{
  "ftaDoc": {
    "version": "5.0",
    "standard": "IEC61025",
    "savedAt": "2026-03-10T03:38:07.485325Z"
  },
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      "name": "Rail \u2014 Train Control",
      "expanded": true,
      "settings": {
        "description": "Fault tree analysis for SPAD \u2014 train passing a stop aspect signal without authority. Developed against EN50126, EN50128, EN50129 with CENELEC risk analysis framework. Addresses signalling failure, ATP failure and driver error pathways.",
        "organization": "FTA Studio Template Library",
        "analyst": "",
        "revision": "A",
        "standard": "IEC61025",
        "silTarget": "SIL4",
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        "anaMethod": "exact",
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      "ftas": [
        {
          "id": "f2f1762c2",
          "name": "Signal Passed at Danger (SPAD)",
          "nodes": [
            {
              "id": "n1458b823",
              "uid": "TOP-001",
              "ntype": "top",
              "gateType": "OR",
              "name": "Train Passes Signal at Danger (SPAD)",
              "desc": "Train proceeds past a stop aspect signal without authority. Ref: EN50126, EN50128, EN50129. Risk category: Catastrophic/Frequent \u2192 requires risk reduction to Tolerable.",
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              "uid": "BE-001",
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              "name": "Signal lamp / LED unit failure",
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              "lambda": 5e-05,
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              "failureMode": "Dark signal \u2014 no aspect displayed",
              "detection": "Lamp proving circuit, central monitoring",
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              "occurrence": null,
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            },
            {
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              "uid": "BE-002",
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              "lambda": 2e-06,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "Wrong aspect output",
              "detection": "Vital relay cross-checking; double-check output monitoring",
              "hazards": [],
              "evidence": "",
              "mitigation": "Safety-certified relay logic with vital proving",
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              "occurrence": null,
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              "id": "nd178f704",
              "uid": "BE-003",
              "ntype": "basic",
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              "name": "Signal cable / wiring fault",
              "desc": "Wiring failure between interlocking and signal head \u2014 short, open or earth fault.",
              "outputId": "n7eba46b5",
              "refId": null,
              "prob": null,
              "lambda": 1e-06,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "Loss of control signal to lamp",
              "detection": "Lamp proving circuit detects open/short",
              "hazards": [],
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              "mitigation": "Cable route protection; periodic inspection",
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              "ntype": "basic",
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              "name": "Balise / transponder reader fault",
              "desc": "On-board antenna/reader fails to correctly receive Eurobalise telegram.",
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              "failureMode": "No data reception from balise",
              "detection": "Data integrity check on received telegram",
              "hazards": [],
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              "mitigation": "Two independent balise readers per train (redundancy)",
              "severity": null,
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              "y": 590
            },
            {
              "id": "ne6051f62",
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              "ntype": "basic",
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              "name": "On-board ATP computer fault",
              "desc": "On-board vital computer \u2014 hardware fault in processor or I/O.",
              "outputId": "n6c31ea51",
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              "prob": null,
              "lambda": 3e-07,
              "mu": null,
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              "sil": null,
              "failureMode": "No brake command output",
              "detection": "Dual processor comparison; watchdog",
              "hazards": [],
              "evidence": "",
              "mitigation": "Fail-safe: loss of ATP output triggers service brake",
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              "occurrence": null,
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              "x": 500.0,
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            },
            {
              "id": "n3f518600",
              "uid": "G-004",
              "ntype": "gate",
              "gateType": "OR",
              "name": "Emergency Brake Failure",
              "desc": "Emergency brake fails to stop train within required distance.",
              "outputId": "nfbebe4c5",
              "refId": null,
              "prob": null,
              "lambda": null,
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            },
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              "uid": "BE-006",
              "ntype": "basic",
              "gateType": null,
              "name": "Brake pipe pressure application failure",
              "desc": "Emergency brake application via brake pipe pressure dump fails.",
              "outputId": "n3f518600",
              "refId": null,
              "prob": null,
              "lambda": 2e-07,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "Brakes do not apply on dump",
              "detection": "Brake test at depot; in-service diagnostics",
              "hazards": [],
              "evidence": "",
              "mitigation": "Fail-safe pneumatic design: brakes apply on pressure loss",
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              "occurrence": null,
              "detectability": null,
              "x": 660.0,
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            },
            {
              "id": "n3caa006f",
              "uid": "BE-007",
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              "name": "Compressed air supply failure",
              "desc": "Compressor or main reservoir failure resulting in inadequate air supply.",
              "outputId": "n3f518600",
              "refId": null,
              "prob": null,
              "lambda": 1e-07,
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              "missionTime": 8760,
              "sil": null,
              "failureMode": "Insufficient air pressure for braking",
              "detection": "Main reservoir pressure gauge / warning",
              "hazards": [],
              "evidence": "",
              "mitigation": "Low pressure inhibits train departure",
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              "occurrence": null,
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            },
            {
              "id": "n46229a4d",
              "uid": "G-005",
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              "gateType": "AND",
              "name": "Driver Error Leading to SPAD",
              "desc": "Driver fails to observe signal AND fails to apply brakes in time.",
              "outputId": "n1458b823",
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            {
              "id": "ne5dd7d08",
              "uid": "BE-008",
              "ntype": "basic",
              "gateType": null,
              "name": "Driver fails to observe stop aspect",
              "desc": "Human error \u2014 driver distraction, fatigue, or signal sighting issue.",
              "outputId": "n46229a4d",
              "refId": null,
              "prob": 0.001,
              "lambda": null,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "Signal not seen or misread",
              "detection": "CCTV, driver vigilance device",
              "hazards": [],
              "evidence": "",
              "mitigation": "Driver reminder system (DRS); SPAD indicator boards",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": 980.0,
              "y": 420
            },
            {
              "id": "nc902cafa",
              "uid": "BE-009",
              "ntype": "basic",
              "gateType": null,
              "name": "Driver fails to apply brakes in time",
              "desc": "Given signal observed, driver does not apply adequate braking in time.",
              "outputId": "n46229a4d",
              "refId": null,
              "prob": 0.0001,
              "lambda": null,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "Reaction delay exceeds available stopping distance",
              "detection": "ATP back-up provides automatic intervention",
              "hazards": [],
              "evidence": "",
              "mitigation": "Train speed profile management; reduced speed at SPAD risk signals",
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              "occurrence": null,
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          ],
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}