🚦 S&T Work Flow — Railway Projects
Pre-Execution Stage (Planning & Preparation)
Before starting work, all permissions and materials are arranged.
Key Activities:
- Site Survey & Route Inspection
- Identify station layout, cable routes, signal/point locations.
- Collect approved SIP and Cable Route Plan.
- Material Verification (RDSO-approved materials).
- Site Office & Storage Setup.
- Coordination Meetings with departments.
Drwaings
Railway technical drawings using CAD software and printed plans.
Key Activities:
- Signal interlocking plan
- Cable core plan
- Cable route plan
- Track bonding plan
- Point circuit diagram
- Key lock circuit plan
- Signal wiring diagram
- Shunt signal diagram
- Track circuit equipment layout
- Power drawing
- FTOT Diagram ( particulars )
- Location ( Particulars )
- Location circuit Diagram
- Floor plan ( Optional )
Foundation & Civil Works
Civil preparation for mounting of signalling and telecom equipment.
Key Activities:
- Signal post foundations (CC 1:2:4 / 1:3:6).
- Location box bases, point machine foundation with GI pipe route.
- Cable trench excavation and sand cushioning.
- Route marker stone fixing.
Documents:
- Foundation register
- Cable route sketch
Cable Laying & Termination
The backbone of S&T systems — signal, point, and telecom connections.
Key Activities:
- Laying of Signaling Cables: 10C / 19C / 24C
- Telecom Cable / OFC Laying.
- Cable Termination in location & relay room.
- Insulation & Megger Testing.
Documents:
- Cable Megger Report
- Cable Route Documentation
Installation of Equipment
Now the actual devices are installed and wired for signalling, telecom, and power.
Key Activities:
- Color light signals, point machines, track circuits.
- Relays & panels in relay room.
- Telecom: exchanges, PA system, block instruments.
- Power Supply: IPS, DC-DC converter, earthing, surge protection.
Wiring & Interlocking
Ensures system logic is safe and correct as per approved SIP.
Key Activities:
- Wiring between relays, panels, and field equipment.
- Interlocking logic verification.
- Continuity and relay contact tests.
- Proper tag marking and documentation.
Testing & Commissioning
Testing is done by authorized railway S&T officials under strict supervision.
Key Activities:
- Signal Aspect Testing, Point Operation, Track Circuit Working.
- Cable IR & Continuity Check.
- Voltage Drop & Functional Test with Panel.
- Joint inspection and commissioning.
Documents:
- Signal sighting certificate
- Provisional acceptance report
Documentation & Handover
After successful testing, documents are prepared and handed over to the Railway.
Key Activities:
- Cable route plan (as executed).
- Wiring diagram (as executed).
- Megger & testing reports.
- Material utilization record.
- Safety & completion certificate.