DB Class 101

DB Class 101
Company type	Electric locomotive series
Industry	Rail transport
Predecessor	DB Class 103
Founded	1996
Headquarters	Germany
Products	Three-phase electric locomotives
Parent	Deutsche Bahn

The DB Class 101 represents a series of three-phase electric locomotives constructed by Adtranz and operated by DB Fernverkehr within Germany. Produced between 1996 and 1999, a total of 145 units were delivered to succeed the aging DB Class 103 as Deutsche Bahn's premier locomotive for hauling Intercity trains. By 2024, this series is undergoing phased retirement and dismantling.

The American Bombardier ALP-46 traces its design lineage back to the DB Class 101, sharing common elements with the Bombardier Traxx locomotive family.

Background

During the early 1990s, Deutsche Bahn confronted rising maintenance expenses and reliability challenges with its fleet of high-speed electric locomotives. The three-decade-old DB Class 103, operated at speeds up to annually on heavier and faster services, experienced significant wear in components such as control systems, traction motors, and bogies. The cost-reduction initiative known as Program DB 90 exacerbated these issues through a strategy dubbed "Drive to Deterioration."

Likewise, the three-phase DB Class 120 locomotives and the former East German Class 112 units were becoming outdated and costly to maintain. Deutsche Bahn aimed to introduce a contemporary replacement that incorporated the advanced technologies present in Class 120 models.

In early 1991, Deutsche Bahn launched the Class 121 project to develop versatile high-performance locomotives capable of exceeding output thresholds and reaching speeds of . However, initial concepts proved financially unviable, and operational specialization diminished the demand for all-purpose engines.

A subsequent Europe-wide tender issued in December 1991 drew over thirty submissions ranging from below to above power levels, including single-cab designs similar to Italy’s FS Class E464. These single-cab proposals were ultimately dismissed due to their limited operational flexibility and marginal cost advantages.

Non-German manufacturers such as Škoda Works, Ansaldo, and Alstom were excluded early because their designs did not meet Deutsche Bahn's stringent standards. German companies—Siemens Mobility, AEG, and Adtranz—stood out by offering modular solutions adaptable to varied requirements.

Siemens, collaborating with Krauss-Maffei, developed a prototype EuroSprinter (class 127), while AEG rapidly advanced the 12X concept (later known as Class 128001). ABB Henschel contributed conceptual designs like Eco2000, utilizing two enhanced Class 120 prototypes to trial cutting-edge technologies such as GTO-thyristor power converters, flexi-float bogies adapted from ICE trains, disc brakes, and environmentally friendly cooling fluids.

In December 1994, Deutsche Bahn signed a letter of intent with ABB Henschel, culminating in an order for 145 locomotives placed in July 1995. The first unit was revealed in July 1996, adorned in orient red livery. By this time, ABB Henschel had merged with AEG to form Adtranz. The locomotive bodies were fabricated at facilities in Hennigsdorf and Kassel; those produced in Hennigsdorf were transported by truck to Kassel for final assembly alongside bogies manufactured in Wrocław, Poland. The inaugural locomotive commenced service on 19 February 1997.

Body Design

Class 101 locomotives are characterized by prominent sloping fronts and rears engineered for aerodynamic optimization and cost efficiency. Designers deliberately avoided multiple curved surfaces or additional tapering that would increase the gap between locomotive and coaches, which could generate air turbulence and diminish aerodynamic gains.

The underframe support structures consist of large welded C-sections combined with steel plates of varying strengths manufactured at plants in Hennigsdorf and Wrocław. Front-side buffers are engineered to withstand forces up to , while the section beneath the upper windows is designed to endure loads reaching .

The driver’s cab front employs thick steel plates measuring . Front window panes are interchangeable on both sides and adhered without frames. The cab roof is integrated directly with the body shell rather than the overall roof structure. Four light alloy doors provide direct access into the cabs.

Side windows pivot open to prevent corrosion-prone window wells, contrasting with recessed windows found on class 145 and 152. All windows and doors feature full pressurization using specialized seals.

Body side panels are constructed from 3 mm thick material supported by columnar sections housing cable conduits. These panels extend from behind the cabs up to the beginning of the sloped roof segment, terminating in a hollow section that supports removable roof components. Two welded steel plate belts connect these panels.

The aluminum roof comprises three detachable sections—including fan grills and slopes—allowing unobstructed access for maintenance tasks. Roof segments rest upon side panels, connecting belts, and fixed cab roofs sealed with floating seals. Except for pantographs, signal horns, and radio antennas, the roof remains flat to maintain aerodynamic efficiency.

Equipment mounted on the roof is positioned just beneath the cab roof edge to reduce wind resistance; even lowered pantographs remain minimally visible. Pantographs are hinged inward-facing—a departure from other German locomotives—to preserve aerodynamic profiles while aligning above bogie centers without encroaching into raised cab roofs.

A distinctive attribute of class 101 is its bogie side frame covers, which extend along the frame down to wheel bearings, enhancing aerodynamic smoothness throughout operation.

Bogies/trucks

The bogies for the class 101 were developed by Adtranz and Henschel with future advancements in mind, capable of supporting maximum speeds inspired by ICE technology, although the class 101 locomotives themselves operate at a lower top speed. These bogies are adaptable to various track gauges and offer the option of radially adjustable axles, a feature that DB ultimately chose not to implement.

While they share ICE heritage, the class 101 bogies exhibit notable differences. They are designed to be more compact, balancing high-speed stability with efficient curve negotiation by reducing the wheelbase from the ICE's to , and utilizing large-diameter wheels. This compactness minimizes relative motion between the vehicle body and bogies, allowing motor cables to be routed outside ventilation ducts, which simplifies assembly and extends service life.

From a structural perspective, the bogies consist of two main lateral beams combined with two cross beams, deliberately omitting a central welded cross beam. Forces generated during traction and braking are transmitted via two rods connected through pivot pins that are slightly inclined and mounted with springs to ensure balanced movement.

Wheels are mounted on hollow axles made of chrome-molybdenum steel alloy—the standard German diameter is , with a minimum permissible diameter after wear of . These axles also house the wheel set bearings and connect through hollow shafts into the gearbox casing, integrating the traction motor within an "integrated common drive train" (IGA). This design aims to reduce maintenance demands and improve oil seal integrity, contributing positively to environmental protection.

Power delivery to the axle is achieved through a universal joint incorporating rubber elements. Each bogie’s pair of wheels is fastened using six large bolts that are visible from the platform level.

Brake system and traction motors

The hollow shafts accommodate two ventilated disc brakes per bogie, made possible by the absence of a central cross beam and pivot pin. These disc brakes feature internal ventilation and can be serviced or replaced from underneath without removing the axle. Under normal braking conditions, regenerative braking is primarily utilized, with traction motors functioning as generators. A specialized brake control computer coordinates the interaction between regenerative and disc brakes.

Each wheel is equipped with an individual brake cylinder, supplemented by an additional cylinder per wheel set for spring brakes that serve as hand or parking brakes, capable of securing the locomotive on gradients up to 4%.

The traction motors are designed without housings and operate at speeds up to , running at 3,810 rpm; a gear ratio of 3.95 limits their maximum rotational speed to below 4,000 rpm. They deliver a peak power output of with torque reaching . Cooling is managed by motor blowers controlled via integrated sensors and powered by an auxiliary inverter, which circulate air through a closed duct system to maintain cleanliness in the engine compartment. Each blower moves up to of air, with entering the engine room. The weight of each traction motor is , while each bogie weighs approximately .

The traction drive is mounted on a central auxiliary beam within the bogie frame, connected via two pendulum mounts to the outer sides—a configuration enabled by the pivot-pin-free design supported by eight flexicoil springs. Movement range is controlled by hydraulic buffers combined with rubber elements. This flexicoil suspension setup reduces component wear and lowers maintenance requirements by eliminating several traditional parts.

Compressed air system

The class 101's compressed air arrangement is similar to those found in other locomotives. Air enters the engine compartment through a filter and is compressed by a screw-type compressor up to a maximum pressure of . A pressure regulator controls the compressor, which engages at and ceases operation at . The compressed air then passes through an air conditioning unit before being stored in two main reservoirs. Safety valves are installed to prevent pressure from exceeding and bar. Additionally, the compressor halts if the oil temperature rises beyond a set limit.

In cases where air pressure is inadequate during start-up, a battery-driven auxiliary compressor can provide air to the pantographs and main switch at up to , despite an automatic shut-off valve activating when the locomotive powers down.

This compressed air system serves multiple functions, including:

brake operation
sand distribution
flange lubrication
windshield cleaning
train horn activation

Sand distribution system

To enhance traction between wheels and rails during braking and acceleration, sand is stored in eight containers located under the chassis—one container per wheel. When triggered by the driver, compressed air disperses sand through outlets positioned ahead of the front wheels relative to travel direction. Below , the system heats the sand and periodically stirs it inside the containers.

Flange oilers

A biodegradable lubricant is automatically sprayed using compressed air into the gap between wheel flange and rail surface on the leading wheels. The application rate adjusts based on speed to minimize wear on wheel flanges.

Train whistles

Two whistles producing tones at 370 Hz and 660 Hz are mounted on each driver’s cab roof. Activation occurs via a pressure valve near the driver’s footwell or pneumatic pushbuttons located around the cab interior.

Pantographs

The locomotive features two DSA 350 SEK pantographs—half-pantographs rather than diamond-shaped full types—originally developed by Dornier and manufactured in Berlin-Hennigsdorf. Currently, Stemman-Technik GmbH in Schüttdorf produces and supplies these units, each weighing .

Affixed to the roof at three mounting points, pantograph 1 connects directly to the main control switch within the engine room, while pantograph 2 links via a cable splice along the engine room’s side wall. The graphite contact strips incorporate a monitoring mechanism: if internal air pressure within an overpressurized channel drops due to damage, automatic retraction is triggered to protect the overhead contact wire.

Pantographs are raised using compressed air at 5 bar (), requiring approximately 5 seconds to lift and 4 seconds to lower. Contact shoe pressure against the catenary wire can be adjusted between . Operators manage pantograph functions through push buttons labeled Up, Down, and Down + Sanding (for emergencies). The system can automatically select the rear pantograph aligned with travel direction or coordinate front and rear pantographs across multiple locomotives during double heading. Alternatively, drivers may manually raise one or both pantographs using a switch located on the battery control panel in cab 1—particularly useful during shunting operations to prevent automatic switching when moving between cabs. When changing pantograph position, the lowered unit is raised first before lowering the active one.

Compressed air necessary for pantograph movement and monitoring is delivered via two teflon-coated hoses mounted on the roof, engineered to withstand voltages up to 15,000 volts from the overhead line.

Transformer

Differing from other locomotive categories, the class 101 transformer is installed beneath the engine room floor, mounted directly on the frame. This arrangement allows for a streamlined engine room design and necessitates a unique structural approach. Constructed from lightweight steel, the tank is reinforced at critical points to endure minor derailments or collisions.

The transformer comprises seven distinct electric coils:

Four coils deliver power converters operating at 1,514 volts with a capacity of 1.6 MVA
Two coils provide power to trainlines—supporting carriage heating, cooling, and electrical supply—and disturbance filters at 1,000 volts and 600 kVA
One coil energizes three auxiliary inverters rated at 315 volts and 180 kVA
One coil feeds the battery charger, cab climate control systems, and pressure protection equipment at 203 volts and 20 kVA

Cooling is managed by circulating a polyol-ester fluid via two independent canned motor pumps designed to significantly reduce leakage risks. Each pump can be isolated and replaced individually. Should one pump fail, cooling persists with diminished efficiency, permitting transformer operation at approximately 65% of full power.

Software and other control systems

Class 101 locomotives are equipped with the automatic drive and brake control system (AFB, Automatische Fahr- und Bremssteuerung), which aids drivers by optimizing acceleration and braking across varying conditions while maintaining steady speeds.

They also feature Superschlupfregelung ("super slip control"), a system that regulates wheel rotation to prevent damage to rail surfaces and enhance traction between wheels and tracks. Although initially fitted with radar technology for precise speed measurement, this proved unnecessary for effective functioning.

The onboard control system employs ABB's MICAS S, a computerized 16-bit platform utilizing a bus architecture for vehicle management, monitoring, and diagnostics. This setup considerably reduces wiring complexity compared to predecessors such as the class 120, with most cabling routed through the side walls of the locomotive body.

At its core lies the central control unit (ZSG), implemented with redundancy through duplication. It processes inputs from various onboard systems and issues operational commands affecting train functions. The ZSG contains four processors responsible for overseeing controls and safety mechanisms, including the dead man's vigilance system.

Safety systems integrated into the class 101 include PZB 90, which enforces compliance with signals and triggers emergency braking when necessary, and LZB 80, facilitating continuous communication with centralized control centers to monitor train position and speed. Units numbered 101 140 to 144 are engaged in testing the European Train Control System (ETCS), intended as a standardized train control solution across Europe.

The electronic timetable system EBuLa supports drivers by providing real-time schedule adherence information, speed guidelines, temporary speed restrictions, and alerts about line irregularities on all DB AG trains.

The diagnostic platform DAVID—developed from ICE technology—enables continuous monitoring of faults with immediate feedback to both drivers and maintenance personnel. This proactive approach minimizes downtime by allowing preparation ahead of maintenance needs rather than relying on fixed inspection points.

Deployment

Initially, class 101 locomotives were planned to be stationed at Frankfurt, a major German intercity junction, aiming to streamline scheduling and maintenance by facilitating locomotive changes at this terminus.

However, increased ICE traffic involving control cars, Deutsche Bahn's preference for push-pull operations centered in Frankfurt, alongside the substantial expense of constructing a new depot there, prompted reconsideration. Instead, spare capacity at the Hamburg-Eidelstedt ICE depot—originally designed for trains with 14 center carriages but operating with only 12—was allocated for servicing class 101 units.

Adtranz maintained a dedicated support team at Hamburg-Eidelstedt to fulfill warranty commitments; two representatives remained on site as of 2002. Despite operational complexities—including the need to recruit additional drivers skilled in intricate shunting maneuvers—locating class 101 maintenance operations in Hamburg proved more economical than building new facilities elsewhere.

Routine servicing of class 101 locomotives occurs every 100,000 kilometers at Hamburg and encompasses minor repairs along with wheel tyre reprofiling using an underfloor lathe. Major overhaul work was originally conducted at Nuremberg but was later transferred to Dessau due to capacity limitations; occasionally, manufacturer-based servicing took place in Kassel.

Withdrawal

As of September 2024, a total of 34 class 101 locomotives have been dismantled. The initial retirements took place in December 2020, involving units 101 144 and 101 112, with scrapping operations starting in September 2021 following the recovery of usable components.

The deployment of new ICE trainsets has resulted in an excess of class 101 locomotives. With Deutsche Bahn gradually retiring IC1 trains, the process of withdrawing class 101 units began in 2023. Although DB Cargo might repurpose some locomotives for alternative applications, the current market demand remains limited.

Bibliography

Baur, Karl Gerhard Im Führerstand. Baureihe 101. In: LOK MAGAZIN. Nr. 244/Jahrgang 41/2002. GeraNova Zeitschriftenverlag GmbH München, , S. 60–62.
Klee, Wolfgang. Die Hochleistungs-Universal-Loks der BR 101. In: Die Baureihen 101, 145, 152 und 182. Sonderausgabe 1/2001 EisenbahnJournal , S. 22–39.

External links