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Setting Trends: Deutsche Bahn class 120.1 electric from ACME


NGT6 1315

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Morning all!

 

In today’s loco profile, you will learn a bit more about a locomotive which at the time of its roll-out could be said to have been the pride and joy of the German railway industry. Even though it was eventually built in 60 examples only, the class 120 electric definitely contributed much to the breakthrough of three-phase AC traction.

 

The rationale behind the 120’s development was that Deutsche Bundesbahn were intending to supplement their fleet of class 103 express passenger locomotives and class 151 heavy freight locomotives, both Co’Co’ configured but designed with specific roles in mind, with a Bo’Bo’ configured universal locomotive capable of handling either role equally well.

 

To obtain this kind of universal, mixed traffic locomotive, Deutsche Bundesbahn were willing to put asynchronous AC motors and electronically controlled, semiconductor-based inverters to the test. This decision was made based on the experience gained during a test campaign involving 202 002, one of three prototype diesel-electric locomotives with asynchronous AC traction built by Henschel and BBC in 1971 and 1973. In 1974, 202 002 had been rebuilt as a testbed and permanently coupled with an adapted BDnrf740.2 driving trailer. In this configuration, 202 002 had had its prime mover and generator removed, while the driving trailer was outfitted with a transformer and pantograph, so that 202 002 essentially simulated a fully electric locomotive.

 

As this trial, which lasted into 1975, demonstrated that a hypothetical asynchronous AC electric could indeed handle almost the complete spectrum of train services offered by Deutsche Bundesbahn at the time, the railway contracted a consortium of BBC – providing the electrical components – and Krauss-Maffei, Krupp and Henschel in 1976 to develop and build a pre-production series of five such locomotives. This development was paralleled by coal mining enterprise Ruhrkohle AG obtaining six Henschel E 1200 series, centre-cab electric freight and shunting locomotives, which were similarly based on asynchronous AC propulsion. With these locomotives fully satisfying all expectations, the consortium for what would become the class 120 locomotive had a broad basis of experience to work from.

 

As the first of the five pre-production locomotives, 120 001 was handed to Deutsche Bundesbahn on 14 May, 1979, with the four remaining locomotives following till January 1980. Initially, 120 001 through 004 were approved for only 160 kph, while 120 005 was certified for the targeted maximum speed of 200 kph later. The locomotives were rebuilt with various modifications during their evaluation, among these being optimised transformers. It is also worth noting that the power units for the class 401 and 402 1st and 2nd generation ICE sets, which began entering service by the end of the 1980s, are closely related to the 120.

Of these five locomotives, 120 005 stood out by having a slightly differently designed body with a lower frontside waist line, and initially with additional rooftop fairings as well.

 

On 13 August, 1980, 120 002 set a new world speed record of 231 kph for motive power with asynchronous AC propulsion. During the official two-day presentation in 1984, 120 001 pushed the limit even further to 265 kph, pulling a 250 tonnes train. One year later, 120 001 was further upgraded to allow for a maximum speed of 280 kph.

Several other types of motive power from the Bundesbahn era picked up cues from the 120’s general visual appearance, such as the class 240 diesel-electric prototype, class 628 DMU, and the driving trailers for the „x“ Stock suburban coaches.

 

Also in 1984, Deutsche Bundesbahn ordered a total of sixty production locomotives, which became known as class 120.1 and included a number of modifications developed out of the experience gathered during the prototype evaluation phase. This order had a total value of 380 million Deutsche Mark. The production locos were lacking the back-up rheostatic brake, as the regenerative brake had been found to be quite sufficient and reliable.

 

Deliveries lasted into 1989, with the 120.1s usually being diagrammed onto InterCity and InterRegio workings by day and onto fast freight services by night. 120 137 through 160 were outfitted with a modified gear ratio, which increased tractive effort at high speeds, though at the cost of reduced tractive effort at lower speeds.

 

Following the formation of Deutsche Bahn, the 120.1s were summarily allocated to the Fernverkehr sector, whose responsibility covers long distance passenger traffic. The five pre-production locomotives, commonly referred to as class 120.0, but were mainly relegated to departmental work, usually diagrammed onto inspection and measuring services or used for stock trial and certification services. They were thus reclassified as class 752 locomotives, which designation they retained for many years.

 

In addition, 120 004 and 005 were outfitted as component and technology demonstrators for ABB Henschel, then one of the contestants and eventually the winner for that contract which brought forth the class 101 electric locomotives. These locomotives served as testbeds for inverters and bogies intended to be used on the 101. 120 004 is often referred to as the de-facto class 101 prototype as it had been most extensively rebuilt.

 

None of the 120.0s remain in service, with 120 001 having been totalled in an accident in 2004, and 120 002 having been broken up as well. 120 003 has found a place at the Nuremberg Transport Museum’s Bahnpark Augsburg complex. 120 004 is now owned by the DB Museum in Koblenz, while 120 005 is part of the Weimar Railway Museum’s collection.

 

Presently, 49 locomotives remain in DB Fernverkehr service, and continue working mainly InterCity services. Like the 101s, the 120s but can also be seen working a handful of freight services in between passenger turns. 120 158 has been withdrawn to serve as a spares donor. Eight locomotives – 120 116, 129, 107, 128, 121, 117, 136 and 139 – have been passed to DB Regio, and been outfitted with expanded passenger information equipment. These locomotives are now referred to as class 120.2, and numbered 120 201 through 208. Five of them are permanently in use on the Hamburg-Rostock RegionalExpress line, which is also known as „Hanse-Express.“ The other three locomotives were originally intended to augment DB Regio’s Westphalian sector, but after having suffered repeated malfunctions there were earmarked as reserves for the Hanse-Express service.

 

Finally, 120 153 and 160 were passed to DB Systemtechnik, and redesigned 120 501 and 502. These locomotives are commonly used for inspection and measuring services, and have most recently been repainted in a bright yellow livery to highlight their new role.

 

In 2005, DB AutoZug had obtained several 120s for their Motorail and sleeper services, which but were soon returned to DB Fernverkehr. As an interesting note, those locos detached to DB AutoZug were intended to be redesignated as class 121, but only 120 113 was ever thus numbered. In the final years of Deutsche Bundesbahn, it was planned that a future universal follow-up locomotive to the 120 should be designated class 121, but the fact of the different Deutsche Bahn sectors created in 1994 favouring motive power tailored to their specific requirements rendered moot any further attempts to obtain universal, mixed traffic locomotives as the 120 had been.

 

Technical description

 

The 120 pioneered various design innovations not seen on any previous electric locomotive to have been developed, though most of these innovations are not immediately visible.

 

The body is an all-welded, self-supporting assembly set atop the fully welded running frame and with single-piece, non-reinforced engine room sides. It consists of the pressure-strengthened cabs with integral roof sections, and the engine room proper, with the roof being split into four separate panels. As a novelty, the 120 was designed such that all inverter and equipment cabinets were set along either side of the engine room, leaving a straight, uninterrupted central corridor between the cabs. As on later electric locomotives, the transformer was designed such that it could be hung below the engine room floor, with the traction inverters being set immediately atop.

The cab layout follows the Deutsche Bundesbahn Standard Cab design first implemented on the class 111 electrics, there originally called „Integrated Cab.” This layout was also utilised on the Bxf796 driving trailers for the „x” Type suburban stock, and on the ICE 1 and 2 power units. With further modifications, this design has become the de-facto standard on the majority of German-built mainline locomotives, especially the Bombardier TRAXX and Siemens Eurosprinter, Eurorunner and Vectron series. It combines a flat control desk with a tilted triple display plane set in between the windscreen and the driver’s seating position. Power and brake controllers are within easy reach of the driver’s left and right hand respectively.

 

The bogies are fully welded as well, and were designed with a conventional pivot pin with low-set, annular rubber dampened bearing and two sets of three Flexicoil springs per side to serve as secondary suspension. The wheelsets with Monobloc wheels are attached by way of lemniscate levers and held in roller bearings, with springs and auxiliary motion dampers serving as primary suspension. Power transmission is made through a BBC quill drive with single-sided reduction gear and fully suspended, low-hung, four pole asynchronous AC traction motors.

 

Electrical equipment comprises the underfloor transformer with two traction taps and one auxiliary tap, and the two sets of traction inverters, with each pair of inverters feeding one bogie. These inverters work with an intermediate DC link at a working tension of 2,800 V, and provide an three-phase AC output of 0 to 2,200 V at 0.4 to 150 Hz. They can also work in regenerative braking mode, feeding back the usual 15,000 Hz at 16.7 Hz. Power pickup is made through a pair of SBS 80 type single arm pantographs, which are an evolved, lighter version of the proven SBS 65 pantograph widely used on the class 103 and 111 locomotives and others.

 

The auxiliary electric circuits were, as a further innovation, also configured for asynchronous AC. They are fed through three auxiliary inverters. Auxiliary inverters 1 and 2 provide variable-frequency AC and power the motor blowers for the corresponding bogie, as well as one of the two transformer coolant blowers. Auxiliary inverter 3 provides fixed-frequency AC and supplies the transformer coolant pumps, compressor and other fixed-frequency devices.

 

Braking gear on the 120 comprises the pneumatic brake, which is configured as a tread brake and based on a unified Knorr brake controller with settings G, P and R, plus direct shunting brake controller and spring-loaded parking brake units. The pneumatic brake is blended with the regenerative brake, which is prioritised over most of the locomotive’s speed range. It was also amended with a tread cleaning setting where the brake pads are applied at a pressure of 0.25 bar to enhance adhesion in poor weather conditions.

 

Safety equipment comprises an alerter, as well as a combined PZB train protection and LZB cab signalling suite. Furthermore, the 120 is outfitted for ECP brake controls and emergency brake override, or „Notbremsüberbrückung” (NBÜ) in German railway terminology.

For workload relief, the 120 also has automatic power and brake control, called „Automatische Fahr- und Bremssteuerung” (AFB) in German. This system is integrated with LZB, allowing the locomotive to operate semi-automatically on lines such equipped as AFB will pick up target speed and braking distance commands from LZB. Finally, it is worth mentioning that the 120 is outfitted for TDM double traction and push-pull controls, making it compatible with the Bpmdzf and Bimdzf type driving trailers used on InterCity formations, and, technically, all other driving trailers such equipped.

 

 

Technical specifications

 

Overall length, width and height – 19.20, 2.95 and 4.25 m (63, 9.7 and 14 ft)

Service weight – 84 tonnes (82.7 long tons)

 

Continuous power output – 5,600 kW/7,510 hp

Initial tractive effort – 340 kN for 120 101 through 136, 290 kN for 120 137 through 160

Maximum operating speed – 200 kph (125 mph)

 

 

The model

 

It is interesting to note that for many years, there had not been any really good H0 scale model of this signature Deutsche Bundesbahn locomotive. While there had been more or less acceptable offerings by Trix and Märklin (rather lacking in fine detail and with outdated "pancake" motors but generally well proportioned) on one hand and by Fleischmann (well proportioned but with a horizontally split body marked by an ugly split line) on the other, Lima had also come forward with a 120 in the early 1990s. I but understand this model, while generally good-looking, was, like the majority of Lima models of the time, something of a half-done affair, especially where production quality and choice of materials had been concerned.

In 2013, Italian producer ACME then came to the rescue by offering a newly tooled series of class 120s, comprising both the pre-production 120.0 variant and various different iterations of the 120.1 and even the 120.2 of DB Regio. This model was, in my understanding, much acclaimed and featured ACME’s usual high level of detailing, fine paintwork and lettering, and even a cast metal body.

 

The releases brought forth thus far include these references:

 

60360 – 120 001 in original „TEE” livery with single rooftop busbar and original SBS 80 pantograph variant

60370 – 120 112 in oriental red

60376 – 120 141 in traffic red and with additional frontside grab rails

60379 – 120 208 as utilised by DB Regio

 

In addition, two more variants have been announced:

 

60378 – 120 151 with promotional livery for ZDF Television

70075 – Package of 120 502 and matching Dms322 type baggage van as used by DB Netze for measuring and inspection workings

 

 

 

I myself decided to obtain 60370, as in my impression, the oriental red livery remains the most typical scheme for this class. However, I also decided to „redate” the model, under the assumption of 120 112 having retained the oriental red livery much longer than it actually has – making it something of an „Last Mohican” of the class, as only a handful of 120s have retained the oriental red livery to this date.

 

 

 

dsc091287rj9g.jpg

 

With its angular, unadorned body, the 120 is, in my opinion, a typical piece of 1980s industrial design. In my impression, ACME have done an excellent job at capturing the look and feel of this milestone of electric locomotive design. In many ways, I believe the 120 is their best model to date, offering excellent detail as well as mindfulness for operational requirements, shall we say.

 

 

 

dsc09132qtju9.jpg

 

The cab faces are marked by the typical, small Bundesbahn style headlights and large, rectangular windscreen with two panes. Originally, the windscreen wipers, provided as photo-etched parts on the model, rested horizontally at the bottom of the windscreens, but were later changed to a vertical resting position.

The model has sprung buffers and coupler pockets with extension mechanism.

 

As you may notice, I put on DB AG logos atop the Deutsche Bundesbahn logos provided out of the box. The warning "bib" on the oriental red 120s appeared in two varieties: Originally, this panel reached up to the lower edge of the windscreens, and was later changed to end roughly at the top edge of the centre headlight. However, both varieties continued to exist in parallel.

 

 

 

dsc09129icj25.jpg

 

I am also quite taken by the bogies’ appearance, and that of the wheelsets in particular. Out of the box, the model is equipped with cab access ladders attached to the bogies, but is also provided with a second set of ladders which may be glued into recesses on the inside of the body in lieu of the bogie-mounted ladders. I suppose these body-mounted ladders are only viable for very large curve radii – and for display cabinets.

The lettering here on the Cab 1 side mainly comprises the braking weights table, reading as follows:

 

R+E160175 tonnes

R+E 165 tonnes

P+E 150 tonnes

R 115 tonnes

P 80 tonnes

G 58 tonnes

 

I also treated the model to a hypothetical revision date, reading 18 January, 2008, at the Dessau workshops.

 

 

 

dsc091305ak1y.jpg

 

As you can see, I also lettered the model with EVN running numbers, in this case reading 91 80 6 120 112-8 D-DB. The default lettering was easily removed with a piece of 5,000 grade sand paper.

 

 

 

 

dsc09134jgkoe.jpg

 

The rooftop is nicely appointed with fine detail as well. Note the fairly intricate busbar layout, and the delicate yet functional representations of the SBS 80 pantographs.

 

 

And as usual, I should like to link to a couple of Youtube videos showing 120s at work

 

https://www.youtube.com/watch?v=3BNZeliA-x8

 

https://www.youtube.com/watch?v=hOfjUPxMKRg

 

https://www.youtube.com/watch?v=UIywhVLJlpw

 

 

 

Thanks for reading and I hope you liked this article!

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3 Comments


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Another excellent write-up, thank you!

 

The class 120.1 always seem to elude me when photographing German trains. Anything IC always seems to have a 101 on it!

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thanks for your post. As a newbie to the continental sceine I found your article very interesting both from the prototype and model viewpoints. I just love the quality items the continental model trade deliver.

Craig.

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