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57-692: Gap Fire may refer to: Summit Tunnel Fire - A 1984 train fire in the Summit Tunnel on the Greater Manchester / West Yorkshire border. Summit Fire (2008) - A 2008 wildfire in the Santa Cruz Mountains Summit Fire (2013) - A 2013 wildfire in Riverside County Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with

114-436: A dangerous goods train caught fire while passing through the Summit Tunnel on the railway line between Littleborough and Todmorden on the Greater Manchester / West Yorkshire border, England. The tunnel, which is 2,885 yards (2,638 m) in length, was built in 1840–41. Twelve of the fourteen construction shafts were left open to help vent smoke and steam from the locomotives that passed through it. The incident

171-415: A gland ) that covers the inside and outside edges of the bearing race to keep the grease from escaping. Bearings may also be packed with other materials. Historically, the wheels on railroad cars used sleeve bearings packed with waste or loose scraps of cotton or wool fiber soaked in oil, then later used solid pads of cotton. Bearings can be lubricated by a ring oiler , a metal ring that rides loosely on

228-703: A plain bearing ; this underlies speculation that cultures such as the Ancient Egyptians used roller bearings in the form of tree trunks under sleds. There is no evidence for this sequence of technological development. The Egyptians' own drawings in the tomb of Djehutihotep show the process of moving massive stone blocks on sledges as using liquid-lubricated runners which would constitute plain bearings. There are also Egyptian drawings of plain bearings used with hand drills . Wheeled vehicles using plain bearings emerged between about 5000 BC and 3000 BC . A recovered example of an early rolling-element bearing

285-435: A bearing into a bore or onto a shaft, it's important to keep the housing bore and shaft outer diameter to very close limits, which can involve one or more counterboring operations, several facing operations, and drilling, tapping, and threading operations. Alternatively, an interference fit can also be achieved with the addition of a tolerance ring . The service life of the bearing is affected by many factors not controlled by

342-438: A company to produce his innovation. Over a century, the company grew to make bearings of all types, including specialty steel bearings and an array of related products and services. Erich Franke invented and patented the wire race bearing in 1934. His focus was on a bearing design with a cross-section as small as possible and which could be integrated into the enclosing design. After World War II, he founded with Gerhard Heydrich

399-423: A different principle: The following table summarizes the notable characteristics of each of these bearing types. Reducing friction in bearings is often important for efficiency, to reduce wear and to facilitate extended use at high speeds and to avoid overheating and premature failure of the bearing. Essentially, a bearing can reduce friction by virtue of its shape, by its material, or by introducing and containing

456-706: A discrete device); or it may be a layer of bearing metal either fused to the substrate (semi-discrete) or in the form of a separable sleeve (discrete). With suitable lubrication, plain bearings often give acceptable accuracy, life, and friction at minimal cost. Therefore, they are very widely used. However, there are many applications where a more suitable bearing can improve efficiency, accuracy, service intervals, reliability, speed of operation, size, weight, and costs of purchasing and operating machinery. Thus, many types of bearings have varying shapes, materials, lubrication, principle of operation, and so on. There are at least 6 common types of bearing, each of which operates on

513-490: A fluid between surfaces or by separating the surfaces with an electromagnetic field. Combinations of these can even be employed within the same bearing. An example is where the cage is made of plastic, and it separates the rollers/balls, which reduce friction by their shape and finish. Bearing design varies depending on the size and directions of the forces required to support. Forces can be predominately radial , axial ( thrust bearings ), or bending moments perpendicular to

570-464: A groove in the axle assembly. Bearings played a pivotal role in the nascent Industrial Revolution , allowing the new industrial machinery to operate efficiently. For example, they were used for holding wheel and axle assemblies to greatly reduce friction compared to prior non-bearing designs. The first patent for a radial-style ball bearing was awarded to Jules Suriray , a Parisian bicycle mechanic, on 3 August 1869. The bearings were then fitted to

627-401: A hole. Lubrication is used to reduce friction. Lubricants come in different forms, including liquids, solids, and gases. The choice of lubricant depends on the specific application and factors such as temperature, load, and speed. In the ball bearing and roller bearing , to reduce sliding friction, rolling elements such as rollers or balls with a circular cross-section are located between

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684-476: A laminated metal backing. The PTFE liner offers consistent, controlled friction as well as durability, whilst the metal backing ensures the composite bearing is robust and capable of withstanding high loads and stresses throughout its long life. Its design also makes it lightweight-one tenth the weight of a traditional rolling element bearing. There are many methods of mounting bearings, usually involving an interference fit . When press fitting or shrink fitting

741-1078: A rotating component. Examples include ultra high-speed bearings in dental drills, aerospace bearings in the Mars Rover, gearbox and wheel bearings on automobiles, flexure bearings in optical alignment systems, and air bearings used in coordinate-measuring machines . Common motions permitted by bearings are: The first plain and rolling-element bearings were wood , closely followed by bronze . Over their history, bearings have been made of many materials, including ceramic , sapphire , glass , steel , bronze , and other metals. Plastic bearings made of nylon , polyoxymethylene , polytetrafluoroethylene , and UHMWPE , among other materials, are also in use today. Case Hardening Steel SAE 4118 High Alloy Steel M50NiL Watchmakers produce "jeweled" watches using sapphire plain bearings to reduce friction, thus allowing more precise timekeeping. Even basic materials can have impressive durability. Wooden bearings, for instance, can still be seen today in old clocks or in water mills where

798-484: A type of linear motion bearing consisting of both an external and internal 90-degree vee angle. In the early 1980s, Pacific Bearing's founder, Robert Schroeder, invented the first bi-material plain bearing that was interchangeable with linear ball bearings. This bearing had a metal shell (aluminum, steel or stainless steel) and a layer of Teflon-based material connected by a thin adhesive layer. Today's ball and roller bearings are used in many applications, which include

855-446: A world-leading center for ball bearing production. The modern, self-aligning design of ball bearing is attributed to Sven Wingquist of the SKF ball-bearing manufacturer in 1907 when he was awarded Swedish patent No. 25406 on its design. Henry Timken , a 19th-century visionary and innovator in carriage manufacturing, patented the tapered roller bearing in 1898. The following year he formed

912-618: Is a small collection of photographs noting the fire, along with the statistics of the construction, and a quotation by George Stephenson , the tunnel's builder, who said, "I stake my reputation and my head that the tunnel will never fail so as to injure any human life". A public enquiry was held into the accident. The hearing was held in Manchester . A report was published on 4 June 1985. 53°40′30″N 2°05′18″W  /  53.6751°N 2.088261°W  / 53.6751; -2.088261 Bearing (mechanical) The term "bearing"

969-553: Is a wooden ball bearing supporting a rotating table from the remains of the Roman Nemi ships in Lake Nemi , Italy . The wrecks were dated to 40 BC. Leonardo da Vinci incorporated drawings of ball bearings in his design for a helicopter around the year 1500; this is the first recorded use of bearings in an aerospace design. However, Agostino Ramelli is the first to have published roller and thrust bearings sketches. An issue with

1026-435: Is commonly used in large and complex internal combustion engines in parts of the engine where directly splashed oil cannot reach, such as up into overhead valve assemblies. High-speed turbochargers also typically require a pressurized oil system to cool the bearings and keep them from burning up due to the heat from the turbine. Composite bearings are designed with a self-lubricating polytetrafluorethylene (PTFE) liner with

1083-410: Is derived from the verb " to bear "; a bearing being a machine element that allows one part to bear (i.e., to support) another. The simplest bearings are bearing surfaces , cut or formed into a part, with varying degrees of control over the form, size, roughness , and location of the surface. Other bearings are separate devices installed into a machine or machine part. The most sophisticated bearings for

1140-422: Is determined by load, temperature, maintenance, lubrication, material defects, contamination, handling, installation and other factors. These factors can all have a significant effect on bearing life. For example, the service life of bearings in one application was extended dramatically by changing how the bearings were stored before installation and use, as vibrations during storage caused lubricant failure even when

1197-439: Is due to the strain of the ball and race. With fluid bearings, it is due to how the pressure of the fluid varies with the gap (when correctly loaded, fluid bearings are typically stiffer than rolling element bearings). Some bearings use a thick grease for lubrication, which is pushed into the gaps between the bearing surfaces, also known as packing . The grease is held in place by a plastic, leather, or rubber gasket (also called

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1254-464: The ballast beneath the other track in the tunnel, so they left the train and ran the remaining mile to the south portal (where they knew there was a direct telephone connection to the signalman) to raise the alarm. Crews from Greater Manchester Fire Brigade and West Yorkshire Fire Brigade quickly attended the scene. Co-ordination between the brigades appears to have worked well, perhaps because they had both participated in an emergency exercise in

1311-411: The ventilation shafts to provide a water supply. At the same time, crews from West Yorkshire fire brigade entered the tunnel and began fighting fires in the ballast at the north end of the train. However, at 9.40 a.m., the pressure in one of the heated tankers rose high enough to open its pressure relief valves. The vented vapour caught fire and blew flames onto the tunnel wall. The wall deflected

1368-548: The North West of England in less than three weeks led the Littleborough and Saddleworth MP Geoffrey Dickens to call for an inquiry into railway safety, in particular with respect to the conveyance of dangerous chemicals such as those involved in the accidents at Eccles and Summit Tunnel. The train involved was the 01:40 freight train from Haverton Hill , Teesside to Glazebrook oil distribution terminal near Warrington . It

1425-416: The air outside. At the height of the fire, pillars of flame approximately 150 metres (490 ft) high rose from the shaft outlets on the hillside above. The gases are estimated to have flowed up these shafts at 50 metres per second (110 mph). Air at this speed is capable of blowing around heavy items: hot projectiles made from tunnel lining (rather like lava bombs from a volcano ) were cast out over

1482-423: The applied load changes. One source of motion is gaps or "play" in the bearing. For example, a 10 mm shaft in a 12 mm hole has 2 mm play. Allowable play varies greatly depending on the use. As an example, a wheelbarrow wheel supports radial and axial loads. Axial loads may be hundreds of newtons force left or right, and it is typically acceptable for the wheel to wobble by as much as 10 mm under

1539-440: The ball and roller bearings is that the balls or rollers rub against each other, causing additional friction. This can be reduced by enclosing each individual ball or roller within a cage. The captured, or caged, ball bearing was originally described by Galileo in the 17th century. The first practical caged-roller bearing was invented in the mid-1740s by horologist John Harrison for his H3 marine timekeeper. In this timepiece,

1596-521: The bearing manufacturers. For example, bearing mounting, temperature, exposure to external environment, lubricant cleanliness, and electrical currents through bearings . High frequency PWM inverters can induce electric currents in a bearing, which can be suppressed by the use of ferrite chokes . The temperature and terrain of the micro-surface will determine the amount of friction by touching solid parts. Certain elements and fields reduce friction while increasing speeds. Strength and mobility help determine

1653-446: The bearing. A second source of motion is elasticity in the bearing itself. For example, the balls in a ball bearing are like stiff rubber and under load deform from a round to a slightly flattened shape. The race is also elastic and develops a slight dent where the ball presses on it. The stiffness of a bearing is how the distance between the parts separated by the bearing varies with the applied load. With rolling element bearings, this

1710-421: The bottom, with gears partially immersed in the liquid, or crank rods that can swing down into the pool as the device operates. The spinning wheels fling oil into the air around them, while the crank rods slap at the surface of the oil, splashing it randomly on the engine's interior surfaces. Some small internal combustion engines specifically contain special plastic flinger wheels which randomly scatter oil around

1767-456: The caged bearing was only used for a very limited oscillating motion, but later on, Harrison applied a similar bearing design with a true rotational movement in a contemporaneous regulator clock. The first patent on ball bearings was awarded to Philip Vaughan , a British inventor and ironmaster in Carmarthen in 1794. His was the first modern ball-bearing design, with the ball running along

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1824-408: The central rotating shaft of the bearing. The ring hangs down into a chamber containing lubricating oil. As the bearing rotates, viscous adhesion draws oil up the ring and onto the shaft, where the oil migrates into the bearing to lubricate it. Excess oil is flung off and collects in the pool again. A rudimentary form of lubrication is splash lubrication . Some machines contain a pool of lubricant in

1881-445: The company Franke & Heydrich KG (today Franke GmbH) to push the development and production of wire race bearings. Richard Stribeck's extensive research on ball bearing steels identified the metallurgy of the commonly used 100Cr6 (AISI 52100), showing coefficient of friction as a function of pressure. Designed in 1968 and later patented in 1972, Bishop-Wisecarver's co-founder Bud Wisecarver created vee groove bearing guide wheels,

1938-432: The duration by which ten percent of the bearings in that application can be expected to have failed due to classical fatigue failure (and not any other mode of failure such as lubrication starvation, wrong mounting etc.), or, alternatively, the duration at which ninety percent will still be operating. The L10/B10 life of the bearing is theoretical, and may not represent service life of the bearing. Bearings are also rated using

1995-415: The fire brigades forced high-expansion foam into ventilation shafts far from the fire. This created blockages that starved the fire of oxygen. By mid-afternoon the next day, the inferno was no longer burning, though the fire was by no means knocked down. Petrol continued to leak from the derailed wagons through the tunnel drainage and ballast and the vapour sporadically reignited when it came into contact with

2052-405: The fire was extinguished, and 809,000 litres (178,000 imp gal; 214,000 US gal) (670 tonnes or 660 long tons or 740 short tons) burnt. The damage done by the fire was minimal. Approximately half a mile of track had to be replaced, as did all the electrical services and signalling. The biggest surprise was how well the brick lining had stood up to the fire. Although some bricks in

2109-428: The flames both ways along the tunnel, and the bricks in the tunnel wall began to spall and melt in the flames. The BA crews from both brigades decided to evacuate. They managed to leave just before the first explosion rocked the tunnel. The firefighters were saved because blast relief shafts 8 and 9 acted as flame vents (a function their designer never envisaged). Left to itself, the fire burned as hot as it could. As

2166-457: The hillside. These set much of the vegetation on fire, and caused the closure of the A6033 road . In the cleanup operation afterwards, small globules of metal were found on the ground surrounding shaft 9; these had been melted from the tanker walls, swept up with the exhaust gases, and dropped out onto the grass around the top of the shaft. Unable to get close enough to safely fight the fire directly,

2223-449: The hot tunnel lining. Two hundred people were evacuated from their homes and workplaces in Walsden in response. They were allowed back home the next day. The brigades continued to fight the fire for another two days, until West Yorkshire Fire Brigade issued the stop message just after 6:30 p.m. on Christmas Eve. Fire crews remained at the site until 7 January 1985. Due to the fire,

2280-480: The interior of the mechanism. For high-speed and high-power machines, a loss of lubricant can result in rapid bearing heating and damage due to friction. Also, in dirty environments, the oil can become contaminated with dust or debris, increasing friction. In these applications, a fresh supply of lubricant can be continuously supplied to the bearing and all other contact surfaces, and the excess can be collected for filtration, cooling, and possibly reuse. Pressure oiling

2337-504: The line between Rochdale and Todmorden was closed. Passenger trains between two stations were replaced by buses. Of the 1,100,000 litres (240,000 imp gal; 290,000 US gal) of petrol carried by the train, 275,000 litres (60,000 imp gal; 73,000 US gal) were rescued by the train crew when they drove the locomotive and the first three tankers to safety. A further 16,000 litres (3,500 imp gal; 4,200 US gal) of petrol were recovered after

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2394-491: The load the bearing type can carry. Alignment factors can play a damaging role in wear and tear, yet overcome by computer aid signaling and non-rubbing bearing types, such as magnetic levitation or air field pressure. Fluid and magnetic bearings can have practically indefinite service lives. In practice, fluid bearings support high loads in hydroelectric plants that have been in nearly continuous service since about 1900 and show no signs of wear. Rolling element bearing life

2451-778: The main axis. Different bearing types have different operating speed limits. Speed is typically specified as maximum relative surface speeds, often specified ft/s or m/s. Rotational bearings typically describe performance in terms of the product DN where D is the mean diameter (often in mm) of the bearing and N is the rotation rate in revolutions per minute. Generally, there is considerable speed range overlap between bearing types. Plain bearings typically handle only lower speeds, rolling element bearings are faster, followed by fluid bearings and finally magnetic bearings which are limited ultimately by centripetal force overcoming material strength. Some applications apply bearing loads from varying directions and accept only limited play or "slop" as

2508-418: The most demanding applications are very precise components; their manufacture requires some of the highest standards of current technology. Rotary bearings hold rotating components such as shafts or axles within mechanical systems and transfer axial and radial loads from the source of the load to the structure supporting it. The simplest form of bearing, the plain bearing , consists of a shaft rotating in

2565-487: The only load on the bearing was its own weight; the resulting damage is often false brinelling . Bearing life is statistical: several samples of a given bearing will often exhibit a bell curve of service life, with a few samples showing significantly better or worse life. Bearing life varies because microscopic structure and contamination vary greatly even where macroscopically they seem identical. Bearings are often specified to give an "L10" (US) or "B10" (elsewhere) life,

2622-407: The races or journals of the bearing assembly. A wide variety of bearing designs exists to allow the demands of the application to be correctly met for maximum efficiency, reliability, durability, and performance. It is sometimes assumed that the invention of the rolling bearing, in the form of wooden rollers supporting– or bearing –an object being moved, predates the invention of a wheel rotating on

2679-518: The title Summit Fire . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Summit_Fire&oldid=745534771 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Summit Tunnel Fire The Summit Tunnel fire occurred on 20 December 1984, when

2736-434: The tunnel a month before. The train crew were persuaded to return to the train, where they uncoupled the three tankers still on the rails and used the locomotive to drive them out. Greater Manchester fire brigade then loaded firefighting equipment onto track trolleys and sent a crew with breathing apparatus (BA) in to begin their firefighting operation at the south end of the train. They also lowered hose lines down one of

2793-405: The tunnel and in the blast relief shafts had become so hot that they vitrified and ran like molten glass, most of the brickwork lining of the tunnel was scorched but still serviceable. One of the photographs taken in the aftermath shows a rail tanker directly beneath shaft 9: it is crowned with a mass of vitrified slag from bricks in the shaft that had melted and dripped down. The last of the wagons

2850-407: The varying load. In contrast, a lathe may position a cutting tool to ±0.002 mm using a ball lead screw held by rotating bearings. The bearings support axial loads of thousands of newtons in either direction and must hold the ball lead screw to ±0.002 mm across that range of loads Stiffness is the amount that the gap varies when the load on the bearing changes, distinct from the friction of

2907-506: The walls warmed up and the air temperature in the tunnel rose, all 10 tankers discharged petrol vapour from their pressure relief valves. Two tankers melted (at approximately 1,530 °C or 2,790 °F) and discharged their remaining loads. The fuel supply to the fire was so rich that some of the combustibles were unable to find oxygen inside the tunnel with which to burn; they were instead ejected from vent shafts 8 and 9 as fuel-rich gases that burst into flame when they encountered oxygen in

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2964-413: The water provides cooling and lubrication. By far, the most common bearing is the plain bearing , a bearing that uses surfaces in rubbing contact, often with a lubricant such as oil or graphite. A plain bearing may or may not be a discrete device. It may be nothing more than the bearing surface of a hole with a shaft passing through it, or of a planar surface that bears another (in these cases, not

3021-452: The way through the tunnel, a defective axle bearing ( journal bearing ) derailed the fourth tanker, which caused the derailment of those behind. Only the locomotive and the first three tankers remained on the rails. One of the derailed tankers fell on its side and began to leak petrol into the tunnel. Vapour from the leaking petrol was probably ignited by the damaged axle box . The three train crew members could see fire spreading through

3078-461: The winning bicycle ridden by James Moore in the world's first bicycle road race, Paris-Rouen , in November 1869. In 1883, Friedrich Fischer , founder of FAG , developed an approach for milling and grinding balls of equal size and exact roundness by means of a suitable production machine, which set the stage for the creation of an independent bearing industry. His hometown Schweinfurt later became

3135-465: Was formed by class 47 diesel locomotive 47 125 and thirteen tankers . At 05:50 on 20 December 1984, the train, carrying more than 1,000,000 litres (220,000 imp gal; 260,000 US gal) (835 tonnes or 822 long tons or 920 short tons) of four-star petrol in thirteen tankers , entered the tunnel on the Yorkshire (north) side traveling at 40 miles per hour (64 km/h). One-third of

3192-473: Was one of a series of British railway accidents during 1984, coming only days after the fatal collision between an express passenger train and a train of fuel oil tankers at Eccles , Greater Manchester on 4 December. One day earlier on 3 December a train guard had been killed after a collision between a diesel multiple unit and parcels vans at Longsight also in Manchester. This third serious railway accident in

3249-518: Was removed from the tunnel on 1 March 1985. Once British Rail had replaced the track and electrical services, shored up the bases of vent shafts 8 and 9 and filled the two shafts with inert foam (all this took eight months), locals were allowed a once-in-a-lifetime opportunity to walk through the tunnel before train services resumed on 19 August 1985. At the Masons Arms public house in Todmorden, there

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