Non-Powered Control Unit

A control car, cab car (North America), control trailer, or driving trailer (UK and Ireland) is a non-powered rail vehicle from which a train can be operated. As dedicated vehicles or regular passenger cars, they have one or two driver compartments with all the controls and gauges required to remotely operate the locomotive, including exterior locomotive equipment such as horns, bells, ploughs, and lights. They also have communications and safety systems such as GSM-R or European Train Control System (ETCS). Control cars enable push-pull operation when located on the end of a train opposite its locomotive by allowing the train to reverse direction at a terminus without moving the locomotive or turning the train around.

Control cars can carry passengers, baggage, and mail, and may, when used together with diesel locomotives, contain an engine-generator set to provide head-end power (HEP). They can also be used with a power car or a railcar.

European railways have used control cars since the 1920s; they first appeared in the United States in the 1960s.

Control cars communicate with the locomotive via cables that are jumped between cars. North America and Ireland use a standard AAR 27-wire multiple unit cable, while other countries use cables with up to 61 wires. A more recent method is to control the train through a Time-Division Multiplexed (TDM) connection, which usually works with two protected wires.

North America

In North America, ''cab cars'' are used primarily for commuter rail and, less frequently, for longer distance trains. There are both single and bilevel models; styling ranges from blunt ends to newer, more aerodynamic, streamlined cabs. They may be very similar to regular coaches, to the point of including a gangway between cars so that they could be used in the middle of a passenger train like a regular coach if necessary.

The Chicago and North Western Railway had 42 control cabs built by Pullman-Standard in 1960, which eliminated the need for its trains or locomotives to be turned around. It was an outgrowth of multiple-unit operation that was already common on diesel locomotives of the time. The Canadian transit agency Exo uses control cars on all its trains, except its electric multiple units, which run as double-ended semi-permanently coupled three-car rakes. Amtrak also has a number of ex-Budd Metroliner cab cars, which are used primarily for push pull services on the Keystone Service and New Haven–Springfield Shuttle. The Long Island Rail Road uses cab cars on its C3 double deck coaches.

During the mid-1990s, as push-pull operations became more common in the United States, cab-cars came under criticism''Criticism of 'push' trains is on the wrong track, LA Times''
/ref> for providing less protection to engine crews during level crossing accidents. This has been addressed by providing additional reinforcing in cab cars. This criticism became stronger after the 2005 Glendale train crash, in which a Metrolink collided with a Jeep Grand Cherokee at a level crossing in California. The train was traveling with its cab car in the front, and the train jackknifed. Eleven people were killed in the accident, and about 180 were injured. Ten years later, in early 2015, another collision occurred in Oxnard, California, involving one of Metrolink's improved " Rotem" cab cars at the front of the train hitting a truck at a crossing. The truck driver left his vehicle before the impact, but the collision resulted in multiple car derailments and further cars jackknifing causing widespread injury.

Converted locomotives

From the 1970s until 1999, the Long Island Rail Road used a number of older locomotives converted to "power packs". The original prime movers were replaced with engines/generators solely for supplying HEP with the engineer's control stand left intact. Locomotives converted included Alco FA-1s and FA-2s, EMD F7s, and one F9. One FA was further converted into a power car for the C1 bi-level cars in 1991. The railroad has since switched to classic cab cars with a DE30AC/DM30AC locomotive on some trains. Longer trains require two engines, one on each end.

Until the 1980s, Ontario's GO Transit had a similar Auxiliary Power Unit (APU) program for EMD FP7s. They were frequently used with GP40-2Ws and GP40M-2s, which lacked HEP to power trains. They also found use with HEP-equipped GP40TCs and F40PHs, and were sometimes leased to other railroads. They were eventually retired in 1995 upon the arrival of the EMD F59PHs and subsequently scrapped, except for one F7A and one F7B, which were sold to Tri-Rail and the Ontario Northland Railway, respectively.

MARC had a former F7 unit, #7100, also converted into an APCU, or All-Purpose Control Unit, which occasionally substituted for a cab car. It was rebuilt with a HEP generator, newer cab controls, and fitted with a Nathan Airchime K5LA. It was used up until the late 2000s, and was donated to the B&O Railroad Museum in 2010.

Amtrak developed their Non-powered Control Unit (NPCU) by removing the prime mover, main alternator, and traction motors from surplus EMD F40PH locomotives. The control stand was left in place, as were equipment allowing horn, bell, and headlight operation. A floor and roll-up side-doors were then installed to allow for baggage service, leading to the nickname "cab-baggage cars" or "cabbages".

Six NPCUs rebuilt for '' Cascades'' service in the Pacific Northwest do not have the roll-up side doors, because the Talgo sets on which they operate have a baggage car as part of the trainset, though #90230 and #90250 were recently fitted with these doors.

Four NPCUs are used on the '' Downeaster''. These units have Downeaster logos applied to the front and the sides of the units.

Three NPCUs are designated for use on Amtrak California services. They are painted in a paint scheme similar to the old with blue-and-teal striped livery used by Caltrain between 1985 and 1997.

In 2011, Amtrak F40PH 406 was converted to an NPCU to enable push-pull operation of Amtrak's 40th-anniversary exhibit train; in addition a HEP generator was installed to supply auxiliary electricity. Unlike other NPCUs, the 406 retains its original number (instead of being renumbered to 90406) and resembles an operational F40PH externally.

In 2017, NCDOT started a Cab Control Unit (CCU) program using ex-GO F59PHs.

File:A westbound train departs OSB.jpg, A typical built Mafersa cab car with a P40DC at Old Saybrook
File:Pacific Surfliner crossing trestle at Arroyo Hondo, May 2018.jpg, Pacific Surfliner cab car in 2018
File:NJ Transit Comet V 6044.jpg, NJ Transit Comet V at Dunellen
File:Former Metroliner cab coach at Lancaster.jpg, Amtrak 9645 at Lancaster station in August 2017
File:Hyundai-Rotem Cars Presentation at LAUPT.jpg, Hyundai Rotem cab car with full upper cab.
File:MetroRail 600.jpg, LIRR 600, an FA-2 converted into a "power pack"

Europe

There are many examples of this type of vehicle in operation in Europe.

Austria

File:Montafonerbahn1.jpg, Austrian NPZ EMU Steuerwagen of the Montafon Railway in Schruns
File:Austria_cityshuttle_02.jpg, The Steuerwagen of the Austrian CityShuttle in Lower Austria
File:Railjet-Oesterreich.JPG, ÖBB Railjet Steuerwagen
File:CAT in Mannswörth.JPG, CAT Steuerwagen in Mannswörth

Belgium

NMBS/SNCB make extensive use of push-pull operation. Trains are powered by class 21 class 27 or class 18 electric locomotives and are operated in one direction from a driving carriage.

Czech Republic

In the Czech Republic, these control cabs were hardly used in the past. The main reason was concerns about the greater tendency of trainsets that do not have a traction unit at the head of the train to derail. Earlier legislation considered such a train to be sunk and for this reason the speed of such a train was limited to .

File:CD Class 912 at Kladno station CZ 328.jpg, The prototype of the Class 912 control cab in Kladno
File:07.07.19 Česká Třebová 814050 (48249805047).jpg, Class 914 in Česká Třebová railway station
File:80-29 002 CD Ostrava-Kuncice.jpg, This control cab in an old but different livery
File:80-29 003 Bftn CD Ostrava-Kuncice.jpg, Class 943 control cab in Ostrava-Kunčice
File:Ostrava střed, motorák.jpg, The picture, showing that this can be also used with a railcar.
File:Brno, Královo Pole, železniční stanice, vůz 80-30 002 (02).jpg, Class 961 control cab in Brno-Královo Pole

Finland

The VR fleet includes 12 cab cars (Finnish: ''ohjausvaunu''), classified as Edo.

France

The Corail fleet includes 28 ''voitures-pilote'', classified as B⁶Dux.

Denmark

The Danish ABs were acquired in 2002. The control car is manufactured by Bombardier. They are to be upgraded for ERTMS, starting 2019.

Germany

The first German attempts to use control cars (German: ''Steuerwagen'') and remote control-equipped steam locomotives were before World War II by the Deutsche Reichsbahn (DRB). The driver's control instructions were transmitted from the control car to the locomotive by a Chadburn-type machine telegraph (similar to engine order telegraphs on ships). The order had to be immediately acknowledged and implemented by the automatic firebox controllers. This indirect control was judged as impractical and unsafe, because, although the driver controlled the brake directly, the danger existed that in an emergency the locomotive would continue supplying "push" power for some time and possibly derail the train.

Attempts to use electric locomotives (beginning with a converted E 04 class model) were more promising, as the engine driver could control the locomotive directly. World War II interrupted the test program, despite good successes. Only after the war would control car operation be slowly accepted, when locomotives and suitably equipped cars became available.

The length of train consists in push-pull operations was originally limited to 10 cars for reasons of guidance dynamics. A speed limit of was also imposed, rising to in 1980. This was not an operational hindrance, as push-pull trains were generally initially used in six-car commuter trains.

Only since the mid-1990s have long-distance trains, which can have up to 14 cars and travel at speeds of , been operated with control cars. A special circumstance is the ICE 2, which may operate with the control car in the lead at up to on the recently built high-speed lines.

File:ICE2 007 Köln Bonn Airport Steuerwagen.jpg, ICE2 Steuerwagen at Cologne Bonn Airport
File:Dtrail1.jpg, Different livery on a double-decker German Steuerwagen
File:National Express Wittenberger Steuerwagen.JPG, Wittenberger Steuerwagen operated by National Express Germany
File:2000-12-05 IC Grosskugel.jpg, Modern German version in an older livery
File:Steuerwagen-Eisenbahnfotograph-7.jpg, Frontal view of the German model
File:Intercity Fornsbach.JPG, A German intercity train clearly showing the locomotive driving from the rear

Hungary

Control cars in Hungary are present since the 1960s. The first type of control cars used by MÁV, that is still used on low traffic branch lines was the BDt (then called BDat) series, with the BDt 100 series being capable of travelling with diesel (and formerly with steam) engines (most notably the M41 series), and the BDt 300 series being capable of travelling with electric V43 series engines. These carriages were built by the MÁV Dunakeszi Main Workshop between 1962 and 1972.

Most of the BDt 100 series, with lack of function after the Bzmot series overtook the shrinking number of unelectrified branch lines, were converted to BDt 400 series by the Dunakeszi Main Workshop, now led by Bombardier, in 2005 (after a prototype series of 7 built in 1999). They are only compatible with the V43 2xxx series, as only they have digital remote control.

With the purchase of the former East German carriage series from the DB, called "Halberstadters", 27 control cars serialed Bybdtee arrived in Hungary. Although a V43 3xxx series was introduced that has special remote control compatible to these control cars, because of the Halberstadters' rare use as branch line carriages, they are rarely used as effective control cars, and are more frequently seen as a regular carriage because of their bicycle storage space.

There are more carriages that are technically separate control cars, like the Bdx series that were part of the (now deleted from rolling stock) MDmot DMU series, or the Bmxt series that is part of the BDVmot and BVhmot EMU series, but they are considered and treated as a part of their DMU and EMU unit respectively.

File:BDt 300-as vezerlokocsi.jpg, Control car MÁV BDt 322, still the series of control cars with the largest active number in Hungary, now mainly used on electrified rural lines
File:MAV BDt-405.jpg, Prototype control car MÁV BDt 405 in its original, grey-yellow-blue livery (now repainted to the fleet color visible on the carriage behind)
File:BDt 406-os vezérlőkocsi.jpg, Control car MÁV BDt 406, the most recent control car used on lines surrounding Budapest
File:MÁV vezérlőkocsi.jpg, MÁV Bybdtee series, used rarely as an actual control car

Ireland

Iarnród Éireann operates two classes of push-pull trainsets, each with its own Control Car:
* De Dietrich (Enterprise service) with driving cab containing EMD control stand, luggage compartment and passenger seating. On this set, train heating was supplied from the locomotive Head End Power System, but this led to reliability issues on the 201 Class locomotives, so Mark 3 Generator vans have replaced one of the De Dietrich standard class coaches in the formation since September 2012.
** Numbered 9001–9004
* CAF (Mark 4) with driving cab containing replica locomotive control stand, luggage compartment and twin engine / generator sets for train heating. No passenger seating is provided.
** Numbered 4001–4008
All Mark 4 Control Cars have full-sized driving cabs with EMD locomotive type power and brake controls. Locomotive control is by means of an AAR system, modified by Iarnród Éireann (IÉ) to include control of train doors and operate with 201 Class locomotives.

Iarnród Éireann formerly operated Mark 3 Control Cars from 1989 until 2009:
* Mark 3s with driving cab containing replica locomotive control stand, luggage compartment, underslung Cummins engine / generator set for train heating and passenger seating.
** Numbered 6101–6105, converted from Mark 3 InterCity cars for suburban push-pull services. These were withdrawn in September 2009 following the introduction of 22000 Class InterCity Railcars. These units have since been scrapped apart from 6105 which has been preserved by the West Clare Railway.

Italy

In Italy, the first push-pull trains began to run after World War II.

At the time there were no systems to actually remote command the rear locomotive, so an engineer had to take place in it and command traction, following instructions (via an apposite intercom) given by the other driver, who remained in the front car, commanding brakes and sighting signals.
This lasted until the adoption of the 78-wire cable in the 1970s, which enabled full remote commanding from control cars.

Today push-pull trains are very common, and different kinds of control cars are employed:
* UIC Z1 control cars.
* MDVC type control cars, with aerodynamic or communicating cabin.
* Piano ribassato type control cars, with flat, refurbished E464-like or communicating cabin.
* Doppio Piano two floors control cars.
* UIC-X type control cars.
* Vivalto type control car.

These types allow full remote control of any Italian locomotive supplied with standard 78-wire cable, except for UIC Z1, which are used on IC services and are only able to command class E.402 locomotives, and MDVC Diesel-specific version, usable only with class D.445 Diesel locomotives.

The same driving commands are used for both rheostatic and electronic locomotives, but their meanings change.

''Vivalto'' type control cars, at this time, can only remote command Class E.464 and Class E.632 locomotives, because of software issues, though are able to command other locomotive types.
Vivalto cars can also use TCN remote control cable.

Driving cars can be recognized because of the "np" in their identification number and usually also have a dedicated compartment for bicycle and luggage transportation.

There also are specific EMU/ DMU non-motorized units control cars, which (in Trenitalia) are classified as Le / Ln XXX with no significant difference between them and motorized units except the lack of traction motors.

File:Piano ribassato pilot.jpg, ''Piano Ribassato'' driving carriage with E.464-like cabin
File:DUEPIANI-Udine-06-97.jpg, ''Doppio piano'' driving carriage at Udine station in 1997
File:UIC-Z1 semiPilota.jpg, Control car UIC-Z1
File:Stazione di marotta-mondolfo con vivalto.jpg, Double-decker driving carriage ''Vivalto''
File:Carrozza semipilota MDVC Trenord.jpg, Trenord cab car MDVC

The Netherlands

The use of cab cars (Dutch: stuurstandrijtuig) in The Netherlands by NS is becoming rare due to the conversion of the sets to EMUs and the discontinued use of control cars on ''intercity direct'' services.

The use of a "virtual EMU" concept for some short-distance trains in the north of the country is where train sets are formed of a driving carriage, two or three intermediate carriages and a class 1700 electric locomotive. These train sets are diagrammed as if they were all EMUs resulting in formations with two locomotives, often at intermediate positions in the train. Most of the train sets have been converted into double-decker EMUs called DDZ.

Poland

In Poland, the term used is "wagon sterowniczy", which literally means "control carriage".

Koleje Mazowieckie use driving trailers on their regional services. The first batch of double-decker driving trailers and cars, the Twindexx Bombardier Double-deck Coaches, was delivered in 2008. The second batch, PESA-made Sundecks, was delivered at the end of 2015.

Slovakia

In 2011, the state-owned Slovakian railway operator ZSSK introduced a JNR-based passenger train operator; a push-pull operation train series manufactured by Škoda Transportation, including Class 381 electric 109E locomotives and even Class 263 alternating-current locomotives, provides the vehicles utilised by the company. The Class 951 system train coaches remain introduced at Bratislava hlavná stanica, which these generally operate in conjunction with commuter rail and regional rail.

Sweden

There has only been one type of control car in service in Sweden. Only three examples of the AFM7 were made and they are currently in service with SJ in the Mälaren Valley. The Swedish word for control car is ''manövervagn'' which literally means "manoeuvre car".

Switzerland

Swiss driving trailers operate in many different configurations. There are several models currently in service on S-Bahn networks as well as regional, InterRegio, and InterCity services. These are operated by the federal railway system ( SBB) as well as various private railroads throughout the country (including narrow gauge lines) and into France, Germany, and Italy.

Driving trailers are classified after the UIC-lettering system, adding a "t,” giving ''Bt'' (second class), ''BDt'' (second class + baggage), ''ABt'' (first + second class), or ''Dt'' (baggage).

For Intercity trains there are the Bt IC that work together with EW IV and the double-deck version for the IC 2000 trainsets, working with Re 460.

The Zürich S-Bahn trainsets with Re 450 work in fix consists of Re 450 - B - AB - Bt but intermediate cars and driving trailers are numbered as coaching stock.

"NPZ" Regional and S-Bahn trains with RBDe 560 usually have a matching Bt driving trailer. Replacement by an older BDt EW I/II is technically possible. Older driving trailers, mostly BDt EW I/II and a few remaining Dt of SBB can be used with Re 420 and RBe 540 and some motive power of private railways. In theory also Re 430 and Re 620 can be controlled but these classes only work freight trains today.

The BLS operates four groups of driving trailers:
* ABt NPZ to go with RBDe 565 and RBDe 566 II (ex RM)
* Bt EW I 950-953, BDt 940-941, car-shuttle BDt 942-945, 946-949 and 939 can work with Re 425, Ae 4/4 and Re 465
* Bt EW III, BDt EW II (both ex SBB), Bt EW I 901-902 (ex Thurbo/MThB) and leased Dt from SBB can work with Re 420.5 ex SBB and BLS Re 465.
* Bt EW I 950–953, BDt 940–941, car-shuttle BDt 942–945, 946-949 and 939 can work with Re 425, Ae 4/4 and Re 465

Südostbahn had a fleet of ABt for their BDe 4/4 but they will soon be fully replaced by FLIRTs. NPZ ABt exist for the two types of RBDe 566 SOB owns (566 071-076 ex BT and 566 077-080 ex SOB of the SBB-type). Nine BDt are used for the Voralpen-Express with Re 456, Re 446 or SBB-CFF-FFS Re 420.

The narrow gauge Zentralbahn ABt can control HGe 101 (ex SBB), De 110, BDeh 140 (ex LSE) and the new "SPATZ" ABe 130.

The Rhaetian Railway (RhB) has, besides the ABDt that work with Be 4/4 511-516, a group of driving trailers that can be used with their Ge 4/4 I, II and III locomotives. Three of them are specially fitted for Vereina car shuttle trains.

The Matterhorn-Gotthard-Bahn (MGB) has numerous driving trailers for almost all types of motive power. They work regional trains and car shuttle trains through the Furka Base Tunnel.

File:SBB IC2000 Bt in Zürich.jpg, Double-decker Swiss IC 2000 Steuerwagen
File:SBB Re 450 Bt in Zürich.jpg, S-Bahn Zürich double decker
File:CH SBB NPZ Steuerwagen.JPG, Swiss NPZ Steuerwagen in Biel
File:BLS Steuerwagen.jpg, The BLS Bt EW III (former Swiss Express)

United Kingdom

In the United Kingdom, ''driving trailers'' may have one or two driving cabs. They have been used for many decades, with the Great Western Railway often using autocoaches on branch line services. These allowed a train driver to remotely control the regulator and reverser of a suitably equipped locomotive. The fireman remained on the locomotive to operate the boiler and locomotive whistle. Locomotives were commonly sandwiched between a pair of autocoaches, allowing a maximum of four to be used.

Driving Trailers

A Driving Brake Standard Open or DBSO is a specially converted Mark 2 passenger car. Initially operated by ScotRail from 1979, they were operated on InterCity and Anglia Railways services on the Great Eastern Main Line from the late-1980s until 2006. Some have been refurbished for use on Network Rail test trains. Others were used by Direct Rail Services on Cumbrian Coast line locomotive hauled passenger trains under contract to Northern Rail until late 2018 when they were replaced by regular Diesel multiple units.

Transpennine Express's Mark 5a sets include a purpose built Driving Trailer.

File:DBSO 9710 at Norwich.JPG, DBSO 9710 in InterCity livery at Norwich
File:Rail-dbso-amoswolfe.jpg, DBSO in Anglia Railways livery
File:TransPennine Exress Mark 5a first test at Crewe.jpg, Mark 5a Driving trailer

Driving Van Trailer

A Driving Van Trailer or DVT is a more modern type of control car, purpose-built to include space for baggage and a guard's office. The DVT was developed in the late-1980s from the DBSO and designed to be used with Mark 3s on West Coast Main Line services and Mark 4s on the East Coast Main Line. As of February 2021, Mark 3 DVTs are in service with Chiltern Railways and Network Rail, with Mark 4 DVTs in service with London North Eastern Railway with some to be operated by Transport for Wales Rail from 2021. Former operators of the Mark 3 DVTs are Arriva Trains Wales, Greater Anglia, KeolisAmey Wales, Virgin Trains West Coast and Wrexham & Shropshire.

File:A_First_Refurbished_Train_Launch.JPG, Wrexham & Shropshire Mark 3 DVT at Marylebone station
File:Mk4DVT-82201-03.jpg, GNER Mark 4 DVT at Leeds station

Oceania

Australia

NSW

All of the driving trailers are generally on much of the earlier rolling stock. Examples of these driving trailers were on some old (now most likely scrapped) red rattler cars along with C and K sets (4 trailers). The driving trailers from the K set were later converted to ordinary trailers. These can be noted by the positioning of the pantograph. On a single set the pantographs are placed on the second and third cars, and on an eight car train (2 sets combined) they're placed on the second, third, sixth and seventh cars. Some third Generation of Sydney Trains, Tangaras or T sets, have driving trailers but are equipped to supply electricity to the train though the use of a pantograph.

Waratahs (A sets) have two driving trailers (one at each end) with power trailers in between the driving and non-driving trailers.

South Australia

2100 class railcar are driving trailers, being placed in a 2-car consist with a 2000 class power unit, sometimes with a second trailer to make a 3-car consist-the power car would be placed in between the two trailers. As of 2018, only three of these trailers exist, the rest were scrapped. Two are preserved and one that was donated to South Australian Metropolitan Fire Service (cut-in half). Three 2000 class power units out of the twelve have had the same fate.

New Zealand

Experiments with light railcars were aimed at cutting costs on lightly-used branch lines. Autotrains were built in 1906 and 1907 and by 1925 NZR had 8 88-seat and 5 72-seat motor trains. In 1908 there was a motor train Auckland suburban service to Ōtāhuhu and between Morrinsville and Putāruru in 1913.

In Auckland, Transdev Auckland operated 21 DC class locomotives and four DFT class locomotives (owned by KiwiRail) in push-pull mode with 24 sets of 3-5 SA cars and an SD driving car with driving cab and remote controls (ex British Rail Mark 2 carriages rebuilt for suburban service), owned by Auckland Transport."Ticket to Ride" e.nz magazine, July/August 2007 Volume 8/4, pages 24-28 The carriages were replaced with EMUs in July 2015.

Asia

Sri Lanka

Control cars are available on most Diesel multiple units operated by Sri Lanka Railways.

Israel

Control cars are available on most Diesel multiple units operated by Israel Railways.

India

Control cabs are generally found on DEMU's, EMU's and MEMU's in India.

See also

* Cab (locomotive)

References

{{Reflist

Passenger railroad cars