| Diesel Multiple Unit |
Article Index for Diesel |
Shopping Diesel |
Website Links For Diesel |
Information AboutDiesel Multiple Unit |
| CATEGORIES ABOUT DIESEL MULTIPLE UNIT | |
| multiple units | |
| rolling stock | |
| rail transport | |
|
in Poznań , Poland ]] DEMU capable of up to 200km/h provides a passenger service between Perth, Western Australia and the mining town of Kalgoorlie ]] A Diesel Multiple Unit or '''DMU''' is a Multiple Unit train consisting of multiple carriages powered by one or more on-board Diesel Engine s. They may also be referred to as a Railcar or Railmotor depending on country. DESIGN The diesel engine may be located above the frame in an engine bay or under the floor. Driving controls can be provided at each end of the car, at one end only, or totally omitted, giving pure 'trailer' cars that still have motors which rely on cab cars for control. TYPES DMU of Class 628 ]] DMUs are usually classified by the method of transmitting motive power to their wheels. Diesel Mechanical In a Diesel Mechanical Multiple Unit the rotating energy of the engine is transmitted via a Gearbox and driveshaft directly to the wheels of the train, much like a car. The transmissions can be shifted manually by the driver, but in most applications gears are changed automatically. Diesel Hydraulic In a Diesel Hydraulic Multiple Unit, a hydraulic Torque Converter , a type of fluid coupling, acts as the transmission medium for the motive power of the diesel engine to turn the wheels. Some units feature a hybrid mix of hydraulic and mechanical transmissions, usually reverting the latter at higher operating speeds as this decreases engine RPM and noise. Diesel Electric In a Diesel Electric Multiple Unit (DEMU) a Diesel Engine drives an Electrical Generator which produces Electrical Energy . This current is then be fed to electric traction motors on the wheels or bogies in the same was as a conventional Diesel Electric Locomotive . In most modern DEMUs, each car is entirely self-contained and has its own engine, generator and electric motors. In older designs some cars within the consist may be entirely unpowered or only feature electric motors, obtaining electrical current from other cars in the consist which have a generator and engine. Direct-drive diesel locomotives often require an impractical number of gears to keep the engine within its powerband; coupling the diesel to a generator eliminates this problem. Power still needs to be transmitted to the generator or alternator via a simple gearbox but this is advantageous because;
DMU of Class 628 ]] DMUs connected]] BENEFITS DMUs connected]] A train composed of DMU cars scales well as it allows extra passenger capacity to be added at the same time as motive power. It also permits passenger capacity to be matched to demand, and for trains to be split and joined en-route. Distribution of the propulsion among the cars also results in a system that is less vulnerable to single-point-of-failure outages. Many classes of DMU are capable of operating with faulty units still in the consist. Because of the self contained nature of diesel engines, there is no need to run Overhead Electric Lines or Electrified Track , which can result in lower system construction costs. AROUND THE WORLD North America Rail Diesel Car RDC-1 #407 of the Cape May Seashore Lines ]] Tri-Rail Bi-Level DMU.]] Talent low-floor DMUs on the O-Train prototype line in Ottawa Canada ]] One of the first Diesel Multiple Units in North America was the Budd Rail Diesel Car (RDC). The RDC was a single passenger car with two diesel engines and two sets of controls. Any number of cars could be connected together and all the propulsion systems controlled from a single operator's station or cab. Introduced in the early 1940s, the cars were used on rural railway lines that did not warrant full passenger trains, or short commuter services. In the United States Of America only heavyweight DMU systems are permitted on freight rail corridors. This is due to the Federal Railway Administration setting higher buff strength requirements than European regulators, effectively prohibited the use of lightweight European-style Light-rail DMUs on main line railways. Several rail operators in the United States use DMUs suitable for mainline use:
Canada generally follows similar buff strength requirements to the USA, but new services are evaluated on a case-by-case basis. As a result several types of lightweight DMUs have been used:
Australia 's 3100-class diesel-electric railcars operating in Adelaide , South Australia ]] See Also: Rail transport in Australia DMUs were first introduced to Australia in the early 20th century for use on quiet branchlines that could not justify a locomotive hauled service. Today a range of modern DMUs are extensively used across Australia for both commuter and intercity routes:
Germany DMU near Rostock]] The Flying Hamburger of Germany , introduced 1933 , established the then-time fastest regular railway connection of the world. Top speed was 160 km/h, the average speed being 124 km/h on the tracks between Berlin and Hamburg . The Trans Europ Express travelled international traffic between countries like Germany, France, Italy, Netherlands in the 1950s and 1960s. They were diesel multiple units since the electrical systems varied a lot. Also from Germany is the CargoSprinter concept. With two motorized units and three flatbed wagons between them, this DMU Container train tried to compete with container road trucks by profiting from existing railway access to factories and businesses, but eliminating the need for inflexible locomotive-pulled cargo trains. The payload was 160 tons. Suffering from technical problems and failing political support for short-haul cargo railway connections, the prototypes were sold to Austria. United Kingdom , once the most popular DMU on British railways]] DMUs have been widely used in the United Kingdom since their introduction in the mid-1950s by British Rail . At that time there was an urgent need to move away from expensive steam traction which led to many experimental designs using diesel propulsion and Multiple Unit s. Today apart from from express journeys, DMUs have become the mainstay of UK passenger operations. One of the first and most successful designs was the Class 101 which entered service in 1956 and remained in mainstream use until 2003. Several hundred were constructed and many similar units followed, such as the Class 121 . Diesel Electric Multiple Units were also developed during the 1950s and 60s as a stop-gap to cover lines that were shortly to be electrified. Of Class 205 and 207 , they were nick-named "Thumpers" by their characteristic sound. The British Rail "InterCity 125" was a much more powerful DEMU introduced in the 1970s. These trains have always run with 2 power cars and between 5 and 9 intermediate coaches. Although originally classified as DEMUs, the coaches were modified from loco-hauled stock, and the power cars were later renumbered as locomotives under Class 43 . , the best selling DMU of the last 10 years in the UK.]] In total, around 30 different DMU types were operating by the 1980s, which lead to spiralling costs with many non-standard units in operation. In order to cut costs British Rail decided to rationalise its DMUs in the 1980s, so called "Sprinterisation" and the older first generation DMUs were replaced by several standardised families:
Following the Privatisation Of British Rail in the late 90s, several other DMU families have been introduced:
There has also been a resurgence in Diesel Electric Multiple Units, with the introduction of the high speed Class 220 Voyager , 221 Super-Voyager and 222 Meridian/Pioneer units. Ireland , 2006]] See Also: Multiple Units of Ireland In the Republic Of Ireland the Córas Iompair Éireann (CIE), which controlled the republic's railways between 1945-86, mainly used locomotives and hauled stock for its passenger trains. Since 1987, Iarnród Éireann (IE) have been increasing the use of this type of train, in order to replace older locomotives and carriages. In Northern Ireland the Northern Ireland Railways used DMUs extensively throughout its system, notably the NIR 80 Class introduced in the early 1970s and currently being replaced (as of 2007). South Korea ( Commute Diesel Car ) serves Tonggeun trains. The NDC and CDC can reach speeds up to 100 km/h and are not used for mountainous lines such as the Taebaek Line. Japan In Japan , Railway s are a major means of passenger Transportation , especially for mass and high-speed transport between major cities and for commuter transport in Metropolitan Area s. Seven Japan Railway companies, state-owned until 1987, cover most parts of Japan. There are also railway services operated by private rail companies, regional governments, and companies funded by both regional governments and private companies. Japanese trains are also famous for always being on time. Five stations ( Shinjuku Station , Ikebukuro Station , Shibuya Station , Umeda Station , and Yokohama Station ) serve more than 2 million passengers each on an average day, making Japan the most railway using nation per capita (see Rail Usage Statistics By Country ). Both DMUs and EMUs are widely used on urban lines, Metro services and for local services in many parts of the country. The development of Japan in the 20th century is analogous to that of its rail transport. Throughout the times, railway was the most important means of transportation in the country, and it still is in larger cities. As many of Japanese suburban cities were developed by railway operators, its unchallenged importance is something unique among the world. GALLERY |
Image:222 Passing Through LoughboroughjpgA Four-car
| "http://wwwinformationdelightinfo/information/entry/Midland_Mainline" class="copylinks">Midland Mainline Class 222 passing through Loughborough on 19 November 2005 , one of the latest DEMUs to see service in the UK |
|
Image:Virgin Voyager On King Edward VII Bridge 2005-10-08jpgA
| "http://wwwinformationdelightinfo/information/entry/Virgin_Trains" class="copylinks">Virgin Trains Class 221 , their replacement for the HST and used on cross-country services |
|
Image:Red Japanese DMUjpg
| "http://wwwinformationdelightinfo/information/entry/Japan" class="copylinks">Japan ese DMU "KIHA40" |
|
Image:Buffel Zwollejpg
| "http://wwwinformationdelightinfo/information/entry/Netherlands" class="copylinks">Dutch DMU "DM '90" or " Buffel " |
|
Image:Lint InterieurjpgInterior Of A
| "http://wwwinformationdelightinfo/information/entry/LINT" class="copylinks">LINT train |
|
Image:DMU In Vilnius DepotjpgA Former
| "http://wwwinformationdelightinfo/information/entry/Soviet" class="copylinks">Soviet , now Lithuania n DMU in a Vilnius depot |
|
Image:Talent Enschedejpg
| "http://wwwinformationdelightinfo/information/entry/Germany" class="copylinks">German DMU " Talent " |
|
Image:OttawaO-TrainInteriorjpgThe Interior Of An
| "http://wwwinformationdelightinfo/information/entry/Canadian" class="copylinks">Canadian O-Train ’s carriage |
|
Image:Fuehrerstand 928676 2004-12-09JPGThe Cab Of A
| "http://wwwinformationdelightinfo/information/entry/Germany" class="copylinks">German DMU of Class 6284 origin |
|
|
|