Piko 52313 H0 - SM31 Diesel Locomotive, PKP, Era IV, DCC with sound

Digital SM31 heavy diesel shunter model in Polish State Railways livery

A digital model of the SM31 diesel locomotive — the six-axle machine from Fablok, designed as a more powerful complement to the widespread SM42. The version reproduced by PIKO represents an era V setting and comes with a factory-fitted sound decoder.

The model reproduces the distinctive outline of a heavy shunter with its long hood and offset cab. Four axles are driven and two wheels carry traction tyres, giving pulling power suited to long freight formations on a layout. The factory-fitted PIKO sound decoder in PluX22 standard reproduces engine sounds and controls digitally switchable cab lighting.

Model specifications:

• Scale: H0 (1:87)
• Catalogue number: 52313
• Manufacturer: PIKO
• Model length: 195 mm
• Era: V
• Power supply: DC
• Decoder socket: NEM 658 – PluX22
• Decoder: PIKO sound decoder, factory-fitted
• Traction tyres: 2
• Coupling: NEM 362 coupler pocket with close coupling kinematics
• Minimum radius: 358 mm
• Lighting: lights changing with the direction of travel: white and red
• Digitally switchable cab lighting
• The model is painted and ready to run
• Recommended age: 14 years and over

Please note: a DCC command station and powered track are required to operate this model.

The model is not a starter set and does not include track or a controller. To use all the digital functions — sound and independent lighting control — a DCC command station is required (for example the PIKO SmartControl or any other DCC-compatible controller) connected to powered track. The model can also be run on a conventional analogue DC layout, but only provided that the decoder has the alternative power source function enabled (analogue operation — controlled in the DCC standard by bit 2 of register CV29). It is active by default, but if it has previously been switched off, applying DC to the track may damage the decoder. In analogue mode only basic running is available — without sound or digital functions.

Model railways – digital or analogue control?

The digital DCC control system allows several locomotives to run independently on the same track. Each vehicle receives individual commands while the rail voltage stays constant, which makes realistic operation possible and allows the lights and sound effects of every locomotive to be controlled separately. In an analogue system all vehicles on a given circuit are controlled at once by varying the supply voltage. PIKO model 52313 has a factory-fitted sound decoder and is intended above all for digital operation.

About the SM31:

The SM31 was designed by Fablok as a more powerful complement to the SM42 — a machine for heavy hump shunting at large yards and in industry, particularly the Upper Silesian coal mines. It used the same engine lineage as the SM42 but in a turbocharged, intercooled version rated at 880 kW, together with a six-axle layout on two three-axle bogies that gave high tractive effort at a weight of over 116 t.

In practice the locomotive disappointed in its intended role: the turbocharged engine coped badly with the idling and constant load changes typical of shunting, and the tall hood restricted visibility despite the enlarged cab. The SM31 proved far better suited to light and medium main-line work — hence the description of the class as a shunting and trip locomotive.

Production ran from 1976 to 1985; sources give around 190 units in total, of which close to 170 went to PKP and the remainder to industry. The machines still work today in Upper Silesia and around Łódź, Poznań, Szczecin and Wrocław. Modernisation programmes have run since the 2000s, including the SM31-2000 family with a new engine and control system.

Prototype specifications (SM31, Fablok type 411D):

• Manufacturer: Fablok Chrzanów, type 411D
• Built: 1976–1985
• Output: approx. 190 units, of which close to 170 for PKP
• Wheel arrangement: Co'Co'
• Length: 17,000 mm
• Service weight: 116.4 t
• Engine: a8C22W rated at 880 kW, electric transmission
• Top speed: 80 km/h
• Role: heavy shunting in marshalling yards, ports and industry; light freight trains

About the manufacturer – PIKO:

PIKO is a German manufacturer of model railways with more than seventy years of tradition, founded in 1949 in Sonneberg. Today it is one of the most popular model railway brands in Europe and a leading producer of Polish prototype models, including locomotives and coaches in PKP, PKP Intercity and PKP Cargo colours. The range covers H0, TT, N and G scales, from individual wagons to comprehensive starter sets and digital control systems. The PIKO Expert range combines a high level of detail with modern digital technology — with factory-fitted DCC and sound decoders in selected models. PIKO products are valued by modellers and collectors worldwide.