SPFB Speed Control System Cables


Applications :

  • The cables are used for the train speed control system (French system KVB). The cables are laid along railway lines and connect the speed sensors (located between the rails) to the encoder located inside the trackside equipment shelter.

Standards :

  • SNCF CT 446


Construction :

  • Conductors : Class 2 stranded tinned copper.
  • Insulation : Solid polyethylene.
  • Cabling Element : Twisted pair.
  • Inner Sheath : Low density polyethylene.
  • Armour : Galvanized steel braid armour.
  • Outer Sheath : Flame Retardant PVC.

Electrical Characteristics at 20 °C :

  • Nominal Conductor Diameter mm 0.8
    Nominal Cross Section Area mm2 0.5
    Maximum Conductor Resistance (DC) Ω/km 36
    Characteristic Impedance @100KHz Ω 120
    Maximum Attenuation @50KHz dB/km 5
    Nominal Insulation Thickness mm 0.55
    Operating Voltage V 500

Mechanical and Thermal Properties :

  • Minimum Bending Radius : 8×OD (static); 16×OD (dynamic).
  • Temperature Range : -30°C to +70°C (during operation); -20°C +50°C (during installation).

Dimensions and Weight :


Cable Code No. of cores& Nominal
Conductor Cross
Sectional Area
No. & Nominal
Diameter of
Nominal Sheath Thickness
Nominal Overall
Nominal Weight
Inner Outer
RS/SPFB-2Y2Y(SWB)2Y-2C0.5S 2 x 0.5 7/0.32 1.0 1.5 9.1 97




Ozone Resistant
Fuel Oil Resistant
Mineral Oil Resistant
Laid In Ducts/ Channel
Flame Retardant
NF C32-070-2.1(C2)
IEC 60332-1/EN 50265-2-1