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Show New Type of Locomotive. , A locomotive with tho Stumpf l:i system of cylinders and valves for t direct flow -.t steam has been built for the Northeastern lt-tiiway, Eng- ; land, and is an Interesting novelty in locomotive deslg.-is, although a few locomotives of this type -re in u.e j in other' European countries. In the ordinary locomotlvo steam en- , terlng at cither ond f the cylinder j follows the piston in Its stroke and then (as the piston makes Its return strokes) tho steam reverses Its mb- tlon, the expanded and partly cooled .' steam being forced out at the samo ; end of the cylinder and through the port which is to be used by the next I inflow of hot steam. ;! In the Stumpf system the exhaust 'ports aro at the middle of the cylinder cylin-der so that this cooling effect is avoided. This arrangement neces- ' sitatcs the use of a long cylinder and a long drum shaped piston. This i system Is claimed to be a satlsfac- j tory substitute for superhcatlns, and !j it Is further claimed that Its steam j consumption is as low as that of a , compond engine. The Northern Railway locomotivo, however, is ' equipped with a superheater. J In tho Northeastern Railway en- glnc tho cylinders arc twenty Inches ( diamotcr and four feet eight inches i j long, with a stroke of twenty-six I inches. The exhaust ports are a J series of holes drilled round the 3 cylindcnjwalls and leading to an an- 3 nular exhaust chamber. The piston l fills approximately half of tho cyl- j Inder volume. In fact, at the end jj of ca,ch stroke one or other of Its y edges Is just clearing the ring of ex- i' haust ports and allowing exhaust to j- tako place. I In this way each half of the cyl- i' Inder volume has to deal with the ?: steam from only ono Inlet port, and J as tho total area of the exhaust port Is large tho period of exhaust .1 extends from a short tlmo before i the end of the stroke until a short j5. time after. The bulk of the one r stroke Is thus occupied with tho ad- . mission and expansion, and the bulk j of the other with the compression 1 of the steam. In general, the period j. of exhaust covers 10 per cent of the j stroke each way, so that admission and expansion occupy 90 per cent of the stroke In one direction and com- ; pression 90 per cent of the stroke in the other direction. i' g '. The pistons aro hollow castings ; with spring rings at each end. Tho H admission of steam Is controlled by 'D piston valves operated by Wal- jfl schacrts valve gear. Tho valves have S inside admission; their maximum H travel is six and one-half inches and ' H their exhaust lap one and three- TJ quarters Inches. When the onglne UE .is running in full gear the valvi ports provide an auxiliary cxhaustf :m but when the onglne is notched upi this auxiliary exhaust Is closed and all the steam escapes by way of the jS central ring of ports. jS |
