SM31

 

SM31_1

 

SM31-029 (Fablok 10393/1984) from Pol-Miedź Trans, photographed in Polkowice on October 29, 2003.

 

SM31_8

 

SM31-027 (Fablok 10391/1984), also from Pol-Miedź Trans, sporting the company’s new livery; photo taken at the Lubin Górniczy station on May 17, 2006.

 

SM31_9

 

Yet another SM31 from the Pol-Miedź Trans fleet: SM31-028 (Fablok 10392/1984), Lubin Górniczy, June 8, 2006.

 

SM31_2

 

SM31-112 with a draft of empty gondolas passes by the plinthed Ol49-1; Jarocin station, November 11, 2003.

 

SM31_3

 

Another example from PKP: SM31-087, photographed in Krotoszyn on November 26, 2003

 

SM31_4

 

SM31-158 at the Leszno depot; August 2, 2004.

 

SM31_5

 

SM31-119, maneuvering near Sosnowiec Maczki station; photo taken on March 3, 2005.

 

SM31_6

 

Derelict SM31-109 at the Zduńska Wola Karsznice depot; photo taken on April 5, 2006.

 

SM31_7

 

SM31-009, operated by the PRKiL track maintenance company; Bolesławiec, May 17, 2006.

 

SM31_12

 

The same machine at the Węgliniec station. April 27, 2007.

 

SM31_10

 

SM31-081, photographed at the Kraków Płaszów depot on September 9, 2006.

 

SM31_11

 

SM31-057, Rybnik, October 20, 2006.

 

SM31_13

 

SM31-158 was used for switching during the 2007 steam locomotive parade in Wolsztyn; photo taken on April 28.

 

SM31_15

 

SM31-139, PKP, displayed at the railway stock exhibition in Gliwice on June 15.2008. Banners are not standard.

 

SM31_16

 

Slightly derelict SM31 (number unknown), photographed at the Rybnik depot on April 18, 2009.

 

SM31_17

 

SM31-117, Bytom, April 30, 2009.

 

SM31_18

 

SM31-075, photographed at the Ruda Śląska Chebzie station on the same day.

 

SM31_19

 

SM31-111, Ostrów Wielkopolski, July 6, 2009.

 

SM31_20

 

Two locomotives from the PKP Cargo fleet, photographed in Tomaszów Mazowiecki on February 29, 2012: SM31-070…

 

SM31_21

 

…and SM31-150.

 

SM31_22

 

The same location and operator: SM31-113, September 27, 2012.

 

SM31_23

 

Another locomotive from the PKP Cargo fleet: SM31-126, photographed in Zduńska Wola Karsznice on December 9, 2012.

 

SM31_24

 

Another photo taken at the same location: SM31-143, PKP Cargo, May 23, 2013.

 

 

SM31-093, Rybnik, February 6, 2003. Photo by Rafał Roskosz (from my collection).

 

 

SM31-063, Białogard, August 8, 1994. Photo by K.Czaplicki (from my collection).

 

 

SM31-128, photographed in Kostrzyn on May 12, 2001. Photo by Roman Szczeciński (from my collection).

 

 

Two more photos from my collection: SM31-138, location and date unknown…

 

 

…and SM31-040, Rybnik, August 1998.

 

 

SM31-087 (Fablok 10157/1979), Poznań Starołęka, September 16, 1993. Photo by Marek Niemiec (from my collection). This locomotive still remains in use with PKP Cargo.

 

 

SM31-046, PKP (Fablok 9935/1978), Rybnik, June 1998. This locomotive was written off in September 2012. Photo by Mariusz Plewka (used by permission).

 

 

SM31-052, PKP Cargo, photographed in Sokołów Podlaski on October 20, 2017.

Withdrawals of steam locomotives used for switching resulted in a need for a heavy diesel switcher, for both PKP and industrial establishments. This led to purchases of as many as four distinct locomotive types, all in the 1200 hp class: Czechoslovak T448P and S200, built by ČKD (161 and 143 examples, respectively, delivered between 1966 and 1990, all for industry), Soviet TEM2 (SM48 in PKP service, 439 examples delivered between 1974 and 1990 from Bryansk and Lugansk) and indigenous SM31, built by Fablok of Chrzanów.

SM31 (factory designation type 411D) drew on experience gained with earlier SM42, but differed considerably from its predecessor, both externally and internally. First of all, it had the Co’Co’ axle arrangement, was longer by almost three metres and heavier by 60%. Engine and electric equipment compartment cowlings had the same height as the cab and the entire silhouette was more angular, which promptly resulted in the nicknames ‘trumna’ (coffin) or ‘szafa’ (wardrobe), widely used in service. With such layout, forward view was rather restricted. Eight-cylinder a8C22W diesel engine was of the same type as in SM42, but boosted up to 1200 hp by higher supercharging. Three-axle trucks were similar to that used in SP45 and SU46 diesel locomotives from Cegielski (HCP). SM31 design facilitated easy re-gauging to the 1524 mm track, but there is no information of any such operation being actually performed. They could also be fitted with the SA3 automatic coupler, standardized with Soviet railways.

Design of SM31 was completed in 1973 and first three production examples were delivered to PKP in 1976. Until 1985, state railways received 167 locomotives of this type from Fablok, numbered SM31-003 through SM31-169. Furthermore, thirty machines (including two prototypes, SM31-001 and SM31-002) went to various industrial operators between 1977 and 1984. They were designated SM31, 411D or Ls1200P. Due to three-axle trucks and comparatively long axle base, they had some problems with negotiating tight curves, so many industrial operators tended to prefer less powerful, but more versatile SM42s. One example (Ls1200P-011) was sold to PKP in December 1988, to become SM31-170. At least five SM31s from industry were written off and scrapped between 2000 and 2005.

In February 2019 PKP Cargo had 82 examples, probably not all of them operational. Most of them were based in Upper Silesia and hauled heavy freight trains between collieries or steelworks and switch yards. Until early 2023 they dwindled in number to 24. The rest were withdrawn or scrapped, except for three examples (SM31-111, -130 and -158) sold to various private operators. Of industrial operators, the largest fleet was that of Pol-Miedź Trans (PMT) company, which had four examples inherited from the company’s predecessor, KGHM, all built in 1984. Two more were later leased. These six locomotives were in fact the last SM31s built. Initially numbered 411D-025, Ls1200P-026 and 411D-027 through 030, they were later re-classed SM31, retaining their service numbers. Three of them were withdrawn in 2016 and scrapped. The remaining three were sold to private operators; two still remain in use, while SM31-028 has been dumped in Nowy Sącz. It has to be noted that in several cases identical service numbers were assigned to two different locomotives, one from the PKP Cargo fleet and the other one owned by an industrial or private operator; this was the case with all PMT vehicles. Contrary to several other types, SM31 underwent no modernization.  

 

Main technical data

 

No.

Parameter

Unit

Value

1.

Years of manufacture

-

1976 – 1984

2.

Total built / used in Poland

-

1971)

3.

Axle arrangement

-

Co’Co

4.

Transmission type

-

electric

5.

Design maximum speed

km/h

80

6.

Prime mover type

-

a8C22W

7.

Engine rating

kW/hp

882 / 1200

8.

Bore x stroke

mm x mm

220 x 270

9.

Number of cylinders

-

8

10.

Number of electric engines

-

6

11.

Rated output of electric engines

kW

6 x 196

12.

Main reduction gear ratio

-

 

13.

Diameter of drivers

mm

1100

14.

Total weight

kg

116 400

15.

Axle load

T

19.4

16.

Axle base

mm

12 350

17.

Overall length

mm

17 000

18.

Maximum width

mm

 

19.

Train heating

-

-

20.

Brake type

-

Oerlikon (?)

 

1)     Including 167 for PKP.

 

List of vehicles can be found here.

 

References and acknowledgments

 

-       AL, LSPP;

-       SK (various issues);

-       www.ilostan.forumkolejowe.pl;

-       www.kolejowaklatka.org.