Tunnel cable where evacuation takes forty minutes
Voltcore supplies traction power feeders, signalling cable, station LSZH power cable and EV charging supplies for transport projects.
Rail tunnels create the most demanding version of the cable fire problem. A tunnel kilometres from the nearest portal gives occupants and responders a long evacuation route with no alternative exit, mechanical ventilation doing all the work of smoke removal, and signalling and traction circuits that must behave predictably long after the lighting has failed. That combination drives three requirements at once: low smoke and halogen-free behaviour during fire, circuit integrity for the systems needed to run ventilation and evacuation, and electromagnetic compatibility between traction return currents and signalling frequencies that share the same structure. None of those can be added afterwards, so they belong in the first draft of the schedule.
Voltcore Cable has supplied power, control, instrumentation and renewable energy cable from Yixing, Jiangsu since 2008, operating 32 lines and exporting to more than 60 countries under ISO 9001, ISO 14001 and ISO 45001 management systems. Relevant certifications held include CE marking to CPR EN 50575, RoHS, REACH, and SAA / AS/NZS for designs delivered to that specification. Rail orders typically span MV traction feeders, LSZH station distribution, mineral insulated emergency circuits, screened signalling pairs and EV charging hub cable, all produced in 15–25 working days from Shanghai or Ningbo.
Smoke density, toxicity and acid gas determine whether an evacuation route stays usable. Halogen-free low smoke constructions are the baseline in running tunnels and station public areas, and fire resistant types are required wherever a circuit supports ventilation, lighting or communications during evacuation.
Running rails carry traction return current deliberately, but leakage and stray current also reach cable screens, metallic structures and reinforcing steel. Stray current corrosion and induced voltage at signalling cable both follow from that, so bonding, insulation of the return system and screen earthing must be treated together.
Track support structure transmits continuous vibration, and tunnel segments move slightly relative to each other over time. Supports have to restrain cable without abrading it, and flexible connections are needed at every expansion joint, cross passage and station interface.
Older tunnels seep groundwater, accumulate brake dust and support microbial growth on surfaces. Sealed routing, moisture-resistant bedding and protected termination environments keep contamination away from the conductor strand interface, which is where long-term insulation problems begin.
Depot and hub chargers cycle their cables daily with continuous current at high ambient temperature during summer afternoons. Control pilot cores must remain reliable while the power cores heat and cool, and the assemblies are handled by the public rather than by trained operators.
Selected from 67 types because they match the conditions above, not because they are our best sellers.
Medium voltage feeder from the traction supply point to substation rooms located along the tunnel alignment.
Full specification →Circuit integrity supply to tunnel ventilation fans, evacuation lighting and fire mains pumps during a fire event.
Full specification →Station distribution combining halogen-free construction with fire survival for emergency and essential services.
Full specification →Fire detection loops, public address circuits and wayfinding lighting across platforms and concourses.
Full specification →Screened twisted pairs for signalling interfaces, axle counters, point machine position feedback and control telemetry.
Full specification →Depot charging bay equipment supplying bus and fleet vehicles through Type 2 connectors.
Full specification →Charge point installations where the control pilot and proximity conductors are carried alongside power cores.
Full specification →A light rail extension running through twin tunnels needed distribution and control cable, with ventilation circuits required to remain operational during a fire.
Voltcore supplied halogen-free power cable for station areas, mineral insulated fire resistant cable for the fan and evacuation lighting circuits, and overall screened pairs for signalling interfaces. The MV traction feeder lengths were planned around the mandated joint positions. All items were produced on one schedule in 15–25 working days and shipped from Ningbo with per-tunnel drum marking.
A bus depot converting its fleet required charging connections for many bays plus the wiring for charge controller feedback.
Type 2 Mode 3 charging assemblies were supplied alongside EV cable carrying control pilot and proximity conductors, with the control cores matched to the controllers' signalling specification. Power conductor sizes were reviewed against continuous duty at summer afternoon ambient conditions. Voltcore supported private label packaging and delivered free sample lengths first for connector termination trials.
Examples are illustrative; project references and documentation available on request.
Include cross-section, core count, voltage grade, route length and installation method — those five determine price more than anything else on the page.
Copper sheathed mineral insulated cable such as BTTZ is usually specified for ventilation fans, fire mains pumps and evacuation lighting because circuit integrity is inherent rather than dependent on a wrapping layer. Where the evacuation strategy requires emergency supply to additional equipment, ask for the operating temperature and duration requirement and Voltcore will match it to the appropriate fire resistant or mineral insulated construction.
Running tunnels have the longest evacuation distance and rely entirely on ventilation to remove smoke, so any halogenated material in that space reduces visibility and leaves acidic deposits on equipment the responders need. Specifying halogen-free throughout also simplifies inspection, because there is no boundary where a different construction begins.
The first defence is routing and bonding rather than cable alone. From the cable side, specify screened twisted pairs with adequate screen coverage and decide the earthing point in line with the traction return arrangement. Voltcore can supply individual and overall screened instrumentation constructions and will confirm lay-up and screen coverage against your signalling equipment requirements.
Yes. Charging assemblies with Type 2 Mode 3 connections and control conductor cores can be supplied alongside LSZH sub-mains for the supply infrastructure. MOQ is 500 m per size with lead time of 15–25 working days, and Voltcore provides OEM marking and cut lengths for depot-wide rollouts from Shanghai or Ningbo.
RFQs are answered by an application engineer first. Typical reply within 12 hours, CST working days.