is a small two-cylinder steam engine back-gear-connected to the trailing truck axle on the locomotive or, if none, the lead truck on the tender. A rocking idler gear permits it to be put into operation by the engineer, it would drive one axle only and could be non-reversible with one idler gear or reversible with two idler gears. They were used to maintain low speed under demanding conditions, it could be cut in while moving at speeds under 15 to 20 mph. Rated at about 300 hp at speeds of from 10 to 30 miles per hour, it would automatically cut out depending on the model and design. Tractive effort of 10-12,000 lbf was common, although ratings of up to around 15,000 lbf were possible. Tender boosters were equipped with side-rods connecting axles on the lead truck; such small side-rods restricted speed and thus confined to switching locomotives used in transfer service between yards. Such boosters were far rarer than engine boosters; the booster is intended to address fundamental flaws of the standard steam locomotive.
First, most steam locomotives do not provide power to all wheels. The amount of force that can be applied to the rail depends on the weight on driven wheels and the factor of adhesion of the wheels against the track. Unpowered wheels ` waste' weight. Unpowered wheels are needed to provide stability at speed, but at low speed this is not necessary. Second, the "gearing" of a steam locomotive is constant, since the pistons are linked directly to the wheels via rods and cranks. Since this is fixed, a compromise must be struck between ability to haul at low speed and the ability to run fast without inducing excessive piston speeds or the exhaustion of steam; this compromise means that the steam locomotive at low speeds is not able to use all the power the boiler is capable of producing. The booster enables. Boosters were costly to maintain with their flexible steam and exhaust pipes, idler gear etc; the booster saw. Railway systems elsewhere considered the expense and complexity unjustified. In the North American region, booster engines were applied to only a fraction of all locomotives built.
Some railroads used boosters extensively. The New York Central applied it to all of its 4-6-4 Hudson locomotives; the rival Pennsylvania Railroad, used few booster-equipped locomotives. Canadian Pacific Railway rostered 3,257 steam locomotives acquired between 1881 and 1949, yet only 55 were equipped with boosters. 17 H1 class 4-6-4s, 2 K1 class 4-8-4s and all 36 T1 class 2-10-4s. In Australia, Victorian Railways equipped all but one of its X class 2-8-2 locomotives with a'Franklin' two cylinder booster engine after the successful trial of the device on a smaller N class 2-8-2 in 1927; the South Australian Railways 500 class 4-8-2 heavy passenger locomotives were rebuilt into 4-8-4s with the addition of a booster truck from 1929 onwards. NZR's Kb class of 1939 were built with a booster truck to enable the locomotives to handle the steeper grades of some South Island lines; some boosters were removed because of gear jammings. In Great Britain, the Gresley P1 2-8-2 locomotives for the London and North Eastern Railway, of which only two were built, were equipped with booster units.
An early type of booster used in Great Britain was the steam tender, tried in 1859 by Benjamin Connor of the Caledonian Railway. Archibald Sturrock patented a similar system on 6 May 1863. Bruce, Alfred W.. The Steam Locomotive in America. Bonanza Books, New York. Railway Master Mechanics' Association. Locomotive Cyclopedia of American Practice, Sixth Edition—1922. Simmons-Boardman. Franklin Type C2 Booster Engine Talbot, Fred. A, "The locomotive "booster"", Railways of the World, pp. 84–91 illustrated description of the booster engine
Southern Pacific Transportation Company
The Southern Pacific was an American Class I railroad network that existed from 1865 to 1998 that operated in the Western United States. The system was operated by various companies under the names Southern Pacific Railroad, Southern Pacific Company and Southern Pacific Transportation Company; the original Southern Pacific began in 1865 as a land holding company. The last incarnation of the Southern Pacific, the Southern Pacific Transportation Company, was founded in 1969 and assumed control of the Southern Pacific system; the Southern Pacific Transportation Company was acquired by the Union Pacific Corporation and merged with their Union Pacific Railroad. The Southern Pacific Transportation Company was the surviving railroad as it absorbed the Union Pacific Railroad and changed its name to "Union Pacific Railroad"; the Southern Pacific Transportation Company is now the current incarnation of the Union Pacific Railroad. The Southern Pacific legacy founded hospitals in San Francisco, Tucson and elsewhere.
In the 1970s, it founded a telecommunications network with a state-of-the-art microwave and fiber optic backbone. This telecommunications network became part of Sprint, a company whose name came from the acronym for Southern Pacific Railroad Internal Networking Telephony; the original Southern Pacific, Southern Pacific Railroad, was founded as a land holding company in 1865 acquiring the Central Pacific Railroad through leasing. By 1900, the Southern Pacific system was a major railroad system incorporating many smaller companies, such as the Texas and New Orleans Railroad and Morgan's Louisiana and Texas Railroad, it extended from New Orleans through Texas to El Paso, across New Mexico and through Tucson, to Los Angeles, through most of California, including San Francisco and Sacramento. Central Pacific lines extended east across Nevada to Ogden and reached north through Oregon to Portland. Other subsidiaries included the St. Louis Southwestern Railway, El Paso and Southwestern Railroad, the Northwestern Pacific Railroad at 328 miles, the 1,331-mile Southern Pacific Railroad of Mexico, a variety of 3 ft narrow gauge routes.
The SP was the defendant in the landmark 1886 United States Supreme Court case Santa Clara County v. Southern Pacific Railroad, interpreted as having established certain corporate rights under the Constitution of the United States; the Southern Pacific Railroad was replaced by the Southern Pacific Company and assumed the railroad operations of the Southern Pacific Railroad. In 1929, Southern Pacific/Texas and New Orleans operated 13,848 route-miles not including Cotton Belt, whose purchase of the Golden State Route circa 1980 nearly doubled its size to 3,085 miles, bringing total SP/SSW mileage to around 13,508 miles. In 1969, the Southern Pacific Transportation Company was established and took over the Southern Pacific Company. By the 1980s, route mileage had dropped to 10,423 miles due to the pruning of branch lines. In 1988, the Southern Pacific Transportation Company was taken over by Rio Grande Industries, the parent company that controlled the Denver and Rio Grande Western Railroad. Rio Grande Industries did not merge the Southern Pacific Transportation Company and the Denver and Rio Grande Western Railroad together, but transferred direct ownership of the Denver and Rio Grande Western Railroad to the Southern Pacific Transportation Company, allowing the combined Rio Grande Industries railroad system to use the Southern Pacific name due to its brand recognition in the railroad industry and with customers of both the Southern Pacific Transportation Company and the Denver and Rio Grande Western Railroad.
A long time Southern Pacific subsidiary, the St. Louis Southwestern Railway was marketed under the Southern Pacific name. Along with the addition of the SPCSL Corporation route from Chicago to St. Louis, the total length of the D&RGW/SP/SSW system was 15,959 miles. Rio Grande Industries was renamed Southern Pacific Rail Corporation. By 1996, years of financial problems had dropped Southern Pacific's mileage to 13,715 miles; the financial problems caused the Southern Pacific Transportation Company to be taken over by the Union Pacific Corporation. The Union Pacific Corporation merged the Denver and Rio Grande Western Railroad, the St. Louis Southwestern Railway and the SPCSL Corporation into their Union Pacific Railroad, but did not merge the Southern Pacific Transportation Company into the Union Pacific Railroad. Instead, the Union Pacific Corporation merged the Union Pacific Railroad into the Southern Pacific Transportation Company in 1998; the Southern Pacific Transportation Company became the current incarnation of the Union Pacific Railroad.
Like most railroads, the SP painted most of its steam locomotives black during the 20th century, but after 1945 SP painted the front of the locomotive's smokebox silver (almost
A smokebox is one of the major basic parts of a steam locomotive exhaust system. Smoke and hot gases pass from the firebox through tubes where they pass heat to the surrounding water in the boiler; the smoke enters the smokebox, is exhausted to the atmosphere through the chimney. Early locomotives had no smokebox and relied on a long chimney to provide natural draught for the fire but smokeboxes were soon included in the design for two main reasons. Firstly and most the blast of exhaust steam from the cylinders, when directed upwards through an airtight smokebox with an appropriate design of exhaust nozzle draws hot gases through the boiler tubes and flues and fresh combustion air into the firebox. Secondly, the smokebox provides a convenient collection point for ash and cinders drawn through the boiler tubes, which can be cleaned out at the end of a working day. Without a smokebox, all char must pass up the chimney or will collect in the tubes and flues themselves blocking them; the smokebox appears to be a forward extension of the boiler although it contains no water and is a separate component.
Smokeboxes are made from riveted or welded steel plate and the floor is lined with concrete to protect the steel from hot char and acid or rainwater attack. To assist the passage of the smoke and hot gases, a blower is used; this is a pipe ending in a ring containing pin-sized holes. The steam draws further gases through the tubes; this in turn causes air to be drawn through the firehole, making the fire burn hotter. When the locomotive is in motion, exhaust steam passes through the blastpipe, located within the smokebox; the steam is ejected through the chimney. The blastpipe is. Ashes and soot which may be present in the smoke are deposited in the smokebox; the front of the smokebox has a door, opened to remove these deposits at the end of each locomotive's working day. The handle must be tightened to prevent air leaks, which would reduce the draw on the fire and can allow any unburnt char at the bottom of the smokebox to catch fire there; some smokebox doors have a single handle in the form of a wheel.
On many steamrollers an extension to the body of the smokebox houses the bearing which supports the front roller. Due to limitations of space, these rollers have a drop-down flap instead of a circular smokebox door; the smokebox incorporates the main steam pipes from the regulator, one leading to each valve chest, a part of the cylinder casting. These may pass through the smokebox wall to join with the cylinder or may stay within the profile of the smokebox. Inside steam pipes do not require lagging as the smokebox keeps them warm, but outside steam pipes are more common for locomotives with cylinders outside the frames; some locomotive classes used both types depending on the date. Because heat losses from the smokebox are of little consequence, it is not lagged. In most cases it appears to be the same diameter as the boiler in the finished locomotive but this only because of the boiler cladding. Tank engines had their water tanks stop short of the unlagged smokebox as it could raise the temperature of the water sufficiently to cause problems with the injectors.
British Railways standard classes use this design, where a robust mesh grille is incorporated into the smokebox, forming a filter between the front tubeplate and the exhaust. Any large pieces of char passing through the boiler tubes tend to be broken up on impact with the mesh, creating finer particles which are swept up the chimney instead of accumulating in the bottom of the smokebox; this does not negate the need to clean out the smokebox but reduces the amount of work that has to be done. In the best case, smokebox cleaning could be avoided between boiler washouts at intervals of two weeks; the classic layout of a steam locomotive has the smokebox and chimney at the front of the locomotive, referred to as travelling "smokebox-first". Some designs reversed the layout to avoid problems caused by having the exhaust blowing back onto the crew. A spark arrester is installed within the smokebox; this may take the form of a cylindrical mesh running from the top of the blast pipe to the bottom of the chimney.
The purpose of a spark arrester is to prevent excessively large fragments of hot ash from being exhausted into the environment where they may pose a fire risk. For this reason, spark arresters are installed on locomotives running through dry environments, they should not be confused with the external spark arrestors fitted to some locomotives. The presence of a spark arrester may have a thermodynamic effect, distorting the draw of air over the fire and thereby reducing total power output, thus their use can be contentious. Locomotives fitted with a superheater will have a superheater header in the smokebox. Steam enters the header as "wet" steam, passes through a superheater element; this takes the form of a pipe. The steam enters a separate chamber in this time as superheated or dry steam; the advantage of superheating is that the steam has greater expansive properties when entering the cylinders, so more power can be gained from a smaller amoun