{
  "timeline": [
    {
      "date": "1917/11",
      "category": "会社設立",
      "region": "",
      "importance": 3,
      "event": "三井物産造船部として宇野仮工場で創業",
      "detail": "",
      "significance": "三井造船の起源",
      "source": "有価証券報告書"
    },
    {
      "date": "1919/5",
      "category": "設備投資",
      "region": "",
      "importance": 2,
      "event": "玉工場（現玉野事業所）で操業開始",
      "detail": "",
      "significance": "主力造船拠点",
      "source": "有価証券報告書"
    },
    {
      "date": "1926/8",
      "category": "業務提携",
      "region": "欧州",
      "importance": 2,
      "event": "デンマークBurmeister & WainとB&W型舶用ディーゼル機関で技術提携",
      "detail": "現Everllence SE",
      "significance": "舶用エンジンの技術基盤",
      "source": "有価証券報告書"
    },
    {
      "date": "1937/7",
      "category": "会社設立",
      "region": "",
      "importance": 3,
      "event": "三井物産から分離独立し株式会社玉造船所を設立",
      "detail": "",
      "significance": "法人化・独立",
      "source": "有価証券報告書"
    },
    {
      "date": "1938/8",
      "category": "新規事業",
      "region": "",
      "importance": 2,
      "event": "化工機部門創設",
      "detail": "1940年4月化工機工場完成",
      "significance": "プラント事業の起点",
      "source": "有価証券報告書"
    },
    {
      "date": "1942/1",
      "category": "",
      "region": "",
      "importance": 1,
      "event": "三井造船株式会社に商号変更",
      "detail": "",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "1949/5",
      "category": "株式上場",
      "region": "",
      "importance": 3,
      "event": "東京及び大阪証券取引所に株式上場",
      "detail": "2013年1月大証廃止",
      "significance": "初の株式公開",
      "source": "有価証券報告書"
    },
    {
      "date": "1958/4",
      "category": "会社設立",
      "region": "",
      "importance": 1,
      "event": "三友不動産を設立",
      "detail": "2016年4月MESファシリティーズに改称",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "1960/11",
      "category": "会社設立",
      "region": "",
      "importance": 1,
      "event": "三井造船エンジニアリングを設立",
      "detail": "",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "1962/5",
      "category": "設備投資",
      "region": "",
      "importance": 3,
      "event": "千葉工場（現千葉事業所）操業開始",
      "detail": "",
      "significance": "造船能力拡大",
      "source": "有価証券報告書"
    },
    {
      "date": "1962/10",
      "category": "企業買収",
      "region": "",
      "importance": 2,
      "event": "日本開発機製造株式会社と合併",
      "detail": "資本金150百万円",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "1964/2",
      "category": "合弁設立",
      "region": "",
      "importance": 1,
      "event": "東海鋳造を子会社共同出資で設立",
      "detail": "1986年三井ミーハナイト・メタルに改称",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "1964/3",
      "category": "企業買収",
      "region": "",
      "importance": 1,
      "event": "四国ドックに経営参加",
      "detail": "",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "1965/10",
      "category": "設備投資",
      "region": "",
      "importance": 2,
      "event": "千葉造船所15万重量屯建造ドック完成",
      "detail": "",
      "significance": "大型船舶対応",
      "source": "有価証券報告書",
      "amount": "15万DWT"
    },
    {
      "date": "1967/2",
      "category": "IT投資",
      "region": "",
      "importance": 1,
      "event": "システム開発室設置",
      "detail": "1986年三井造船システム技研設立",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "1967/10",
      "category": "企業買収",
      "region": "",
      "importance": 3,
      "event": "株式会社藤永田造船所と合併",
      "detail": "資本金1",
      "significance": "",
      "source": "造船規模拡大",
      "amount": "949百万円"
    },
    {
      "date": "1968/6",
      "category": "設備投資",
      "region": "",
      "importance": 2,
      "event": "千葉造船所50万重量屯建造ドック完成",
      "detail": "",
      "significance": "VLCC建造能力獲得",
      "source": "有価証券報告書",
      "amount": "50万DWT"
    },
    {
      "date": "1973/3",
      "category": "合弁設立",
      "region": "",
      "importance": 1,
      "event": "三井物産共同出資で東洋鉄構を設立",
      "detail": "2017年4月吸収合併",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "1973/4",
      "category": "設備投資",
      "region": "",
      "importance": 2,
      "event": "由良工場操業開始",
      "detail": "",
      "significance": "中国地方の造船拠点",
      "source": "有価証券報告書"
    },
    {
      "date": "1974/2",
      "category": "会社設立",
      "region": "",
      "importance": 1,
      "event": "播磨工事を設立",
      "detail": "2018年4月三井E&S鉄構エンジニアリング",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "1974/4",
      "category": "企業買収",
      "region": "",
      "importance": 1,
      "event": "伊達製鋼に経営参加",
      "detail": "2003年4月吸収合併",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "1975/2",
      "category": "設備投資",
      "region": "",
      "importance": 2,
      "event": "玉野造船所海洋構造物建造ドック完成",
      "detail": "",
      "significance": "海洋事業基盤",
      "source": "有価証券報告書"
    },
    {
      "date": "1978/6",
      "category": "研究開発",
      "region": "",
      "importance": 1,
      "event": "昭島研究所開設",
      "detail": "1986年三井造船昭島研究所設立",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "1981/10",
      "category": "設備投資",
      "region": "",
      "importance": 2,
      "event": "大分事業所操業開始",
      "detail": "",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "1985/10",
      "category": "会社設立",
      "region": "",
      "importance": 1,
      "event": "三造環境サービス設立",
      "detail": "2018年4月三井E&S環境エンジニアリングに改称",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "1986/5",
      "category": "会社設立",
      "region": "",
      "importance": 1,
      "event": "三造メタル設立",
      "detail": "2006年三井ミーハナイト・メタルに吸収",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "1987/6",
      "category": "会社設立",
      "region": "",
      "importance": 1,
      "event": "三井造船プラント工事設立",
      "detail": "2018年4月三井E&Sプラントエンジニアリング",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "1988/10",
      "category": "組織再編|合弁設立",
      "region": "米州",
      "importance": 2,
      "event": "大分・由良両子会社化、三井物産と共同でPACECO CORP.設立",
      "detail": "2009年完全子会社化",
      "significance": "コンテナクレーン事業の起点",
      "source": "有価証券報告書"
    },
    {
      "date": "1988/12",
      "category": "企業買収",
      "region": "",
      "importance": 2,
      "event": "株式会社モデックに経営参加",
      "detail": "2003年三井海洋開発に改称",
      "significance": "海洋FPSO事業の起点",
      "source": "有価証券報告書"
    },
    {
      "date": "1989/12",
      "category": "企業買収",
      "region": "欧州",
      "importance": 2,
      "event": "Burmeister & Wain Scandinavian Contractor A/Sを買収",
      "detail": "",
      "significance": "プラント技術獲得",
      "source": "有価証券報告書"
    },
    {
      "date": "1990/4",
      "category": "会社設立",
      "region": "米州",
      "importance": 1,
      "event": "MES Engineering Inc.を設立",
      "detail": "2003年Engineers and Constructors International",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "1990/12",
      "category": "合弁設立",
      "region": "",
      "importance": 1,
      "event": "三幸実業出資で三幸物流を設立",
      "detail": "",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "1992/10",
      "category": "組織再編",
      "region": "",
      "importance": 1,
      "event": "三幸実業と合併",
      "detail": "資本金2",
      "significance": "",
      "source": "",
      "amount": "928百万円"
    },
    {
      "date": "1995/3",
      "category": "会社設立",
      "region": "",
      "importance": 1,
      "event": "エム・ディー特機を設立",
      "detail": "2018年三井E&Sパワーシステムズに改称",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "1995/9",
      "category": "企業買収",
      "region": "欧州",
      "importance": 2,
      "event": "英国Babcock Energy Limitedを買収",
      "detail": "Mitsui Babcock Energyに改称",
      "significance": "ボイラ事業欧州展開",
      "source": "有価証券報告書"
    },
    {
      "date": "2002/1",
      "category": "組織再編",
      "region": "",
      "importance": 1,
      "event": "三井造船鉄構工事が三造リフレ・運搬機エンジニアリング2社と合併",
      "detail": "",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "2003/4",
      "category": "事業売却",
      "region": "",
      "importance": 1,
      "event": "新潟造船が新潟鐵工所から造船事業を譲受",
      "detail": "",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "2004/4",
      "category": "企業買収|新規事業",
      "region": "",
      "importance": 2,
      "event": "三井鉱山から資源循環事業・水環境事業を譲受",
      "detail": "鹿島・三井物産と市原グリーン電力設立",
      "significance": "環境事業強化",
      "source": "有価証券報告書"
    },
    {
      "date": "2004/9",
      "category": "企業買収",
      "region": "",
      "importance": 1,
      "event": "ドーピー建設工業の株式取得し経営参加",
      "detail": "",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "2006/12",
      "category": "事業売却",
      "region": "欧州",
      "importance": 1,
      "event": "Mitsui Babcock Energy売却",
      "detail": "",
      "significance": "英国ボイラ事業撤退",
      "source": "有価証券報告書"
    },
    {
      "date": "2012/7",
      "category": "組織再編",
      "region": "",
      "importance": 1,
      "event": "鋼製橋梁事業・沿岸製品事業を三井造船鉄構エンジニアリングに移管",
      "detail": "",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "2014/3",
      "category": "企業買収",
      "region": "",
      "importance": 3,
      "event": "昭和飛行機工業を公開買付けで連結子会社化",
      "detail": "",
      "significance": "大型M&A",
      "source": "有価証券報告書"
    },
    {
      "date": "2015/10",
      "category": "企業買収",
      "region": "欧州",
      "importance": 2,
      "event": "TGE Marine AGを連結子会社化",
      "detail": "2016年10月MES Germanyと合併",
      "significance": "LNG関連欧州拠点",
      "source": "有価証券報告書"
    },
    {
      "date": "2017/3",
      "category": "企業買収",
      "region": "",
      "importance": 2,
      "event": "加地テックを公開買付けで連結子会社化",
      "detail": "",
      "significance": "圧縮機事業強化",
      "source": "有価証券報告書"
    },
    {
      "date": "2017/5",
      "category": "組織再編",
      "region": "",
      "importance": 3,
      "event": "持株会社体制への移行のため事業会社3社の準備会社を設立",
      "detail": "船舶艦艇・機械システム・エンジニアリング",
      "significance": "持株会社化への布石",
      "source": "有価証券報告書"
    },
    {
      "date": "2018/4",
      "category": "組織再編",
      "region": "",
      "importance": 3,
      "event": "持株会社体制に移行し商号を三井E&Sホールディングスに変更",
      "detail": "船舶艦艇・機械システム・エンジニアリングを各事業会社に承継",
      "significance": "グループ構造刷新",
      "source": "有価証券報告書"
    },
    {
      "date": "2019/12",
      "category": "事業売却",
      "region": "米州",
      "importance": 2,
      "event": "Engineers and Constructors International全株式売却",
      "detail": "",
      "significance": "米国EPC撤退",
      "source": "有価証券報告書"
    },
    {
      "date": "2020/3",
      "category": "事業売却",
      "region": "",
      "importance": 3,
      "event": "昭和飛行機工業全株売却・三井E&Sプラントエンジニアリング売却",
      "detail": "",
      "significance": "コア事業集中",
      "source": "有価証券報告書"
    },
    {
      "date": "2020/4",
      "category": "事業売却",
      "region": "",
      "importance": 1,
      "event": "市原グリーン電力全株式譲渡",
      "detail": "",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "2020/10",
      "category": "事業売却",
      "region": "",
      "importance": 2,
      "event": "三井E&S鉄構エンジニアリング株式70%を譲渡",
      "detail": "",
      "significance": "鉄構事業外出し",
      "source": "有価証券報告書"
    },
    {
      "date": "2021/3",
      "category": "事業撤退",
      "region": "",
      "importance": 3,
      "event": "千葉事業所での新造船事業を終了",
      "detail": "",
      "significance": "商船建造からの段階的撤退",
      "source": "有価証券報告書"
    },
    {
      "date": "2021/4",
      "category": "事業売却",
      "region": "",
      "importance": 1,
      "event": "三井E&S環境エンジニアリング全株譲渡",
      "detail": "",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "2021/10",
      "category": "事業売却|事業撤退",
      "region": "",
      "importance": 3,
      "event": "三井E&S造船株式49%を常石造船へ譲渡・艦艇事業を三菱重工へ譲渡し玉野事業所新造船終了",
      "detail": "",
      "significance": "造船からの本格撤退",
      "source": "有価証券報告書",
      "amount": "49%"
    },
    {
      "date": "2022/1",
      "category": "事業売却",
      "region": "",
      "importance": 1,
      "event": "四国ドック全株式譲渡",
      "detail": "",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "2022/4",
      "category": "事業売却",
      "region": "",
      "importance": 1,
      "event": "MESファシリティーズ全株式譲渡",
      "detail": "",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "2022/4",
      "category": "株主対応",
      "region": "",
      "importance": 2,
      "event": "東京証券取引所プライム市場に移行",
      "detail": "",
      "significance": "市場区分再編対応",
      "source": "有価証券報告書"
    },
    {
      "date": "2022/10",
      "category": "事業売却",
      "region": "",
      "importance": 2,
      "event": "三井E&S造船株式17%を追加譲渡し関連会社化",
      "detail": "",
      "significance": "持分法適用会社化",
      "source": "有価証券報告書",
      "amount": "17%"
    },
    {
      "date": "2023/4",
      "category": "組織再編",
      "region": "",
      "importance": 3,
      "event": "三井E&Sマシナリー・三井E&Sビジネスサービスを吸収合併し商号を三井E&Sに変更",
      "detail": "",
      "significance": "グループ再構築",
      "source": "有価証券報告書"
    },
    {
      "date": "2023/4",
      "category": "企業買収|新規事業",
      "region": "",
      "importance": 3,
      "event": "IHI原動機の舶用大型エンジン事業を承継した新会社を取得",
      "detail": "三井E&S DUに改称",
      "significance": "舶用エンジン事業強化",
      "source": "有価証券報告書"
    },
    {
      "date": "2023/6",
      "category": "ガバナンス改革",
      "region": "",
      "importance": 2,
      "event": "監査役会設置会社から監査等委員会設置会社に移行",
      "detail": "",
      "significance": "ガバナンス体制刷新",
      "source": "有価証券報告書"
    },
    {
      "date": "2024/4",
      "category": "事業売却",
      "region": "",
      "importance": 1,
      "event": "三井造船昭島研究所全株式を三井E&S造船へ譲渡",
      "detail": "",
      "significance": "",
      "source": "有価証券報告書"
    },
    {
      "date": "2024/6",
      "category": "事業売却",
      "region": "",
      "importance": 2,
      "event": "三井海洋開発株式の一部を売出しの方法により売却",
      "detail": "",
      "significance": "持株比率引下げ",
      "source": "有価証券報告書"
    },
    {
      "date": "2025/4",
      "category": "事業売却",
      "region": "",
      "importance": 2,
      "event": "常石造船と三井E&S造船の株式譲渡合意書を締結",
      "detail": "",
      "significance": "造船事業完全撤退の布石",
      "source": "有価証券報告書"
    }
  ]
}