The Duewag Y is a series of diesel multiple units (DMUs) manufactured between 1965 and 1988 for Danish rail operators by the

West German West Germany was the common English name for the Federal Republic of Germany (FRG) from its formation on 23 May 1949 until its reunification with East Germany on 3 October 1990. It is sometimes known as the Bonn Republic after its capital c ...

company Waggonfabrik Uerdingen. A total of 160 cars were built: 76

motor cars An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power gene ...

, 23 trailer cars, and 61 control cars. Introduced in 1965 by Danish private operators and later in 1984 by DSB, the Y-type units began being phased out in the 1990s. DSB ceased operations in 2010, and the last run on Danish rails, by a private operator, occurred in 2012. All units were scrapped except one preserved for museum purposes and another exported to Poland in 2008. In 2010, this unit operated in

Kuyavian-Pomeranian Voivodeship * Kuyavian-Pomeranian Voivodeship is one of the 16 voivodeships (provinces) in Poland. * Kuyavian-Pomeranian is one of 13 Polish constituency of the European Parliament. * Kuyavian-Pomeranian Regional Assembly is the regional legislature of t ...

under Arriva RP, but it was later placed in long-term reserve with no plans for reactivation.

History

In the 1960s, Danish private rail operators began retiring

steam locomotives A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, oil or, rarely, wood) to heat water in the locomot ...

on local lines, seeking diesel replacements to cut costs. A consortium of private rail companies agreed to jointly fund a bulk order. After testing various models, they selected Waggonfabrik Uerdingen in

West Germany West Germany was the common English name for the Federal Republic of Germany (FRG) from its formation on 23 May 1949 until German reunification, its reunification with East Germany on 3 October 1990. It is sometimes known as the Bonn Republi ...

for its superior offer. Between 1965 and 1988, 160 Y-type cars – 76

, 23 trailers, and 61 control cars, including 9 motor and 5 control cars with dual cabs – were delivered in eight batches to 14 private operators and DSB. Production occurred at Düwag's

Krefeld Krefeld ( , ; ), also spelled Crefeld until 1925 (though the spelling was still being used in British papers throughout the Second World War), is a city in North Rhine-Westphalia, in western Germany. It is located northwest of Düsseldorf, its c ...

plant, with final assembly by

Scandia Scandza was described as a "great island" by Gothic-Byzantine historian Jordanes in his work ''Getica''. The island was located in the Arctic regions of the sea that surrounded the world. The location is usually identified with Scandinavia. Jor ...

Randers Randers () is a city in Randers Municipality, Central Denmark Region on the Jutland peninsula. It is List of cities and towns in Denmark, Denmark's sixth-largest city, with a population of 64,511 (). Designated ''Y'' to denote private operator stock, the units earned the nickname ''lynette'' ( Danish: ''little lightning'') in colloquial use.

Design

The Y-type

DMUs A diesel multiple unit or DMU is a multiple-unit train powered by on-board diesel engines. A DMU requires no separate locomotive, as the engines are incorporated into one or more of the carriages. Diesel-powered single-unit railcars are also ...

consist of

(Ym, Danish: ''motorvogn''), intermediate trailer cars (Yp, ''mellemvogn''), and control cars (Ys, ''styrevogn''). Configurations range from two to seven cars, with up to five trailers between two cab-equipped cars (at least one motor car). Common setups include two-car (Ym+Ys) and three-car (Ym+Yp+Ys) units.

Body

The cars feature self-supporting steel bodies with welded rolled and bent profile frames. Exterior walls have ribbed steel panels below windows, with steel sheet roofs and corrugated steel floors spot-welded to the frame. Mineral wool fills the space between steel and wooden floors, while mineral and glass wool mats insulate walls and roofs for thermal and acoustic protection.

Interior

Passenger area

Interior layouts vary by operator, affecting seat count, door width, and amenities like toilets. In motor cars, a baggage area behind the cab houses electrical equipment, a sink, a conductor's seat and table, bike racks, and a wheelchair tie-down space, accessed via double inward-opening doors. This leads to a passenger compartment with seats along the sides and a central aisle, overhead luggage racks, an optional toilet with a single door, and an entry vestibule with folding doors over steps. Control cars mirror this layout but replace the baggage area with more passenger space. Trailer cars have vestibules at both ends flanking a similar passenger compartment. Compartment partitions feature single sliding doors with windows. Inter-car gangways use rubber rollers, transition plates, and double inward-opening glazed doors. Windows – double-glazed in walls and doors – are fixed in rubber seals, except for two per compartment, which are two-part with tiltable upper sections. Lighting includes ceiling fluorescent tubes and emergency incandescent lamps, powered at 220 V AC, 100 Hz, via two frequency converters per car. Heating comes from underfloor oil-fired units blowing warm air. A PA system allows cab announcements.

Driver's cab

The cab is accessed via a single sliding door without a window. It features a control desk and an adjustable driver's seat. Front windows use 10 mm (0.39 in) triple-layer glass, while side windows are 6 mm (0.24 in) double-layer curved glass.

Powertrain

Each motor car's two middle axles are driven by diesel engines suspended from the underframe via rubber-metal joint hangers. Power comes from two

diesel Diesel may refer to: * Diesel engine, an internal combustion engine where ignition is caused by compression * Diesel fuel, a liquid fuel used in diesel engines * Diesel locomotive, a railway locomotive in which the prime mover is a diesel engine ...

four-stroke A four-stroke (also four-cycle) engine is an internal combustion (IC) engine in which the piston completes four separate strokes while turning the crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either directio ...

inline-six A straight-six engine (also referred to as an inline-six engine; abbreviated I6 or L6) is a piston engine with six cylinders arranged in a straight line along the crankshaft. A straight-six engine has perfect primary and secondary engine balanc ...

, liquid-cooled engines in a horizontal layout. Early units used Büssing U11-200D engines (143 kW), while later batches had

Daimler-Benz Mercedes-Benz Group AG (formerly Daimler-Benz, DaimlerChrysler, and Daimler) is a Germany, German Multinational corporation, multinational Automotive industry, automotive company headquartered in Stuttgart, Baden-Württemberg, Germany. It is o ...

OM407h engines (162 kW). A

hydro Hydro (from ) may refer to: Energy technologies * Water-derived power or energy: ** Hydropower, derived from water ** Hydroelectricity, in electrical form * "Hydro", AC mains electricity in parts of Canada * Micro hydro, a type of hydroelect ...

mechanical Mechanical may refer to: Machine * Machine (mechanical), a system of mechanisms that shape the actuator input to achieve a specific application of output forces and movement * Mechanical calculator, a device used to perform the basic operations o ...

Voith The Voith Group is a global technology company. With its broad portfolio of systems, products, services and digital applications, Voith trades in the markets of energy, paper, raw materials and transport. Founded in 1867, Voith today has aroun ...

Diwa 506 transmission integrates a hydraulic torque converter with a differential, splitting power between hydraulic and mechanical systems at low to mid speeds, shifting fully to mechanical at higher speeds. Power reaches the

driving wheels On a steam locomotive, a driving wheel is a powered wheel which is driven by the locomotive's pistons (or turbine, in the case of a steam turbine locomotive). On a conventional, non-articulated locomotive, the driving wheels are all coupled tog ...

via a

universal joint A universal joint (also called a universal coupling or U-joint) is a joint or coupling connecting rigid shafts whose axes are inclined to each other. It is commonly used in shafts that transmit rotary motion. It consists of a pair of hinges ...

to a Voith V13 axle gearbox. Direction changes use a reversing mechanism in the transmission.

Bogies

Each car rides on two twin-axle

bogies A bogie ( ) (or truck in North American English) comprises two or more wheelsets (two wheels on an axle), in a frame, attached under a vehicle by a pivot. Bogies take various forms in various modes of transport. A bogie may remain normally ...

with welded H-shaped box frames, supported by metal-rubber leaf springs between the wheels. The bolster rests on coil and rubber springs, with vibrations damped by

anti-roll bars An anti-roll bar (roll bar, anti-sway bar, sway bar, stabilizer bar) is an automobile suspension (vehicle), suspension part that helps reduce the body roll of a vehicle during fast cornering or over road irregularities. It links opposite front or ...

and hydraulic dampers. Wheelsets feature 760 mm (29.9 in) diameter wheels with wavy discs and

disc brakes Disc or disk may refer to: * Disk (mathematics), a two dimensional shape, the interior of a circle * Disk storage * Optical disc * Floppy disk Music * Disc (band), an American experimental music band * ''Disk'' (album), a 1995 EP by Moby Other ...

. All cars have Knorr

air An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...

and hand brakes, with motor and control cars adding an auxiliary air brakes.

Operations

Denmark

Private operators

Y-type trainsets were delivered to 14 Danish private operators. These units were operated by companies such as

Odderbanen The Odder Line (), also known formerly as the Hads-Ning Herreders Jernbane (HHJ), is a long standard-gauge single track (rail), single-track light-rail line which connects the city of Aarhus to the town of Odder in the Central Denmark Region. T ...

, Varde-Nørre Nebel Jernbane,

Lemvigbanen The Lemvig Line ( or ''Vemb-Lemvig-Thyborøn Jernbane'' (''VLTJ'')) is a local railway line in Northwest Jutland, Denmark. Established in 1879, the line extends from Vemb via Lemvig to Thyborøn. The single-track line is mostly level, and is o ...

, Østbanen,

Gribskovbanen The Gribskov Line or the Gribskov Railway () is a local passenger railway line in North Zealand north of Copenhagen, Denmark. The line runs north from Hillerød through the Gribskov forest and splits into two branches to the seaside resort towns ...

, Frederiksværkbanen, Hornbækbanen, Nærumbanen,

Vestsjællands Lokalbaner Vestsjællands Lokalbaner A/S (literally ''The Local Railways of West Zealand (Denmark), Zealand'', abbreviated VL) was a Denmark, Danish railway company. It existed from 2003 to 2009. History A merger of Odsherreds Jernbane, Odsherreds Jernbane ...

, and

Nordjyske Jernbaner Nordjyske Jernbaner (abbreviated NJ) is a Danish railway company operating in Region Nordjylland. The company was formed in 2001 as a merger of Hjørring Privatbaner (HP) and Skagensbanen (SB) and Hirtshalsbanen (HB). Headquartered in Hjørri ...

. The carriages were generally painted orange with a white stripe along the sides, although there were also liveries featuring red, gray, and white, as well as various patterns, as each operator had its own established color scheme. Initially fitted with screw couplers and buffers for mixed passenger-freight trains, they later received automatic couplers when this practice ended. Some units added air conditioning. The final private operator run occurred in late June 2012 by Varde-Nørre Nebel Jernbane, from

Varde Varde is a Danish city in southwestern Jutland and is the primary city in the municipality of Varde, in Region of Southern Denmark. In 2015 municipality changed its motto to "We in nature" to emphasize its rural atmosphere. The town has an old ma ...

to Nobel. Units were scrapped at

Helsingør Helsingør ( , ; ), classically known in English as Elsinore ( ), is a coastal city in northeastern Denmark. Helsingør Municipality had a population of 63,953 on 1 January 2025, making it the 23rd most populated municipality in Denmark. Helsin ...

. In 2025, the Y-train has operated on the VLTJ for more than 40 years.

Danske Statsbaner

DSB began using Y-type units in 1984. Their three- or four-car sets used ''ML''-series motor cars at both ends with one or two ''FL''-series trailers, while nine dual-cab motor cars ran solo, all on the

Hillerød Hillerød () is a Denmark, Danish town with a population of 36,604 (1 January 2025)Helsingør Helsingør ( , ; ), classically known in English as Elsinore ( ), is a coastal city in northeastern Denmark. Helsingør Municipality had a population of 63,953 on 1 January 2025, making it the 23rd most populated municipality in Denmark. Helsin ...

route. In the 1990s, replacement by IC2 and Desiro units began, retiring most Y-types except 1983–1988 models, which were refurbished between 1997 and 1999 at

Hundested Hundested is a town with a population of 8,590 (1 January 2025) and a former municipality ( Danish, '' kommune'') in Region Hovedstaden in the northern part of the island of Zealand (''Sjælland'') in eastern Denmark. The former municipality is su ...

, including new interiors. In 2001, DSB transferred all units to its subsidiary

Hovedstadens Lokalbaner Hovedstadens Lokalbaner () is a Denmark, Danish company formed in 2002 that owns the trains and tracks of several local railways around Copenhagen: Frederiksværkbanen, Gribskovbanen, Hornbækbanen, Lille Nord, Nærumbanen and Østbanen (Denmark), ...

, which ran them until 2006 when

Lokalbanen Lokalbanen A/S (''The Local Railway'', abbreviated LB) was a Danish railway company responsible for train operation and related passenger services on five local railways north of Copenhagen, Denmark. The company was formed in 2001, and merged wit ...

took over with LINT units. Returned to DSB, they were decommissioned in 2010 and scrapped at Helsingør, except for one museum unit and one sent to

Arriva Arriva Ltd. is a British multinational public transport company headquartered in Sunderland, England. The company was originally established on 24 October 1938 as T Cowie Ltd. Initially focused on the sale of motorcycles, it relaunched shortl ...

's Polish branch.

Poland

On 19 June 2007, a PCC Rail Jaworzno and Arriva Polska consortium won a contract to operate non-electrified lines in

from 9 December 2007 to 11 December 2010. Even before the winner of this process was announced, the newly established company Arriva PCC, due to a shortage of rolling stock, decided to purchase used MR/MRD trainsets from Denmark as well as one Y-type trainset. In 2008, Arriva acquired a Y-type unit from DSB – motor car Ym5 (1965), trailer Yp25 (1970), and control car Ys47 (1970) – which underwent a technical review and test runs in Denmark, repairs at Arriva Werke Nord in

Neustrelitz Neustrelitz (; ) is a town in the Mecklenburgische Seenplatte district in the state of Mecklenburg-Vorpommern, Germany. It is situated on the shore of the Zierker See in the Mecklenburg Lake District. From 1738 until 1918 it was the capital o ...

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

, and modernization at the Tabor Railway Vehicle Institute in Poland. Upgrades included SHP, vigilance systems, Radio-Stop, fire sensors, new exterior lighting, seats, and flame-retardant materials, plus a new livery and Polish signage. Approved for service on 19 February 2010, it began test runs on 12 March and regular service on 31 March after driver training in Denmark. The trailer Yp25 was removed in June due to frequent faults, leaving a Ym5+Ys47 configuration. On 27 November, it was showcased at Bydgoszcz Główna for Railwaymen's Day. Retired by late 2010, it entered long-term reserve. Its 80 km/h (50 mph) top speed couldn't meet timetable demands or join Arriva Ekspress cycles. With newer domestic

railbuses A railbus is a lightweight passenger railcar with an automotive engine. It shares many aspects of its construction with a bus, typically having a bus (original or modified) body and four wheels (2 axles) on a fixed base instead of on bogies. O ...

acquired, no reactivation is planned.

References

{{reflist DSB multiple units Diesel multiple units of Poland