As a part of the 1970s-programme to modernise the Cuban sugar industry, Russia sent light diesel locomotives to Russia. At this periode of time, the Kambarka factory in Russia had just started the serie production of a standardised four-axle bogie dieselhydraulic locomotive.
This type is known as the class TU7. T stands for "Teplovoz" (diesel locomotive); U for "Uzkokolej" (narrow gauge) and 7 simply indicates that this is the seventh type of narrow gauge diesel locomotive in Russia. Most components are of a standardised design. Kambarka-built class TU6, TU6A, TU6P, TU8, TU8P and TGM40 diesel locomotives very much look the same as a TU7.
Serie production of the class TU7 commenced in 1972 and continued until 1988. The modernised version (TU7A) has even been constructed until Summer 1994. Between 1970 and 1994 at least 3220 locomotives of these types rolled out of the factory.
Most TU7s went to 750mm gauge industrial, forestry and peat railways throughout the Soviet Union. Dozens worked on 750mm gauge public railways, where they should replace the well-known class TU2 diesel locomotives, but did not succeed in doing so. Today many TU7s and the somewhat modernised and more powerfull TU7A can be found in countries which used to be part of the USSR.
In late 1974 Kambarka also started to export this class to Cuba. TU7s intended for export were numbered as class TU7E (the added E standing for Export). Noticeably some publications speak of the class TY73, which can be explained as a false transliteration of the cyrillic characters.
The running numbers are independent of the class designation. If a TU7 was exported, only "TU7" was replaced by "TU7E" and the locomotive kept its original running number. The running numbers may be interpreted as factory numbers withing a specific type of locomotive and all its subtypes (in this case the classes TU7, TU7E, TU7A and TU7AE). Kambarka also exported TU7s to other countries.
Parameters of the class TU7E in Cuba
|
Principal dimensions Length of the body Width of the body Height above head of rail Distance between bogies Base of bogies Diameter of wheels Minimum curve radius Total weight Axle-load Possible gauges |
9.400 mm 2.450 mm 3.550 mm 4.700 mm 1.400 mm 600 mm 40 m 24 tons 5 tons 705 - 1435 mm *1) |
|
Speed Maximum speed |
50 km/h |
|
Diesel engine Type Rated power Operating speed |
Bernaul 1D12-400, 12-cilinder, V-shaped 400HP 500 - 1560 r/min |
|
Transmission Type Wheel formula |
hydraulic (UGP400-650) B'B' |
*1) TU7E's could be supplied with standard bogies for 750-1067mm; the 705mm and 1435mm gauge bogies seen under some TU7E's in Cuba are custom-made. In some cases the boogies have been regauged following the regauging of the network the locomotive worked on.
According to Chris Capewell CUba also received 5 class TGM25 diesel engines (MINAZ 34036-34040). This is the broad-gauge version of the TU7 but they run on standard gauge in Cuba.
A factory photo of TU7E-340 in the Russian snow. This loco was clearly intended for export to Cuba as it features a large MINAZ-logo. It is speculated that this was the first loco exported to Cuba.
The control panel of a Cuban TU7E with cyrillic characters.
Later MINAZ renumbered its TU7s as class 34000. It is not known which TU7E have been exported to Cuba nor do we have a renumbering scheme. Judging by the MINAZ numbers, 85 class TU7E must have been delivered to Cuba (known running numbers 34001 - 34085). Only from the following TU7s their original numbers are known:
| Kambarka number | year | MINAZ number |
| TU7E-0340 | 1974 | ? |
| TU7E-0457 | 1975 | ? |
| TU7E-0472 | 1975 | 34026 |
| TU7E-0473 | 1975 | 34027 |
| TU7E-0474 | 1975 | 34028 |
| TU7E-0475 | 1975 | 34029 |
| TU7E-0476 | 1975 | 34030 |
| TU7E-0671 | 1976 | 34048 |
| TU7E-0676 | 1976 | ? |
| TU7E-0842 | 1977 | 34065 |
| TU7E-0857 | 1977 | 34075 |
| TU7E-0868 | 1977 | 34085 |
Judging by the sequence of the Kambarka and MINAZ numbers, it seems the locos have been renumbered 34001 - 34085 in order of their original Kambaraka numbers. If so, the construction years of all class TU7E can be narrowed down to a very short period: 1974-1977.
In Cuba the class TU7E worked on lines with different gauges: 705, 762, 914 and 1435 mm. The numbers of the narrow gauge engines were often preceded by an "E". This did not mean "Export" as in TU7E, but instead "via Estrecha" which is Spanish for narrow gauge.
The TU7E worked along side ancient steam engines instead of replacing them. Only in the end the class TU7E has outlived its collegue steam locos. But these diesels are now also 30 years old and only one quarter of the locos delivered to Cuba are still in use (±25 out of 85). Given the poor quality of the Russian diesels, it is remarkable that there are still operational TU7s in Cuba. A compliment is on its place for the Cuban engineers who have managed to keep them running. Their Russian collegues have not been so succesfull and in fact many TU7s (even from the most recent production series) have been dumped. Of course the dry and warm climate also explains the relative long life of the TU7s in Cuba.
In 2004 class TU7E diesels could be found on sugar railways in the following provinces:
| Province | Active TU7Es |
| La Habana | 2 |
| Matanzas | 3 |
| Cienfuegos | 6 |
| Villa Clara | 8 |
| Sancti Spiritus | 3 |
| Ciego de Avilla | 1 |
| Holguin | 1 |
| TOTAL | 24 |
In addition 34012 is used on the pioneer railway in the Camilio Cienfuegios Park in Camaguey. Also see the TU7E-roster.
