Class T458 was developed from earlier class T435, later re-classed 720. 720 058-7 (ČKD 4874/1960) has been preserved at the Railway Museum in Lužna u Rakovnika, Czech Republic; photo taken on June 14, 2008.
Slovakian 721 073-5, photographed in Liptovský Mikulaš on April 13, 2007.
Although ČD have already withdrawn their 721s, some are still in use with private operators. This 721 151-9, operated by RegioJet, was photographed by PetrS at the Praha Smichov station on October 15, 2011. Source: www.commons.wikimedia.org.
Side drawing of class T458 by ČKD (source: AV vol. 2).
Russian ChME2-120 (ČKD 4843/1961) on display at the Moscow Railway Museum; photo taken on November 19, 2015.
In 1953 Czechoslovakian engineering company Českomoravská Kolben Daněk (ČKD) built the prototype of a four-axle diesel-electric locomotive, intended primarily as a replacement for steam engines. It was numbered T434.001; second prototype, T434.002, followed in 1955. Both were powered by a six-cylinder in-line 6S310RD engine, developed from a pre-war design intended for Yugoslavian navy. Initial tests were not entirely successful and numerous modifications had to be introduced. In particular, pneumatic starting system, inherited from the marine version, was replaced by electric one, steam boiler for car heating was removed and electric equipment was redesigned. Due to the increase of overall weight class designation was changed to T436. State railways ČSD intended to order ten T436s, but eventually only six pre-production examples followed, which remained in use until late 1960s. Rather than proceeding with this type, ČSD ordered an improved version, which materialized as class T435 in 1958 (in 1988 re-classed 720). In all, 287 examples were built for state railways, industry and export. Production was terminated in 1961. In Czechoslovakia they were commonly nicknamed ‘Hektor’ – allegedly due to characteristic sound produced by low-rpm diesel exhaust, which reminded someone the barking of a dog of such name. T435.087, built in 1962, featured new trucks of indigenous design that replaced so-called Pennsylvania railroad trucks. This modification improved running qualities and was later adopted in production examples.
Class T435 was followed by its development T458. Its origin can be traced back to 1958, when a Soviet delegation visited ČKD and was impressed by T435 prototypes then under tests. An improved, heavier and faster variant was promptly ordered and two prototypes, classed ChME2 (ЧМЭ2 in Russian script) were delivered to the USSR the following year. Overall layout was retained, as was the prime mover. First 212 examples were built for MPS (Soviet ministry of transport); first five T458s for ČSD were delivered only in 1962. Production lasted until 1973 and totaled 941 examples (details can be found at www.prototypy.cz) in seven sub-variants differing in minor details. Of these, the majority – 522 – went to MPS. Most of them were withdrawn in late 1980s. ČSD obtained 221 examples, plus thirteen for the 1524 gauge; they were known as ‘velký Hektor’, or ‘big Hektor’. In 1988 they were re-classed 721. T458s were also exported to Albania (eight), Eastern Germany (three, to industry), India (80) and Iraq (36). Between 1990 and 1991 ČSD sold twenty 721s to Cuba. In 1999 two examples were sold to German operator Karsdorfer Eisenbahngesellschaft. Czechoslovakian industrial railways took over a number of locomotives originally built for India (two), Iran (20), Iraq (eight) and Poland (seventeen), in all, industrial operators in Czechoslovakia had 56 locomotives of this type. Czech railways ČD have already withdrawn all their 721s, although they still remain in use with private and industrial operators. In Slovakia, ŽSSK still operates twenty 721s as switchers.
The reasons why seventeen locomotives of this type intended for export to Poland were not delivered are unclear. Possibly they were found to offer no significant advantages compared to indigenous SM42 of similar performance. A number of T458s, however, finally found its way to Poland. In 1972 state petroleum company CPN purchased two broad-gauge locomotives of this type (8484/1972 and 8485/1972), which were given ‘Czechoslovakian’ service numbers T458.0508 and T458.0509 – the ones they would have been assigned if impressed into ČSD. In 1997 they were taken over by Naftobazy – a company that operates petroleum products storage depots (since 2006 known as OLPP – Logistic Operator of Liquid Fuels). In 2005 Naftobazy purchased second-hand broad-gauge 721.501 (ex T458.1551, ČKD 8013/1971), which was re-numbered T458.0510. All these three locomotives still remain in use at storage depots in Małaszewicze, Zawadówka and Chruściel. Fourth and last Polish locomotive of this type was standard-gauge 721.509-8 (ex T458.1509, ČKD 6800/1965). It was purchased by SKPL (Association for Local Railway Traffic) and is used mainly in irregular freight traffic.
Main technical data
1) TMa-43/37-4 or TMb-43/37-4 in early production examples.
2) Broad-gauge version (T458.0) shorter by 20 mm.
References and acknowledgments
- MAL, AV vol. 2, LOZD vol. 2;
- Petr Štefek (private communication – thanks a lot!);
- SK, various issues.