Diesel locomotive BB 63901 R37

Original page created on 30/08/2023; last modified on 30/09/2023.

Brand - Reference

R37 HO41111


BB 63901


221 g

Current @ 12 V DC, before running in

  • At slipping: 0.32 A (fwd) / 0.28 A (rev)
  • Blocked motor: 0.6 A


I might as well say it straight away : I’m going to be severe given the price of this machine: €280 (in pure DC).

The locomotive is well proportioned, as confirmed by the dimensions table. It feels very light in the hand, and indeed it is (221 g compared with 285 g for the Roco). The handrails are slim and made of flexible material. Articulated screw couplings with a resting hook are supplied, but no simplified hook allowing the joint use of elongation drawbars. By the way, these drawbars can be easily removed (2 screws) if you no longer wish to see the bulky NEM boxes.

Numerous inserted parts, plastic (acoustic cornets, various hooks, windscreen wipers) and metal (bonnet rails and grilles, lifting rings). Beware: some are poorly fixed and can easily slip out (it happened for a grille of the long bonnet, found by chance, and the acoustic cornets).

As reported on the Loco-Revue forum, the machine is “bowed”, by about 0.5 mm. This deformation almost disappears by loosening the body fixing screws, but as they were not very tight originally, they are now somewhat loose. Let’s hope they won’t slip out.

The cab is fitted out, with a nice, fairly detailed console.

The body, decking and external chassis (side beams and buffer beams) form a single piece that can be dismantled with four screws. The interior reveals clean wiring, with multiple spring-loaded pins to connect the PCB attached to the internal chassis, to the various lighting fixtures attached to the body. The motor is fitted with two flywheels. Photo.Dismantled machine

Now for the long list of annoying little flaws:

  • a buffer popped out when I was removing the standard couplings (why were they fitted?), and I can’t get it back in place, as if its housing was half blocked;
  • the left-hand railing on the large bonnet side has a curious deformation, the cause of which is not easy to determine. The decking also appears to be deformed. Photo;Railing — or decking — deformed
  • A registration plate is glued on slightly crookedly, and traces of glue can be seen around it. In addition, these registration plates are simply stamped, whereas REE offers photo-etched plates as detail items, which is not the case here. Photo. What’s more, they are positioned too high (thanks David): compare with the photos of the actual machines;Plate glued crooked
  • the horns are not hollow;
  • the headlights look upwards. Photo. Secondly, they are fitted with two separate LEDs, whereas bi-colour LEDs are available in a compatible size. What’s more, they are not arranged symmetrically in relation to the machine’s plane of symmetry. Finally, it would have been better if they were on a vertical axis. Photo;Headlights looking upwardsBuffer beam
  • for the buffer beam equipment, apart from the lack of a simplified hook already mentioned, some brake hoses fit well: those whose mounting hole corresponds to their tenon, which is square… For the others with a square tenon too, but with a round mounting hole, you’ll have to explain to me how to square the circle… See the previous photo;
  • There’s nothing in the instructions about dismantling the wheelsets, and there’s no obvious way of dismantling the bogie housings.

I’ll stop here. For my first purchase from R37, I’have rather mixed feelings.


  • the Loco-Revue forum;
  • gamos81.altervista.org for the list of the BB 63000 references released in scale models, but forgetting the 63500 R37. On the other hand, there is a long list of LS Models that will probably never be released…


These modifications mainly involve repairing the model’s minor blunders. The photos opposite were taken after the modifications.

  • Acoustic cornets, bonnet grille and buffer glued back.
  • Brake hoses installed by making round holes square.
  • Vertical deformation of the railing corrected by discreetly cutting the excessively long upright.
  • Headlights and handrails straightened.
  • Installation of an ESU Lokpilot 5 DCC PluX22 decoder. Contrary to some fears, this decoder does not interfere with putting the body back in place. Programming this decoder is rather complicated because the four white lights are connected separately to four outputs, two of which are traditionally used for the red lights (AUX1 and AUX2). The latter are relegated to the AUX3 and AUX4 outputs:
    Output correspondence
    Use ESU output Zimo output
    White Ft L Front light
    White Ft R Rear light
    White Rr L AUX1 FO1
    White Rr R AUX2 FO2
    Red Front AUX3 FO3
    Red Rear AUX4 FO4
    Cab AUX6 FO6


580 locomotives built between 1956 and 1971 by Brissonneau et Lotz - Sulzer - S.A.C.M. Power 450 kW (diesel 610 kW). Maximum speed: 90 km/h. Weight 68 t.

The 63901 is one of four “heating” machines (63896, 63901, 63902 and 63906) at the La Plaine depot, fitted with an alternator in 1965 to heat passenger trains connecting the Gare du Nord and Gare de Lyon stations on the Petite Ceinture round Paris. The maximum authorised load was seven coaches (or more with reduced heating). Weight 70.4 t. 400 kVA alternator (source: DocRail).

The BB 63901 was brought into service on 28 December 1964 at La Plaine. Successive depots: Avignon in October 1980, Strasbourg in June 1982, Nîmes in January 1986, Avignon in November 1987. Written off on 18 May 2012 (sources: Trains du Sud-Ouest and EC64).


  • Loco-Revue sheet No. 29 / 64 c 3 (older series).
  • Loco-Revue diagram No. 1752 of the 040-DE (63000) series. Size 400 × 280 mm. Diagram preview.
  • Assignments at EC64.
  • Park at Trains du Sud-Ouest.
  • Photos on RailFanEurope.
  • Ferrovissimo No. 4 of July 2005 BB 63000 : la 2 CV du rail !
  • Ferrovissime special issue No. 6 of 2016 Les locomotives diesel mixtes et de manœuvre, p. 76 to 89.
LR diagram

BB 63901 R37, long bonnetBB 63901 R37, long bonnet

BB 63902, long bonnet

Cliché B. et H. Ruetsch sur DocRail.

BB 63901 R37, short bonnetBB 63901 R37, short bonnet

BB 63901, short bonnet

Photo J.-H. Lavie in Ferrovissimo No. 4, p. 14.

Dimension Actual 1:87 Model
Overall length 14 780 169.9 170.5
Chassis length 13 500 155.2 154.8
Width 2 800 32.2 32.3
Width of long bonnet 1 720 19.8 20.0
Height 3 980 45.7 45.3
Height of long bonnet 3 380 38.9 38.7
Pivot distance 7 500 86.2 86.2
Bogie wheelbase 2 600 29.9 29.9
Wheel diameter 1 050 12.1 12.0
0.8 14.3  
to 14.5 1
  1. NEM: 14.5 ± 0.1.

Document available as a PDF.
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For conditions, see page
Loco-Revue documentary sheets. .