JNR DD54 Diesel Locomotive

From left to right: prototype units (1 to 3), full-production units (early style), full-production units (later style with round windows) and the same as a static object.



All the necessary dependencies are either included in the package or are avaible on the DLS. As a disclaimer, the dependencies that are not mine are property of their respective authors.

Besides the three “driveable” variants, the pack includes also an “object” DD54 that can be placed on your layouts as a preserved locomotive, for example in a park.


By the mid-1960s, the Japanese National Railways were pursuing their so-called “smokelessness program”, whose main objective was the as-fast-as-possible complete replacement of steam locomotives with electric or diesel ones. For services on non-electrified lines, JNR had been designing a series of different standard locomotives, each for a different duty (an approach similar to British Rail’s “standard diesel types”). Among those, the B-B-B sulzer-engined diesel-electric class DF50 was designed for mainline freight and passenger services, while the more powerful, modern and versatile B-2-B diesel-hydraulic class DD51 was designed for heavy freight and “road switching” duties; finally, the B-B DD13 was designed for shunting work.

Unfortunately, the DF50s were seriously underpowered (1060 or 1200hp at best), wich meant that the JNR lacked a suitable locomotive for passenger trains. At that time, interest fell on the diesel-hydraulic transmission, wich was already proving successful with the 2200hp-powerful DD51s.
Owning to the good results of the experimental class DD91 of 1962, wich used a West-German Maybach-made motor with Mekhydro torque-converter transmission (both having already been used on British Rail’s Class 35 “Hymeks” and on RENFE’s Class 340 “green torpedos”), JNR finally embarked in the quest of designing a medium-weight diesel-hydraulic locomotive for passenger services.


The new locomotive, to be classified DD54, was to be a single-engined, medium-weight diesel-hydraulic locomotive with a torque converter. It’s 40 units were intended to replace the C57 and C58 steam locomotives on non-electrified lines in the Kansai area.
The DD54 were primarily based on the West German DB Baurehie V160 (later 216 and 218), wich almost perfectly mirrored JNR’s ideas, just with a little addition: instead of a common B-B wheel arrangment, JNR opted for the unusual B-1-B arrangment, wich was basically a B-B locomotive with a central unpowered axle, used to lower the axle load and permit the usage of the locomotive on branchlines with a low axle load limit.

To manufacture the new locomotives, Mitsubishi Heavy Industries acquired the production licenses for both the MD870 motor (renamed by JNR as the DMP86Z type) and the torque converter from Maybach, altough the contract had one fatal clause: JNR and Mitsubishi Heavy Industries were not permitted to make any modification or adaptation to either the motor or the converter.
Production of the DD54s started in 1966, with the first three “prototype” units (distingushable by their top-mounted headlights) being delivered to Fukuchiyama Depot in the same year. After undergoing some test runs in 1967, they entered in regular service, both on “regular” passenger trains on the San’in Main Line and the Fukuchiyama and Bantan Lines and sometimes even on the “Oki” express trains.


On the 28th of June 1968, DD54 n°2 was running one of these services, when between Tottori and Koyama on the San’In Main Line, the universal joint linking the transmission shaft to the front bogey of the locomotive broke, with the transmission shaft immediately falling down on the tracks, getting caught between the sleepers and thrusting the whole locomotive upwards. This incident, later nicknamed the “pole vault crash” (pole vault being the sport where the athlete launches himself up in the air using a long, flexible pole) was the culmination of a series of issues and faults the DD54s had been suffering just months after their entrance in service.

Depsite being binded by the license agreement, wich barred both Mitsubishi and JNR from modifying or adapt either the motor or the converter, and all the previous issues, JNR proceded to order the remaining 37 DD54s anyway, as the national railways were desperate to get rid of the last steam locomotives, in an attempt to improve it’s image, wich had been extensively tarnished by a percieved mismanagement and inefficiency. Furthemore, JNR had to face the growing challenge of the private automobile, a challenge that it could not face with steam locomotives.


The full production units entered service starting from 1968, all assigned at Fukuchiyama Depot; they were largely identical to the prototype units, except for the headlights wich were moved under the front windows. From unit 25 onward, the front windows were also changed, from larger squared ones to more resistent, smaller, rounder ones. In 1971, the last locomotive, DD54 40, left the Mitsubishi Heavy Industries and joined the other 39 at Fukuchiyama depot. With the entrance in servce of the full fleet, issues on the DD54s only multiplicated: the overengineered and complex torque converter kept malfunctioning, motor oil kept overheating and the driving shafts kept breaking.

In 1970 it was discovered (with much anger from JNR), that Mitsubishi had made an error when calculating the resistance of the shaft, meaning that the DD54 were all equipped with too much fragile shafts; all of wich were replaced in the same year (at quite the cost). Things weren’t good on Mitsubishi’s side either, with Mayback stil stubbornly denying the permission for any modification or adaptation to the troubled components, and with Japanese engineers lacking experience with these engines, one of the only possible ways to make major repair works on the motors was to pack and send them to the Maybach factory in West Germany altogheter – a ludicrously expensive and time-consuming operation. Another criticism towards these locomotives was moved from the powerful and very active railwaymens unions, wich rightly claimed that the cab was too uncomfortable for drivers.

Furthemore, even day-to-day maintainance was a problem: the locomotives had to be sent all the way to JNR’s Takatori workshop, wich had a small ad-hoc detachment of Mitsubishi technicians, but with information scarce, and possibly vital communciation with Maybach almost absent, DD54s had to spend most of their service life stored awaiting repairs.


Meanwhile the DD51s (also produced by Mitsubishi, but without foreign-made components and binding license agreements) were proving to be extremely versatile and incredibly reliable and cheap to run and maintain while being also very well liked by railwaymens and with DD54s becoming an ever increasing pain-in-the-butt, JNR began to seriously consider their retirement and replacement with DD51s.
In 1976, JNR’s last steam services were finally abolished, effectively completing the long-awaited “smokelessness” plan, but at quite the cost.
By the mid-1970s, only an handful of DD54s were operable, the rest having been stored or shelved due to serious or unrepairable faults. At the same time, JNR decided to shift from diesel-locomotive-hauled passenger trains to DMUs, meaning that the remaining DD54s were either to be replaced by DD51s or by new DMUs.

The agony of these unlucky locomotives came at an end when the last two DD54s (nos. 12 and 33) were taken out of service on the 14th of June 1978.


With none of the units reaching the legal minimium of 18 years of service life, averaging instead a very low 7 years and 4 months (with the shortest being 4 years and 10 months), DD54s quickly became the subject of a brief but intense and very unpleasant discussions in the Diet (the Japanese Parliment) about wheter or not if JNR was being “well-managed”, especially taking in consideration the tight budget and the company’s rapidly-growing debt.
Things became even sourer when a Japanese Communist Party dietman noticed that at the time of the purchase, the person in charge of the auditing of JNR (a certain Yasujiro Okano) had previously been the president of Mitsubishi Heavy Industries, hinting at a possible meddling and favouritism within JNR’s top brass, wich may have led to the purchase of the troubled locomotives.

By early 1979, the discussion around these locomotives had gradually died down, being replaced by the bigger Douglas-Grumman bribing scandal, thus JNR quietly but quickly prodceded to dismantle all 40 DD54s.
All of the DD54s were scrapped by the 1st of December 1978, with the exception of just one: DD54 n°33 (one of the last to run) was saved from scrapping by the interest Fukuchiyama Depot local branch of a railwaymen union, wich originally intended to preserve it as an example of bad locomotive design. In 1984, DD54 33 was handed over to the Modern Transportation Museum of Osaka. With the closure of the latter in 2014, the locomotive (among many other historical railway vehicles) was moved to the Kyoto Railway Museum, where it has been on display since the opening of the museum itself in 2016.



In some cases, with quite the irony, faulty DD54s had to be often towed by the C57 steam locomotives they were intended to replace.


According to a “railfan legend”, the locomotive’s motor was so loud that JNR secretly supplied all DD54 drivers with earplugs.


Again, the DD54s’ diesel engine was allegedly so loud that for all the (brief) service life of the locomotive, JNR’s Fukuchiyama branch offices were flooded by complaint letters written by those that lived along the railway. In one of these, a farmer claimed that the locomotive’s loud noise scared his chickens so much that they stopped laying eggs.


In the mid-1970s, it was extimated by JNR officials that the maintainance costs of a DD54 were 18 times higher than those of a DD51.



DD54 was the last full-body diesel locomotive to be made in Japan until 1992, when JR Freight introduced it’s DF200 class. It was also the last Japanese locomotive using mostly foreign-manufactured components.



The “static object” locomotive is DD54 33, wich in real-life is the only DD54 unit to have been preserved.



At 60’000 polygons and counting, this is by far my most complex model yet.