RSS Fetcher Posted October 16, 2014 Share Posted October 16, 2014 The locomotive we‘ll be having a look at in this article is very much typical and representative of Italian post-war loco design, and continues to play a major role in Trenitalia‘s locomotive inventory. However, decent models of it had been unavailable until a few years ago, when both ACME and Roco came to the rescue, along with Rivarossi re-running an older model of their own. Specifically, it is the small family formed by the class E.655 and E.656 electrics, with the model I picked representing an E.655. Being mindful of the most powerful locomotives usually requiring six wheelsets at the time, but of locos with long-wheelbase six-wheeled bogies being at a disadvantage on curvaceous older lines, Italian loco builders were very early to adopt the alternative solution of grouping wheelsets into three sets of two rather than two sets of three, introducing this kind of layout on the famous class E.626 electrics which heralded the future dominance of the 3,000 V DC system from the late 1920s onwards. These locos had two four-wheel bogies towards the outer ends, with one additional set of two powered wheelsets being located centrally inside the main frame. In 1937, Ferrovie dello Stato (FS) eventually requested a new type of twelve-wheeled electrics, which was also developed on the basis of the „Tri-Bo“ layout and was called E.636. These locos featured an articulated body and three four-wheel bogies, one of which was obviously located underneath the body joint. Providing a a one-hour power output of 2,100 kW, they proved to be a capable and robust design, which first entered service in 1940 and saw the last locos being retired only in 2006. They also were easily recognised by the doubly folded cab fronts with three windscreens, creating a rather unadorned and brutish appearance. A total of 469 locos was built till production ended in 1962. The E.636 was followed by what was called class E.646. These locos were closely derived from the E.636 and also had a „Tri-Bo“ layout with articulated body, but were about twice more powerful due to being fitted with two traction motors per wheelset. Interestingly, the five prototypes actually adopted the 636‘s body with the three-faced cab fronts, which but was replaced by a simpler, flat front with only two windscreens on the production locos. They were built from 1958 till 1967, with a total of 198 locos having been produced, and the last locos having been withdrawn from scheduled service in 2009. During their career, the fleet of E.646s was eventually split, with 97 locos being dedicated to freight work and re-geared for a top speed of 120 kph rather than 140, along with higher tractive effort. These freight locos were then designated as E.645. As the years went on, FS eventually considered another wave of motive power renewals by the early 1970s, with an eye to offering further extensions of passenger services across the country. Again, a new type of electric locomotive was sought, which was to offer at least the same power output as the previously acquired E.444 Bo‘Bo‘ configured express locos, but to be less complicated on the technical side, and could have a somewhat lower top speed as well. Design work began in 1973, eventually resulting in yet another type of „Tri-Bo“ locomotive, designated E.656. These combined a conventional rheostatic power regulation circuit with contemporary electronic cab instrumentation and control gear, and due to being about ten tonnes heavier than the E.646 offered higher tractive effort. Production eventually ran from 1975 till 1989, with a total number of 461 locos being built in three batches. However, since they were in part built simultaneously at different locomotive factories, they were not numbered coherently, with the 1st batch comprising locos E.656.001 through 104, 159 through 199, 201 through 251 and 252 through 307; the 2nd batch comprising E.656.200 as well as 401 through 550; and the 3rd batch consisting of E.656.551 though 608. There are various internal and external differences between these batches, which include different types of auxiliary system alternators, rearranged headlights from 656.159 onwards, or later locos having fewer sanding units, as well as rectangular buffers on 3rd batch locos. The companies involved in building this class were Casaralta, Reggiane, SOFER and TIBB for the mechanical part, and Ansaldo, Asgen, Ercole Marelli and Italtrafo for equipment. Technical description The two-part body is a self-supporting steel assembly resting atop the bogie bolsters by way of multilayered lateral leaf springs. The bogies themselves have a H-shaped frame, with the wheelsets also being suspended against the bogie frames using leaf springs. The bogies are equipped with motion dampers for better running abilities. The loco‘s body follows the same general outline as that of the E.646, with spacious cabs which have since been refitted with air conditioning units on a large part of the fleet. There is one large oval window as well as one pair of bulleyes per side on each body half, serving to allow daylight into the engine room and internal passageway. The gap between the body halves is shrouded by a rubber bellows. Like the E.646, the 656 has twelve DC traction motors with an output of 400 kW each, meaning that there are two motors per wheelset. This allows both a higher power output as well as a greater range of power control, as the motors can be connected in series up to 30 kph, series/parallel (as two groups of six motors) up to 60 kph, parallel (three groups of four motors) up to 90 kph and super-parallel (four groups of three motors) from 90 kph onwards. The diamond pantographs used on this locomotive are known as the 52 type, which was originally equipped with a curved head, but has a flat head nowadays and is usually referred to as the 52/90 type. Eventually, FS adopted a similar allocation scheme to this class as they had done to the E.646 several years earlier. In 1998, those locos which were primarily allocated to freight work began to be re-geared, reducing their top speed to 120 kph, but again allowing for a significantly higher tractive effort. Similarly to the E.645s, they were then redesignated as class E.655, but retained all equipment required for passenger work – such as the ETS circuit – and can thus be used as backups for passenger services. As it is, the two sister classes have the following technical specifications: Length, width and height – 18.29, 3 and 3.80 m (sans pantographs)/60, 10 and 12.5 ft Bogie wheelbase – 2.85 m/9.4 ft Wheel diameter – 1.25 m/49.2 in. Service weight – 120 tonnes/118.1 long tons Gear ratio – 28:61 for E.656, 23:66 for E.655 Configuration – Bo‘Bo‘Bo‘ One-hour power output – 4,800 kW Initial tractive effort – 249 kN for E.656 prototypes The model As previously indicated, E.655 and E.656 models have been brought forth by ACME, Rivarossi and Roco, potentially providing a broad selection to choose from. It should, however, be kept in mind that the Rivarossi models are technically re-runs of older pre-bankruptcy designs. I eventually elected to obtain an ACME E.655, due to better availability on one hand and because in my impression, it is just slightly more refined in overall appearance. The model we'll be looking at now is thus marketed with reference #60089, representing 655.089 of Trenitalia Cargo. I would pronounce the E.655/656 a typical 1970s design, considering the unadorned appearance with very clean lines. This is captured very well by the model, which on top of it is very well detailed and cleanly painted and lettered. As is common for ACME models, it comes with an extensive add-on parts bag, providing coupler pockets, open and closed bufferbeam skirts, brake pipes, and indeed non-split duplicates of the busbar and pneumatic conduits. Out of the box, the model is outfitted with split variants of either, in order to allow the mid-loco articulation joint to pivot. I might yet investigate how I might bridge the busbar and pneumatic line segments flexibly, though… The cast metal builder's and running number plaques are typical for Italian locomotives, and have been duplicated crisply and legibly on the model (albeit being printed on). E.655.089 was, according to the plaques, built and outfitted by SOFER and Italtrafo. In Italy, it also used to be typical for the gear ratio to be written on locomotive bodies, which is what the "23/66" inscription below the plaques refers to. E.655.089 is among those locomotives to have been refitted with cab air conditioning, to which the lateral grille just atop the solebar is related. Looking closely, the bogies are represented very well, and can also be detailed a bit further by way of non-functional yaw dampers included in the add-on bag. However, they must be fixed with glue and even so are not easily attached, so I left them off for the moment. Also note the RS 4 Codici pickup antennas ahead of the outer wheelsets on Bogies 1 and 3; as well as the "aria condizionata" indication just below the cab side window. On the model, the outer two bogies are powered from a centrally located motor by way of driveshafts It is interesting to note that ACME did not forget representing the windscreen heating wires, or at least the two power supply conductors, in either windscreen. The headlight layout on E.655.089 is the original variant, with small red tail lights below and slightly to the inside of the lower headlights. On the secondman's side, there also is the green "Extra Service" marker light, which by Italian operating customs is (or was) required for highlighting special and other non-regular workings to train controllers at local signal boxes. Rooftop equipment tends to be sparse on classic Italian electrics, with the pair of Type 52 diamond pantographs featuring most prominently. As I mentioned before, I might yet check how I might bridge the gap in the busbar with some flexible rubber tubing or some such material to further enhance the model's excellent appearance even further… View the full article Link to post Share on other sites More sharing options...
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