{
  "edition": "2026-11-07",
  "id": "doctor-yellow-923",
  "locale": "en",
  "url": "https://senroam.com/en/trains/doctor-yellow-923/",
  "name": "923 · Doctor Yellow · T4 / T5",
  "summary": "923 · Doctor Yellow · T4 / T5 · Inspection train. A 700-series-derived broad bill.",
  "type": "train",
  "questions": [
    {
      "id": "doctor-yellow-923-q1",
      "question": "Did both 923 sets retire in January 2025?",
      "answer": "JR Central’s T4 made its last inspection run on 29 January 2025. JR West’s T5 continued the Tokyo–Hakata inspection, including the Tōkaidō section east of Shin-Osaka. As of 7 November 2026, JR West plans to finish T5 inspections in January 2027.",
      "evidence": [
        {
          "title": "ドクターイエロー（T4編成）部品オークション・車両解説",
          "url": "https://market.jr-central.co.jp/shop/pages/s983_t4auction.aspx",
          "publisher": "JR東海",
          "lang": "ja",
          "date": null,
          "page": null,
          "checked": "2026-11-07"
        },
        {
          "title": "ドクターイエロー（Ｔ４編成）引退に伴うイベント等の実施について",
          "url": "https://jr-central.co.jp/news/release/_pdf/000043982.pdf",
          "publisher": "JR東海",
          "lang": "ja",
          "date": "2024-12-12",
          "page": 1,
          "checked": "2026-11-07"
        },
        {
          "title": "500系新幹線＆「ドクターイエロー」Ｔ５編成の引退について",
          "url": "https://www.westjr.co.jp/press/article/2026/06/22/items/260622_00_press_500kei_dryellow.pdf",
          "publisher": "JR西日本",
          "lang": "ja",
          "date": "2026-06-22",
          "page": 1,
          "checked": "2026-11-07"
        }
      ],
      "sources": [
        "https://market.jr-central.co.jp/shop/pages/s983_t4auction.aspx",
        "https://jr-central.co.jp/news/release/_pdf/000043982.pdf",
        "https://www.westjr.co.jp/press/article/2026/06/22/items/260622_00_press_500kei_dryellow.pdf"
      ]
    },
    {
      "id": "doctor-yellow-923-q2",
      "question": "Can I look up T5’s last inspection in a timetable?",
      "answer": "JR West says it will withhold inspection schedules, including the final inspection date. Separately announced events are the exception. The January 2027 notice gives a planned month; it makes no promise about a particular day or station.",
      "evidence": [
        {
          "title": "500系新幹線＆「ドクターイエロー」Ｔ５編成の引退について",
          "url": "https://www.westjr.co.jp/press/article/2026/06/22/items/260622_00_press_500kei_dryellow.pdf",
          "publisher": "JR西日本",
          "lang": "ja",
          "date": "2026-06-22",
          "page": 1,
          "checked": "2026-11-07"
        }
      ],
      "sources": [
        "https://www.westjr.co.jp/press/article/2026/06/22/items/260622_00_press_500kei_dryellow.pdf"
      ]
    },
    {
      "id": "doctor-yellow-923-q3",
      "question": "Why does a 923 resemble a 700 series, and what changed underneath?",
      "answer": "The passenger 700 series supplied the starting design. To inspect at 270 km/h, the 923 adopted a 25 m track-measuring car running on two bogies. Laser measurement replaced the earlier system that determined track displacement from the physical positions of three bogies.",
      "evidence": [
        {
          "title": "世界に誇る安全な新幹線を守ってきた「ドクターイエロー」の歩みを振り返る",
          "url": "https://www.tetsudo.com/report/481/",
          "publisher": "鉄道コム（栗原景）",
          "lang": "ja",
          "date": "2025-01-26",
          "page": null,
          "checked": "2026-11-07"
        },
        {
          "title": "ドクターイエロー（T4編成）部品オークション・車両解説",
          "url": "https://market.jr-central.co.jp/shop/pages/s983_t4auction.aspx",
          "publisher": "JR東海",
          "lang": "ja",
          "date": null,
          "page": null,
          "checked": "2026-11-07"
        }
      ],
      "sources": [
        "https://www.tetsudo.com/report/481/",
        "https://market.jr-central.co.jp/shop/pages/s983_t4auction.aspx"
      ]
    },
    {
      "id": "doctor-yellow-923-q4",
      "question": "What were the little roof domes on T4 for?",
      "answer": "From the observation domes on cars 3 and 5, staff could watch the pantograph meet the contact wire. A camera at the observation position also fed pictures to the electrical inspection room in car 1. Car 4 handled a different signal entirely: its screens plotted track geometry as the train ran.",
      "evidence": [
        {
          "title": "ドクターイエロー（T4編成）部品オークション・車両解説",
          "url": "https://market.jr-central.co.jp/shop/pages/s983_t4auction.aspx",
          "publisher": "JR東海",
          "lang": "ja",
          "date": null,
          "page": null,
          "checked": "2026-11-07"
        }
      ],
      "sources": [
        "https://market.jr-central.co.jp/shop/pages/s983_t4auction.aspx"
      ]
    },
    {
      "id": "doctor-yellow-923-q5",
      "question": "Why might T4 photographs show two different builders’ plates?",
      "answer": "Check the car position first. JR Central identifies Hitachi as the builder of cars 1–3 and Nippon Sharyo for cars 4–7. All seven also carried JR Central’s own exterior plate. A photo of an ownership plate and a photo of a builder’s plate can therefore both be right for the very same car.",
      "evidence": [
        {
          "title": "ドクターイエロー（T4編成）部品オークション・車両解説",
          "url": "https://market.jr-central.co.jp/shop/pages/s983_t4auction.aspx",
          "publisher": "JR東海",
          "lang": "ja",
          "date": null,
          "page": null,
          "checked": "2026-11-07"
        }
      ],
      "sources": [
        "https://market.jr-central.co.jp/shop/pages/s983_t4auction.aspx"
      ]
    }
  ],
  "sources": [
    {
      "url": "https://jr-central.co.jp/news/release/_pdf/000043982.pdf",
      "checked": "2026-11-07",
      "lang": "ja"
    },
    {
      "url": "https://www.westjr.co.jp/press/article/2026/06/22/items/260622_00_press_500kei_dryellow.pdf",
      "checked": "2026-11-07",
      "lang": "ja"
    },
    {
      "title": "ドクターイエロー（T4編成）部品オークション・車両解説",
      "url": "https://market.jr-central.co.jp/shop/pages/s983_t4auction.aspx",
      "publisher": "JR東海",
      "lang": "ja",
      "date": null,
      "page": null,
      "checked": "2026-11-07"
    },
    {
      "title": "ドクターイエロー（Ｔ４編成）引退に伴うイベント等の実施について",
      "url": "https://jr-central.co.jp/news/release/_pdf/000043982.pdf",
      "publisher": "JR東海",
      "lang": "ja",
      "date": "2024-12-12",
      "page": 1,
      "checked": "2026-11-07"
    },
    {
      "title": "500系新幹線＆「ドクターイエロー」Ｔ５編成の引退について",
      "url": "https://www.westjr.co.jp/press/article/2026/06/22/items/260622_00_press_500kei_dryellow.pdf",
      "publisher": "JR西日本",
      "lang": "ja",
      "date": "2026-06-22",
      "page": 1,
      "checked": "2026-11-07"
    },
    {
      "title": "世界に誇る安全な新幹線を守ってきた「ドクターイエロー」の歩みを振り返る",
      "url": "https://www.tetsudo.com/report/481/",
      "publisher": "鉄道コム（栗原景）",
      "lang": "ja",
      "date": "2025-01-26",
      "page": null,
      "checked": "2026-11-07"
    }
  ],
  "detail": "Inspection train. A 700-series-derived broad bill.",
  "technical": {
    "record": [
      [
        "923 type · JR West T5",
        "923形 · JR西日本T5編成"
      ],
      [
        [
          "formation",
          "7 cars",
          "7両",
          "t5"
        ],
        [
          "base",
          "700 series",
          "700系",
          "t5"
        ],
        [
          "built",
          "2005",
          "2005",
          "t5"
        ],
        [
          "inspection_speed",
          "270 km/h",
          "270 km/h",
          "t5"
        ]
      ]
    ],
    "sources": {
      "zero": [
        "日本車輌製造",
        "0系新幹線の主要諸元",
        "https://www.n-sharyo.co.jp/museum/tec0/tec0-spec.html",
        null,
        "主要諸元・2両ユニット"
      ],
      "history": [
        "日本車輌製造",
        "新幹線の変遷",
        "https://www.n-sharyo.co.jp/business/tetsudo/shinkansen/tec-mechanism.html",
        null,
        "車体材質・台車・制御装置"
      ],
      "300": [
        "日本車輌製造",
        "300系新幹線",
        "https://www.n-sharyo.co.jp/business/tetsudo/pages/jrc300.htm",
        null,
        "交流電動機・アルミ車体"
      ],
      "500": [
        "日本車輌製造",
        "JR西日本500系新幹線",
        "https://www.n-sharyo.co.jp/business/tetsudo/pages/jrw500.htm",
        null,
        "先頭長15 m・アルミハニカム車体"
      ],
      "700": [
        "日本車輌製造",
        "JR東海700系新幹線",
        "https://www.n-sharyo.co.jp/business/tetsudo/pages/jrc700.htm",
        null,
        "アルミ中空形材・区間別速度"
      ],
      "hitachi": [
        "日立製作所",
        "新型高速新幹線電車",
        "https://www.hitachihyoron.com/jp/pdf/1997/02/1997_02_02.pdf",
        "1997-02",
        "表1・冊子154頁"
      ],
      "n700": [
        "JR東海",
        "N700系・N700A 車両のご案内",
        "https://railway.jr-central.co.jp/train/shinkansen/detail_01_01/index.html",
        null,
        "諸元"
      ],
      "n700early": [
        "日本車輌製造",
        "JR東海N700系新幹線",
        "https://www.n-sharyo.co.jp/business/tetsudo/pages/jrcn700.htm",
        null,
        "開発時の主要諸元"
      ],
      "n700s": [
        "JR東海",
        "N700S 車両のご案内",
        "https://railway.jr-central.co.jp/train/shinkansen/n700s/index.html",
        null,
        "諸元"
      ],
      "sic": [
        "JR東海",
        "N700Sに採用する新技術について",
        "https://jr-central.co.jp/news/release/_pdf/000035165.pdf",
        "2017-09-28",
        "SiC素子駆動システム"
      ],
      "battery": [
        "JR東海",
        "N700S量産車の仕様および投入計画",
        "https://jr-central.co.jp/news/release/_pdf/000039300.pdf",
        "2019-01-25",
        "別紙4・バッテリ自走"
      ],
      "t3": [
        "JR西日本・白山市",
        "トレインパーク白山でのドクターイエロー（T3編成）の車両展示",
        "https://www.westjr.co.jp/press/article/items/250130_00_DoctorYellowT3inHakusantrainpark.pdf",
        "2025-01-30",
        "1頁"
      ],
      "t5": [
        "JR西日本",
        "ワタシたちの解体新書 ドクターイエロー",
        "https://www.jr-odekake.net/navi/the_last_run/project-t5/",
        null,
        "T5編成 基本DATA"
      ],
      "alfa": [
        "JR東日本",
        "JR EAST Technical Review No.65",
        "https://www.jreast.co.jp/development/tech/pdf_65/tech-65-05-15.pdf",
        "2020",
        "冊子9頁・ALFA-X主要諸元"
      ]
    }
  },
  "engineering": {
    "record": {
      "scope": {
        "en": "923 inspection work; T5 identity and JR Central-group track-measurement account",
        "ja": "923形の検測・T5の情報とJR東海グループの軌道検測解説"
      },
      "facts": [
        {
          "label": {
            "en": "Electrical measurements",
            "ja": "電気関係の検測"
          },
          "value": {
            "en": "Overhead equipment, ATC signals and train-radio reception",
            "ja": "架線設備・ATC信号・列車無線受信状態"
          },
          "sources": [
            "west:west-t5"
          ]
        },
        {
          "label": {
            "en": "Track data processing",
            "ja": "軌道データ処理"
          },
          "value": {
            "en": "Underfloor sensors; real-time on-board waveform display",
            "ja": "床下センサー・車上でリアルタイム波形表示"
          },
          "sources": [
            "west:west-trackinspection"
          ]
        },
        {
          "label": {
            "en": "Maintenance handoff",
            "ja": "保線へのデータ受け渡し"
          },
          "value": {
            "en": "Urgent findings relayed immediately; routine data sent by that evening",
            "ja": "緊急情報は即時連絡・検測データは当日夕方に送信"
          },
          "sources": [
            "west:west-trackinspection"
          ]
        }
      ],
      "insights": [
        {
          "title": {
            "en": "A moving measurement laboratory",
            "ja": "走る測定室"
          },
          "text": {
            "en": "The purpose is to turn a high-speed run into maintenance decisions. Sensor readings are processed aboard, and track crews use the results to locate poor geometry and compare conditions before and after work.",
            "ja": "高速走行を保守判断につなぐ車両。センサー値を車上で処理し、保線側では線形の悪い箇所の把握や作業前後の状態確認に使う。"
          },
          "sources": [
            "west:west-trackinspection"
          ]
        }
      ],
      "gaps": [
        "This operational account does not establish sensor sampling rate, resolution or a common traction specification for T4 and T5."
      ]
    },
    "sources": {
      "west:west-t5": {
        "title": "ワタシたちの解体新書 ドクターイエロー",
        "publisher": "JR西日本",
        "url": "https://www.jr-odekake.net/navi/the_last_run/project-t5/",
        "date": null,
        "language": "ja",
        "locator": "T5 basic data and description of measurement targets",
        "checked": "2026-11-07"
      },
      "west:west-trackinspection": {
        "title": "ドクターイエロー｜線路の状態を診る",
        "publisher": "日本機械保線（JR東海グループ）",
        "url": "https://www.nkh-cjrg.co.jp/business/examine/dr-yellow/",
        "date": null,
        "language": "ja",
        "locator": "270km/hの高速走行で検測・ドクターイエロー検測室では",
        "checked": "2026-11-07"
      }
    },
    "checked": "2026-11-07"
  },
  "literature": []
}