Control car

A control car, cab car, control trailer, or driving trailer 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. 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. 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 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. Amtrak also has a number of ex-Budd Metroliner cab cars, which are used primarily for push pull services on the Keystone Service and Amtrak Hartford Line. 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 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 eight and ten Alco FA-1s and FA-2s, four 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. Trains going into Penn Station require two DM30AC locomotives on each end in order to make use of their 3rd rail pickups.
Until the 1980s, Ontario's GO Transit had a similar Auxiliary Power Unit program for twelve 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 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 VI sets on which they operated had a baggage car as part of the trainset, though #90230, #90250, and #90251 were later fitted with these doors. #90250 was originally painted in the Cascades scheme, but was later repainted into Phase V livery. These units have since operated with standard Amtrak cars since the Talgo VI's retirement in 2020.
Four NPCUs, #90213, #90214, #90220 and #90224 are exclusively 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 resembles an operational F40PH externally and initially retained its original number. In 2024, it was renumbered to 90406 to avoid duplicate numbering with the ALC-42s.
In 2017, NCDOT started a Cab Control Unit program using ex-GO F59PHs. Five CCUs have been ordered, numbered 101-105. These are used on the Piedmont.
In 2023, Amtrak began testing a former HHP-8 locomotive as a cab car with the aim of supplementing or replacing the existing ex-Metroliner cab cars until the Airo fleet arrives. As of July 2024, eight total conversions are planned.
In 2024, Amtrak started converting their GE P42DC locomotives into Non-Powered Control Units, starting with Amtrak P42DC #184, which is now Amtrak P42C #9700.

Europe

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

Austria

Belarus

In Belarus, as part of push-pull trains, control and intermediate cars from DR1 DMUs manufactured by the Riga Machine-Building Plant are used. After the decommissioning of power cars, some of them were converted into control cars by replacing the engine room with a passenger compartment, and at the other end of a train, one unit of 2M62 or 2M62U diesel locomotives started to use instead of another DR1 power car. Later, the control cars of DRB1 trains began to be produced by RVR initially for push-pull trains on a par with DMUs. RVR also produced DRB2 control cars for such trainsets, which a similar to control cars of the ER9 EMUs.

Russian Federation

In Russia, as part of the first Push-Pull railway train DP2D Driving Trailers used to operate a TEP70 diesel locomotive from other side of the train. The trailers are ultimated with EP2DM head cars, making the replacement simple. Currently, these trailers are conpleting the certification testings along with the DMUs.

Belgium

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.

Finland

The VR fleet includes 42 cab cars, 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 and remote control-equipped steam locomotives were before World War II by the Deutsche Reichsbahn. The driver's control instructions were transmitted from the control car to the locomotive by a Chadburn-type machine telegraph. 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 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.