|
Lever Frame
Mechanical railway signalling installations rely on lever frames for their operation to interlock the signals, track locks and points to allow the safe operation of trains in the area the signals control. Usually located in the signal box, the levers are operated either by the signalman or the pointsman. The world's largest lever frame is believed to have been in the Spencer Street No.1 signal box in Melbourne, Australia, which had 191 levers, but was decommissioned in 2008. The largest, currently operational, lever frame is located at Severn Bridge Junction in Shrewsbury, England, and has 180 levers; although most of them have now been taken out of use. Overview The lever frame is located in the signal box, which can be a building at ground level or a tower, separated from or connected to an existing station building. Early lever frames were also built as ''ground frames'' next to the track, without any form of shelter and were usually operated by traincrew and not pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Advantage
Mechanical advantage is a measure of the force amplification achieved by using a tool, mechanical device or machine system. The device trades off input forces against movement to obtain a desired amplification in the output force. The model for this is the ''law of the lever.'' Machine components designed to manage forces and movement in this way are called mechanisms. An ideal mechanism transmits power without adding to or subtracting from it. This means the ideal machine does not include a power source, is frictionless, and is constructed from rigid bodies that do not deflect or wear. The performance of a real system relative to this ideal is expressed in terms of efficiency factors that take into account departures from the ideal. Lever The lever is a movable bar that pivots on a fulcrum attached to or positioned on or across a fixed point. The lever operates by applying forces at different distances from the fulcrum, or pivot. The location of the fulcrum deter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isle Of Wight Steam Railway
The Isle of Wight Steam Railway is a heritage railway on the Isle of Wight. The railway passes through of countryside from to station, passing through the small village of Havenstreet, where the line has a station, headquarters and a depot. At Smallbrook Junction, the steam railway connects with the Island Line. Operation The railway is owned and operated by the Isle of Wight Railway Co. Ltd. and run largely by volunteers. Services are operated on most days from June to September, together with selected days in April, May, and October and public holidays. The railway is popular with tourists, attracting people to its original steam locomotive and railway cafe. Over each August Bank Holiday weekend, the railway organises the Island Steam Show, which combines an intensive service on the railway with displays of various sorts of steam power including traction engines and steam fair equipment, together with other attractions that vary year by year. For events like steam galas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continental Europe
Continental Europe or mainland Europe is the contiguous continent of Europe, excluding its surrounding islands. It can also be referred to ambiguously as the European continent, – which can conversely mean the whole of Europe – and, by some, simply as the Continent. When Eurasia is regarded as a single continent, Europe is treated as a subcontinent, and called as European subcontinent. The old notion of Europe as a cultural term was centred on core Europe (''Kerneuropa''), the continental territory of the historical Carolingian Empire, corresponding to modern France, Italy, German-speaking Europe and the Benelux states (historical Austrasia). This historical core of "Carolingian Europe" was consciously invoked in the 1950s as the historical ethno-cultural basis for the prospective European integration (see also Multi-speed Europe). Usage The most common definition of Mainland Europe excludes these continental islands: the Greek Islands, Cyprus, Malta, Sicil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saxby & Farmer
John Saxby (17 August 1821 – 22 April 1913) was an English engineer from Brighton, noted for his work in railway signalling and the invention of the interlocking system of points and signals. He was later a partner in the firm Saxby and Farmer. He is regarded as "the father of modern signalling".Saxby & Farmer on Polunnio Biography Saxby was born at Brighton on 17 August 1821 and in 1834 was apprenticed at the age of thirteen to a carpenter and joiner. In 1840 he was employed as a carpenter at the of the |
Open-loop Controller
In control theory, an open-loop controller, also called a non-feedback controller, is a control system in which the control action is independent of the "process output", which is the process variable that is being controlled."Feedback and control systems" - JJ Di Steffano, AR Stubberud, IJ Williams. Schaums outline series, McGraw-Hill 1967 It does not use feedback to determine if its output has achieved the desired goal of the input command or process setpoint. There are many open-loop controls, such as on/off switching of valves, machinery, lights, motors or heaters, where the control result is known to be approximately sufficient under normal conditions without the need for feedback. The advantage of using open-loop control in these cases is the reduction in component count and complexity. However, an open-loop system cannot correct any errors that it makes or correct for outside disturbances, and cannot engage in machine learning, unlike a closed-loop control system. Open- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Counter-electromotive Force
Counter-electromotive force (counter EMF, CEMF, back EMF),Graf, "counterelectromotive force", Dictionary of Electronics is the electromotive force (EMF) manifesting as a voltage that opposes the change in current which induced it. CEMF is the EMF caused by electromagnetic induction. Details For example, the voltage appearing across an inductor or coil is due to a change in current which causes a change in the magnetic field within the coil, and therefore the self-induced voltage. The polarity of the voltage at every moment opposes that of the change in applied voltage, to keep the current constant. The term ''back electromotive force'' is also commonly used to refer to the voltage that occurs in electric motors where there is relative motion between the armature and the magnetic field produced by the motor's field coils or permanent magnet field, thus also acting as a generator while running as a motor. This effect is not due to the motor's inductance, which generates a voltage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.svg "Click for more on -> Continental Europe")
