The Kuhn slide is part of a modified Walschaerts valve gear on steam locomotives and is named after its inventor, Michael Kuhn. The term is used to refer to this particular type of Walschaerts valve gear system as a whole. Problems arise in incorporating a Walschaerts valve gear into the design of tank and narrow gauge locomotives because of space limitations; the reversing rod, needed to change between forward and reverse running, is therefore mounted at the same level as the pivot of the expansion link. This enables the lifting link to be dispensed with, the lifting arm to be connected directly to the radius rod. To ensure the required horizontal movement, the back end of the radius rod is designed as a slide which fits into a rotatable crosshead in the lifting arm; the Kuhn valve gear was not as widespread as the classic Walschaerts valve gear as its production costs were higher. One advantage of the Kuhn slide is that it runs smoothly in either direction. For that reason it was preferred on tank locomotives which, for operational reasons had to run backwards for long periods.
A variation of the Kuhn slide was developed by the Winterthur Locomotive Works. On the so-called Winterthur valve gear the expansion link itself is attached to the reversing shaft, both having a common pivot
A truck or lorry is a motor vehicle designed to transport cargo. Trucks vary in size and configuration. Commercial trucks can be large and powerful, may be configured to mount specialized equipment, such as in the case of fire trucks, concrete mixers, suction excavators. Modern trucks are powered by diesel engines, although small to medium size trucks with gasoline engines exist in the US, Mexico. In the European Union, vehicles with a gross combination mass of up to 3.5 t are known as light commercial vehicles, those over as large goods vehicles. Trucks and cars have a common ancestor: the steam-powered fardier Nicolas-Joseph Cugnot built in 1769. However, steam wagons were not common until the mid-1800s; the roads of the time, built for horse and carriages, limited these vehicles to short hauls from a factory to the nearest railway station. The first semi-trailer appeared in 1881, towed by a steam tractor manufactured by De Dion-Bouton. Steam-powered wagons were sold in France and the United States until the eve of World War I, 1935 in the United Kingdom, when a change in road tax rules made them uneconomic against the new diesel lorries.
In 1895 Karl Benz designed and built the first truck in history using the internal combustion engine. That year some of Benz's trucks were modified to become the first bus by the Netphener, the first motorbus company in history. A year in 1896, another internal combustion engine truck was built by Gottlieb Daimler. Other companies, such as Peugeot, Renault and Büssing built their own versions; the first truck in the United States was built by Autocar in 1899 and was available with optional 5 or 8 horsepower motors. Trucks of the era used two-cylinder engines and had a carrying capacity of 3,300 to 4,400 lb. In 1904, 700 heavy trucks were built in the United States, 1000 in 1907, 6000 in 1910, 25000 in 1914. After World War I, several advances were made: pneumatic tires replaced the common full rubber versions. Electric starters, power brakes, 4, 6, 8 cylinder engines, closed cabs, electric lighting followed; the first modern semi-trailer trucks appeared. Touring car builders such as Ford and Renault entered the heavy truck market.
Although it had been invented in 1897, the diesel engine did not appear in production trucks until Benz introduced it in 1923. The diesel engine was not common in trucks in Europe until the 1930s. In the United States, Autocar introduced engines for heavy applications in the mid-1930s. Demand was high enough Autocar launched the "DC" model in 1939. However, it took much longer for diesel engines to be broadly accepted in the US: gasoline engines were still in use on heavy trucks in the 1970s. Truck is used in American English, is common in Canada, New Zealand, Puerto Rico and South Africa, while lorry is the equivalent in British English, is the usual term in countries like the United Kingdom, Malaysia and India; the word "truck" might come from a back-formation of "truckle", meaning "small wheel" or "pulley", from Middle English trokell, in turn from Latin trochlea. Another possible source is the Latin trochus, meaning "iron hoop". In turn, both sources emanate from trekhein; the first known usage of "truck" was in 1611, when it referred to the small strong wheels on ships' cannon carriages.
In its extended usage it came to refer to carts for carrying heavy loads, a meaning known since 1771. Its expanded application to "motor-powered load carrier" has been in usage since 1930, shortened from "motor truck", which dates back to 1901."Lorry" has a more uncertain origin, but has its roots in the rail transport industry, where the word is known to have been used in 1838 to refer to a type of truck a large flat wagon. It derives from the verb lurry of uncertain origin, its expanded meaning, "self-propelled vehicle for carrying goods", has been in usage since 1911. Before that, the word "lorry" was used for a sort of big horse-drawn goods wagon. In the United States and the Philippines "truck" is reserved for commercial vehicles larger than normal cars, includes pickups and other vehicles having an open load bed. In Australia, New Zealand and South Africa, the word "truck" is reserved for larger vehicles. In the United Kingdom, Malaysia, Singapore and Hong Kong lorry is used instead of truck, but only for the medium and heavy types.
Produced as variations of golf cars, with internal combustion or battery electric drive, these are used for off-highway use on estates, golf courses, parks. While not suitable for highway use some variations may be licensed as slow speed vehicles for operation on streets as a body variation of a neighborhood electric vehicle. A few manufactures produce specialized chassis for this type of vehicle, while Zap Motors markets a version of their xebra electric tricycle. Popular in Europe and Asia, many mini trucks are factory redesigns of light automobiles with monocoque bodies. Specialized designs with substantial frames such as the Italian Piaggio shown here are based upon Japanese designs and are popular for use in "old town" sections of European cities that have narrow alleyways. Regardless of name, these smal
Gab valve gear
Gab valve gear was an early form of valve gear used on steam engines. Its simplest form allowed an engine to be started. A double form used on steam locomotives, allowed easy reversing; the word gab or gabb may derive from a word for mouth, recorded by the Oxford English Dictionary from 1724, medieval in origin from other forms related to gossip or idle chatter. The OED gives the steam engine sense of gab as a notch in the valvegear as being of Flemish origin, from the word gabbe; this is cited in the OED from 1792. The OED cites the derivative gab-lever from 1839. One of the first self-acting valve gears used for steam engines was the eccentric valve gear; this placed an eccentric on the engine's crankshaft, that in turn drove a strap and a long rod to the valve's actuating spindle. This was a simple valve gear but worked well for rotative engines that ran continuously for long periods, in only one direction. For early mill engines this was acceptable; the simplest form of gab valve gear or'gab clutch' was a simple notch in the valve rod, where it hooked over the valve spindle.
A hand lever allowed this notch to be lifted, thus disengaging the valve drive and promptly stopping the engine. Where an engine had to be stopped and started such as for a winding engine, it was useful to do this by means of the valve gear; this allows the engine to be stopped within a fraction of a revolution, where using a throttle or stop valve in the steam supply slowed the engine and so would be far less precise. Winding engines for mineshafts were required to be reversed, for hoisting and lowering of the shaft cage; these engines began with a gab clutch. The eccentric is loose on the crankshaft and can rotate between two stops; these stops represent the positions for the eccentric to run the engine in each direction. When the gab was disengaged and the crankshaft stopped, the manual lever was used to drive the engine valves in reverse, which re-set the eccentric to the opposing position; the gab could now be re-engaged and the engine restarted in the opposing direction. With the development of the first steam locomotives, reversing was an obvious necessity.
Stephenson's Locomotion used slip-eccentrics although these were soon considered impractical, owing to the lack of access to the crank axles acting as both carrying axle and crankshaft. A somewhat contrived method used for the replica Locomotion is to try and display it on a track with raised ends, so that the locomotive can be allowed to roll backwards under its own weight, re-setting its own eccentrics. A better solution was to provide two of them, one for each direction; the required eccentric, direction, was selected by engaging only one gab at a time. The first locomotive gab gears used two'open' gabs, side by side, each hooking over the same pin. If both gabs were engaged these would jam damaging the valve rod. On the footplate of a rattling locomotive with no suspension and a poor trackbed, this is known to have been the cause of breakdowns, whether by driver error or by a loose gab slipping into accidental engagement; as the gabs, unlike in the stationary engine, were remote from the driver they were provided with wide V-shaped jaws to help them engage with the pins.
A better solution was to use a single double-sided gab. These were X-shaped and sat between the two connecting pins. X-gabs were usually reversed, so that the gab was placed on the valve spindle and the pins were instead connected to the eccentric rods; the gab now stayed still vertically and the pins were moved up and down to engage them. This was done by joining both pins with a short vertical bar; the driver's reversing lever moved the centre of this bar, thus the pins, up and down to engage one at a time with opposite faces of the X-gab. This valve gear was used on Stephenson's locomotives of the early 1830s, such as Rocket. Another mechanism, used on Stephenson's locomotives in the 1830s, was the'coupled gab'. Two open gabs were used, as for the manual open gab, although in this case they were both operated automatically by a single reversing lever. One was actuated by a bellcrank, the other through a reversing linkage from this, so that as one engaged the other was lifted clear; the final form of the gab valve gear was the'closed' gab.
Like the X-gab, this was a coupled pair of gabs, although in this case they faced inwards and there was a single pin between them. Once again, the gabs were driven by the eccentrics and the pin drove the valve spindle; the use of expansive working was recognised for stationary engines, although this was only required for engines working under a constant load. By shutting off the supply of steam early, the steam within the cylinder was allowed to expand whilst doing work against the piston; this provided considerable savings in efficiency of both water consumption. In 1844, William Williams, a pattern-maker for Stephenson, made the remarkable invention of realising that if a closed gab was made into a curved link, so that it fitted the pin throughout its travel the valve gear could be set into an intermediate position, that this would have the effect of giving expansive working; this gear was the genesis of the well-known Stephenson link gear
William Mason (locomotive builder)
William Mason was a master mechanical engineer and builder of textile machinery and railroad steam locomotives. He founded Mason Machine Works of Massachusetts, his company was a significant supplier of locomotives and rifles for the Union Army during the American Civil War. The company later produced printing presses. Mason was born in 1808 in Mystic, the son of a blacksmith; as a boy, Mason spent time in his father's shops. He left home at the age of thirteen and worked as an operator in the spinning room of a small cotton factory in Canterbury, Connecticut, he could repair the most complicated machine in the mill. At the age of sixteen he went to East Haddam, where a mill for the manufacture of thread was being established, to start the machines. At seventeen he worked at the machine shop connected with the mill, it was here he set up the first power loom in the country for the manufacture of diaper linen. He constructed an ingenious loom for the weaving of damask table cloths. In 1833, Mason joined Asell Lamphaer at Connecticut, to make the ring-frame for spinning.
He perfected the "ring" along with an improved frame. In 1835, Mason moved to Taunton, Massachusetts, to join Crocker and Richmond, manufacturers of cotton machinery, he worked entirely on ring frames. The firm failed in 1837 during the financial crisis; the business was taken over by Messrs Keith. Mason was employed as foreman. On October 8, 1840, his greatest invention, a "self-acting mule" was patented. Competition required improvements and on October 3, 1846, he received a patent for "Mason's Self-acting Mule." Though the company would later venture into the production of locomotives and printing presses, the production of textile machinery would be its most important sector until the 19th century. Leach and Keith suffered a failure in the winter of 1842 owing Mason a large amount of money. James K. Mills & Co. of Boston, a leading commission firm, came to his rescue and helped him to buy out the former partners. In 1845, new buildings were erected and the plant became the largest one devoted to the manufacture of machinery in the country.
It made cotton machinery, woolen machinery, machinists' tools, cupola furnaces, shafting, railroad car wheels made with spokes, after 1852, locomotives. Mason wanted to improve the symmetry of the American locomotive. A first engine was turned out in 1853. In 1857 his firm failed but he managed to reopen the plant soon afterwards; the textile business recovered but the locomotive business was less prosperous. By 1860, he had produced a total of only 100 engines; the figure was doubled by 1865 due to the wartime demand and the pace continued for the next several years. During the American Civil War, 600 Springfield rifles were turned out weekly. Mason's locomotives were genuinely handsome without ornaments, his influence was exerted over all locomotive builders at the time and later. In 1856 he built two locomotives for the Cairo and Alexandria Railroad of Egypt in which a commentator said that the engines' excellence was due to the accuracy of execution attained by an admirable set of tools and a skillful set of workmen.
Opinion by master mechanics was. In 1871, the Mason Bogie was introduced; the business was organized as the Mason Machine Works in 1873 with a capital of $800,000. Mason died May 1883 of pneumonia, he is buried at Mount Pleasant Cemetery in Massachusetts. The 700th engine was being completed. Only 54 more engines were completed by 1889 and delivered in 1890; the company continued to build cotton machinery. William Mason was a good violinist, he made gifts to charity. He is remembered as a pioneer in the building of locomotives. Taunton and Mason: Cotton Machinery and Locomotive Manufacture in Taunton, Massachusetts, 1811-1861, by John William Lozier, Ph.d Dissertation Thesis at Ohio State University 1978. Copies at Old Colony Historical Society in Taunton and at The Baker Business School Library at Harvard University. Mason Machine Works; the Mason Machine Works, Taunton Massachusetts, U. S. A.: Inventors and Builders of Cotton Machinery. Taunton, Mass.: The Company, 1898. Photograph of William Mason William Mason Papers, 1839 - 1857 Archives Center, National Museum of American History, Smithsonian Institution.
The National Cyclopaedia of American Biography By James Terry White, published 1909 William Mason article Volume 10, Page 386. History of Bristol County, Massachusetts: With Biographical Sketches of Many of its Pioneers and Prominent Men, compiled by Duane Hamilton Hurd, published 1883. William Mason article on page 886. Investigating Disruptive Technology, The Emergence Of Ring Spinning In The American Textile Industry
A narrow-gauge railway is a railway with a track gauge narrower than standard 1,435 mm. Most narrow-gauge railways are between 600 1,067 mm. Since narrow-gauge railways are built with tighter curves, smaller structure gauges, lighter rails, they can be less costly to build and operate than standard- or broad-gauge railways. Lower-cost narrow-gauge railways are built to serve industries and communities where the traffic potential would not justify the cost of a standard- or broad-gauge line. Narrow-gauge railways have specialized use in mines and other environments where a small structure gauge necessitates a small loading gauge, they have more general applications. Non-industrial, narrow-gauge mountain railways are common in the Rocky Mountains of the United States and the Pacific Cordillera of Canada, Switzerland, the former Yugoslavia and Costa Rica. In some countries, narrow gauge is the standard. Narrow-gauge trams metre-gauge, are common in Europe. In general, a narrow-gauge railway is narrower than 1,435 mm.
Because of historical and local circumstances, the definition of a narrow-gauge railway varies. The earliest recorded railway appears in Georgius Agricola's 1556 De re metallica, which shows a mine in Bohemia with a railway of about 2 ft gauge. During the 16th century, railways were restricted to hand-pushed, narrow-gauge lines in mines throughout Europe. In the 17th century, mine railways were extended to provide transportation above ground; these lines were industrial. These railways were built to the same narrow gauge as the mine railways from which they developed; the world's first steam locomotive, built in 1802 by Richard Trevithick for the Coalbrookdale Company, ran on a 3 ft plateway. The first commercially successful steam locomotive was Matthew Murray's Salamanca built in 1812 for the 4 ft 1 in Middleton Railway in Leeds. Salamanca was the first rack-and-pinion locomotive. During the 1820s and 1830s, a number of industrial narrow-gauge railways in the United Kingdom used steam locomotives.
In 1842, the first narrow-gauge steam locomotive outside the UK was built for the 1,100 mm -gauge Antwerp-Ghent Railway in Belgium. The first use of steam locomotives on a public, passenger-carrying narrow-gauge railway was in 1865, when the Ffestiniog Railway introduced passenger service after receiving its first locomotives two years earlier. Many narrow-gauge railways were part of industrial enterprises and served as industrial railways, rather than general carriers. Common uses for these industrial narrow-gauge railways included mining, construction, tunnelling and conveying agricultural products. Extensive narrow-gauge networks were constructed in many parts of the world. Significant sugarcane railways still operate in Cuba, Java, the Philippines, Queensland, narrow-gauge railway equipment remains in common use for building tunnels; the first use of an internal combustion engine to power a narrow-gauge locomotive was in 1902. F. C. Blake built a 7hp petrol locomotive for the Richmond Main Sewerage Board sewage plant at Mortlake.
This 2 ft 9 in gauge locomotive was the third petrol-engined locomotive built. Extensive narrow-gauge rail systems served the front-line trenches of both sides in World War I, they were a short-lived military application, after the war the surplus equipment created a small boom in European narrow-gauge railway building. Narrow-gauge railways cost less to build because they are lighter in construction, using smaller cars and locomotives, smaller bridges and tunnels, tighter curves. Narrow gauge is used in mountainous terrain, where engineering savings can be substantial, it is used in sparsely populated areas where the potential demand is too low for broad-gauge railways to be economically viable. This is the case in parts of Australia and most of Southern Africa, where poor soils have led to population densities too low for standard gauge to be viable. For temporary railways which will be removed after short-term use, such as logging, mining or large-scale construction projects, a narrow-gauge railway is cheaper and easier to install and remove.
Such railways have vanished, due to the capabilities of modern trucks. In many countries, narrow-gauge railways were built as branch lines to feed traffic to standard-gauge lines due to lower construction costs; the choice was not between a narrow- and standard-gauge railway, but between a narrow-gauge railway and none at all. Narrow-gauge railways cannot interchange rolling stock with the standard- or broad-gauge railways with which they link, the transfer of passengers and freight require time-consuming manual labour or substantial capital expenditure; some bulk commodities, such as coal and gravel, can be mechanically transshipped, but this is time-consuming, the equipment required for the transfer is complex to maintain. If rail lines with other gauges coexist in a network, in times of peak demand i
Boston, Revere Beach and Lynn Railroad
The Boston, Revere Beach and Lynn Railroad was a 3 ft narrow gauge passenger-carrying short line railroad between East Boston and Lynn, Massachusetts from 1875 to 1940. The railroad was chartered May 5, 1874 and opened July 29, 1875. A ferry connection from its southern terminus at East Boston connected to Rowes Wharf in the city of Boston proper, with a connection to the Atlantic Avenue Elevated; the railroad followed the coastline north-eastward through the resort of Revere Beach to the far terminus at Lynn. A branch split at Orient Heights to a loop through Winthrop; the rail laid was light, 30-pound per yard rail being installed at first, increased to 50 lb/yd in 1885 and 60 lb/yd in 1904. It was, laid from the beginning on standard gauge-sized ties. Given the lightweight rail, the locomotives were small and of 3 ft narrow gauge dimensions; the vast majority of them were Mason Bogies, 11 from the Mason Machine Works and a further 21 from other builders after Mason closed. Cars were of 3 ft narrow gauge dimensions, seating four across.
Between 1896 and 1900, the section from Revere Beach to Point of Pines running along the beach, was relocated inland to lie next to the Eastern Railroad's abandoned Chelsea Beach Branch. The stations were moved and a new one was built. Revere Beach Boulevard was built along the former route; the railroad was successful, carrying commuters into Boston and the Boston urban population to the seaside resorts. By 1914 over seven million passengers were carried annually, making it one of the most traveled stretches of railroad in North America. With such a traffic density, the expense of electrification could be recouped. By 1928, all existing cars were fitted with electric motors, trolley poles, control stands and the steam locomotives were disposed of. However, the Great Depression and increased use of the automobile caused ridership to decline. After attempts to find a buyer fell through, the BRB&L filed for bankruptcy in 1937. Further losses of ridership followed, in 1939 the management petitioned for abandonment.
This was granted, the railroad ceased operations on January 27, 1940. The right-of-way from East Boston to Revere, a length of 4.3 miles, was used in 1952–1954 to build part of the Massachusetts Bay Transportation Authority's Blue Line rapid transit line. The remainder of the right-of-way is owned by the Commonwealth of Massachusetts and may be used for further expansion of the Blue Line. South of the Blue Line's section, the line passed through where Logan Airport is now and a now-abandoned tunnel under a hill. A number of the passenger cars were purchased by the East Broad Top Railroad in Pennsylvania, where two or three survive; the line's Orient Heights Car shop survives, having been converted to a casket factory after the closure of the line. On July 1, 1891, the BRB&L merged with the 3 ft narrow gauge Boston and Shore Railroad; the BW&S was itself a consolidation on December 12, 1883 of the Boston and Point Shirley Railroad and Eastern Junction, Broad Sound Pier and Point Shirley Railroad.
The BW&PS was organized on July 3, 1876 and opened a 3 ft narrow gauge line on June 7, 1877. This line split from the BRB&L at Winthrop Junction and headed east and south for 1.8 miles to Winthrop Center and extended in stages during the following years. In 1881, the part heading south was closed and a new line was built east to Ocean Spray and south to Short Beach; the EJBSP&PS was chartered in 1880 and built a standard gauge railway line from the Eastern Railroad near Crescent Beach southeast via Beachmont and Winthrop Beach to Point Shirley. South of Ocean Spray, this was just east of the BW&PS. Much of this shared section of right-of-way used a dual-gauge track. A branch of the EJBSP&PS was constructed in Revere, from the junction with the Eastern Railroad north to Point of Pines, parallel with the Eastern's Chelsea Beach line; the EJBSP&PS was not operated until 1884, by which time it had been absorbed into the Boston, Winthrop & Shore RR. It operated for only two summers before being abandoned due to damage from storms.
The BW&PS and the EJBSP&PS, along with the Boston & Winthrop were merged late in 1883 and operated thereafter as the Boston, Winthrop & Shore RR. In 1885, after a storm, sections of line were abandoned, the management of the BRB&L stepped in. A circuit or loop line was constructed in 1888 and existed until the 1940 demise of the BRB&L, it used parts of the original alignment of the BW&PS. Most of the line, was built brand new, serving Winthrop Highlands, Winthrop Center and Winthrop Beach; the loop was double-tracked in 1903. The Point Shirley Street Railway was built from Winthrop Beach station to Point Shirley beginning in August 1910 and opened that year; the 1.2-mile single-track line ran along Tafts Avenue. The BRB&L acquired the entire line with legislative approval in October 1912. By 1914, the line operated 30,594 car miles, carried 165,037 passengers, employed seven people. Unusually, the Point Shirley Street Railway did not operate with electric power from overhead lines, it first used a gasoline-powered electric streetcar a battery-powered streetcar owned by the BRB&L, but these did not prove adequate for reliable service and by early 1919 buses were used instead.
This prompted a public outcry with demands for conventional overhead-powered cars. The 1919-built cars proved to be too expensive to operate
A bogie is a chassis or framework that carries a wheelset, attached to a vehicle—a modular subassembly of wheels and axles. Bogies take various forms in various modes of transport. A bogie may remain attached or be detachable. While bogie is the preferred spelling and first-listed variant in various dictionaries and bogy are used. A bogie in the UK, or a railroad truck, wheel truck, or truck in North America, is a structure underneath a railway vehicle to which axles are attached through bearings. In Indian English, bogie may refer to an entire railway carriage. In South Africa, the term bogie is alternatively used to refer to a freight or goods wagon; the first standard gauge British railway to build coaches with bogies, instead of rigidly mounted axles, was the Midland Railway in 1874. Bogies serve a number of purposes: Support of the rail vehicle body Stability on both straight and curved track Improve ride quality by absorbing vibration and minimizing the impact of centrifugal forces when the train runs on curves at high speed Minimizing generation of track irregularities and rail abrasionUsually, two bogies are fitted to each carriage, wagon or locomotive, one at each end.
Another configuration is used in articulated vehicles, which places the bogies under the connection between the carriages or wagons. Most bogies have two axles. Heavy-duty cars may have more than two bogies using span bolsters to equalize the load and connect the bogies to the cars; the train floor is at a level above the bogies, but the floor of the car may be lower between bogies, such as for a bilevel rail car to increase interior space while staying within height restrictions, or in easy-access, stepless-entry, low-floor trains. Key components of a bogie include: The bogie frame: This can be of inside frame type where the main frame and bearings are between the wheels, or of outside frame type where the main frame and bearings are outside the wheels. Suspension to absorb shocks between the bogie frame and the rail vehicle body. Common types are coil springs and rubber airbags. At least one wheelset, composed of an axle with bearings and a wheel at each end; the bolster, the main crossmember, connected to the bogie frame through the secondary suspension.
The railway car is supported at the pivot point on the bolster. Axle box suspensions absorb shocks between the bogie frame; the axle box suspension consists of a spring between the bogie frame and axle bearings to permit up-and-down movement, sliders to prevent lateral movement. A more modern design uses solid rubber springs. Brake equipment: Two main types are used: brake shoes that are pressed against the tread of the wheel, disc brakes and pads. In powered vehicles, some form of transmission electrically powered traction motors or a hydraulically powered torque converter; the connections of the bogie with the rail vehicle allow a certain degree of rotational movement around a vertical axis pivot, with side bearers preventing excessive movement. More modern, bolsterless bogie designs omit these features, instead taking advantage of the sideways movement of the suspension to permit rotational movement; the Commonwealth bogie was manufactured by the English Steel Corporation under licence from the Commonwealth Steel Company in Illinois, United States.
Fitted with SKF or Timken bearings, it was introduced in the late 1950s for all BR Mark 1 vehicles. It was a heavy, cast-steel design weighing about 6.5 long tons, with sealed roller bearings on the axle ends, avoiding the need to maintain axle box oil levels. The leaf springs were replaced by coil springs running vertically rather than horizontally; the advanced design gave a better ride quality than the BR1. The side frame of the bogie was of bar construction, with simple horn guides attached, allowing the axle boxes vertical movements between them; the axle boxes had a cast-steel equaliser bar resting on them. The bar had two steel coil springs placed on it and the bogie frame rested on the springs; the effect was to allow the bar to act as a compensating lever between the two axles and to use both springs to soften shocks from either axle. The bogie had a conventional bolster suspension with swing links carrying a spring plank; the B4 bogie was introduced in 1963. It was a fabricated steel design versus cast iron and was lighter than the Commonwealth, weighing in at 5 long tons.
It had a speed rating of 100 mph. Axle to spring connection was again fitted with roller bearings. However, now two coil springs. Only a small number of Mark 1 stock was fitted with the B4 bogie from new, it being used on the Mark 1 only to replace worn BR1 bogies; the British Rail Mark 2 coach, carried the B4 bogies from new. A heavier-duty version, the B5, was standard on Southern Region Mk1-based EMUs from the 1960s onwards; some Mark 1 catering cars had mixed bogies—a B5 under the kitchen end, a B4 under the seating