Private company

Hartford Steam Boiler Inspection and Insurance Company

Logo: The Hartford Steam Boiler Inspection and Insurance Company, CC BY-SA 4.0, via Wikimedia Commons4

Global specialty insurer and reinsurer

The Hartford Steam Boiler Inspection and Insurance Company (HSB) is a global specialty insurer and reinsurer headquartered in Hartford, Connecticut. It was founded in 1866 and is the largest provider of equipment breakdown insurance and related inspection services in North America serving over five million commercial locations.2 Wikipedia text CC BY-SA 4.0

Last updated Oct 21, 2026.

Overview

1866Founded1
  • Industryinsurance1
  • HeadquartersHartford, United States1
  • Websitewww.hsb.com/HSBGroup
  • Legal formInsurance Company3
  • LEI549300DQPMR2TQKNLE683
  • StatusActive3
  • LEI statusIssued and current3
  • Registered addressONE STATE STREET, 06102 Hartford, United States3
  • Registered withNational Association of Insurance Commissioners, 114523

The Hartford Steam Boiler Inspection and Insurance Company (HSB) is a global specialty insurer and reinsurer headquartered in Hartford, Connecticut. It was founded in 1866 and is the largest provider of equipment breakdown insurance and related inspection services in North America serving over five million commercial locations.2

Corporate structure

Hartford Steam Boiler Inspection and Insurance Company is part of a group headed by Munich Re. 371 entities, 36 countries on record. Switch between the flow chart and the network, and select any entity to see its details.

  • Munich Re München, Germany
    • Ergo 100% · Düsseldorf, Germany
      • DKV Subsidiary · Cologne, Germany
      • D.A.S. LUXEMBURG ALLGEMEINE RECHTSSCHUTZ-VERSICHERUNG S.A. Subsidiary · Strassen, Luxembourg
      • Ergo Hestia Subsidiary · Poland, Poland
      • ERGO Life S.A. Subsidiary · Grevenmacher, Luxembourg
      • Ergo Versicherung Subsidiary · Germany
    • ERV Evropská pojišťovna 100% · Praha 8, Czechia
      • Etics ITP Subsidiary · Czechia
    • DKV Belgium Brussel, Belgium
    • ERGO International Aktiengesellschaft Düsseldorf, Germany
      • ERGO Insurance SE Tallinn, Estonia
      • Akcine draudimo bendrove "Gjensidige" Subsidiary · 100% · Vilnius, Lithuania
    • Ergo Lebensversicherung Hamburg, Germany
    • ERGO Vorsorge Lebensversicherung Düsseldorf, Germany
    • Europaeiske Rejseforsikring København, Denmark
    • Forst Ebnath Ebnath, Germany
    • Great Lakes Insurance München, Germany
    • Hartford Steam Boiler Inspection and Insurance Company Hartford, Connecticut, United States
    • MUNICH-AMERICAN HOLDING CORPORATION Wilmington, Delaware, United States
      • American Family Home Insurance Company Subsidiary · Amelia, Ohio, United States
      • AMERICAN MODERN HOME INSURANCE COMPANY Subsidiary · Amelia, Ohio, United States
      • AMERICAN MODERN INSURANCE COMPANY OF FLORIDA, INC. Subsidiary · Amelia, Ohio, United States
      • AMERICAN MODERN LLOYD'S INSURANCE COMPANY Subsidiary · Amelia, Ohio, United States
      • AMERICAN MODERN PROPERTY AND CASUALTY INSURANCE COMPANY Subsidiary · Amelia, Ohio, United States
      • AMERICAN MODERN SELECT INSURANCE COMPANY Subsidiary · Amelia, Ohio, United States
      • AMERICAN SOUTHERN HOME INSURANCE COMPANY Subsidiary · Amelia, Ohio, United States
      • BRIDGEWAY INSURANCE COMPANY Subsidiary · Princeton, New Jersey, United States
      • MIDLAND-GUARDIAN CO. Subsidiary · Batavia, Ohio, United States
      • MIDWEST ENTERPRISES INC Subsidiary · Amelia, Ohio, United States
      • MUNICH AMERICAN REASSURANCE COMPANY Subsidiary · Atlanta, Georgia, United States
        • MUNICH AMERICAN LIFE REINSURANCE COMPANY Subsidiary · Atlanta, Georgia, United States
        • MUNICH AMERICAN REASSURANCE COMPANY PAC, INC Subsidiary · Atlanta, Georgia, United States
      • MUNICH RE CVC INVESTMENT CORP. Subsidiary · Dover, Delaware, United States
      • MUNICH RE DIGITAL PARTNERS US HOLDING CORPORATION Subsidiary · Dover, Delaware, United States
      • MUNICH RE WEATHER & COMMODITY RISK HOLDING INC. Subsidiary · The Woodlands, Texas, United States
        • MUNICH RE ENERGY TRANSITION FINANCE INC. Subsidiary · Dover, Delaware, United States
        • MUNICH RE TRADING LLC Subsidiary · The Woodlands, Texas, United States
      • SPECIALTY INSURANCE SERVICES CORPORATION Subsidiary · Amelia, Ohio, United States
      • THE ATLAS INSURANCE AGENCY, INC. Subsidiary · Amelia, Ohio, United States
      • THE MIDLAND COMPANY Subsidiary · Amelia, Ohio, United States
    • American Modern Insurance Group, Inc. Subsidiary · Amelia, Ohio, United States
    • MEAG Subsidiary · Munich
    • Munich Reinsurance America Subsidiary
    • MUNICH HOLDINGS OF AUSTRALASIA PTY LTD Subsidiary · 100% · Sydney, Australia
      • CORION PTY LIMITED Subsidiary · 100% · Sydney, Australia
      • MUNICH REINSURANCE COMPANY OF AUSTRALASIA LIMITED Subsidiary · 100% · Sydney, Australia
    • PONGA SILVA LIMITED Subsidiary · 100% · Rotorua, New Zealand
    • "HESTIA LOSS CONTROL" SPOLKA Z OGRANICZONA ODPOWIEDZIALNOSCIA Subsidiary · Sopot, Poland
    • 13TH & F ASSOCIATES L.P. Subsidiary · Houston, Texas, United States
    • 1880fwd GmbH Subsidiary · München, Germany
    • ADVIA Subsidiary · Antwerpen, Belgium
    • AKCIONERNOE OBSESTVO "UNITI STRAHOVANIE" (АКЦИОНЕРНОЕ ОБЩЕСТВО "ЮНИТИ СТРАХОВАНИЕ") Subsidiary · Moskau, Russia
    • ALLYSCA Assistance GmbH Subsidiary · München, Germany
    • AMERICAN ALTERNATIVE INSURANCE CORPORATION Subsidiary · Princeton, New Jersey, United States
    • Battery Park Holding GmbH Subsidiary · München, Germany
    • BELL & CLEMENTS (LONDON) LIMITED Subsidiary · London, United Kingdom
    • and 197 more

Built from parent and subsidiary links from GLEIF, the Global Legal Entity Identifier Foundation (CC0); subsidiaries, stakes and holdings from Wikidata (CC0). Each entity in the chart links to its source.

The story

The Hartford Steam Boiler Inspection and Insurance Company was founded on June 30, 1866. The company was conceived at a time when catastrophic boiler explosions were common events, occurring about once every four days.

Steam Power and the Industrial Revolution

Up until the 1850s in the United States, a great deal of manufacturing was carried on by small plants located in rural areas. Water from streams and rivers was the source of power for equipment. However, water power had reached the limits of its industrial capacity. Manufacturers turned to steam boilers and engines. The industrial revolution was underway.

The advent of steam power created a new industrial hazard – disastrous boiler explosions. These tragedies occurred with increasing frequency with loss of life and property. Though the potential of steam power seemed infinite, controlling the power and safely harnessing it was crudely developed. As applications for steam power became more complex, the dangers became more acute.

In the fall of 1857, a group of young men interested in science and mechanics formed the Polytechnic Club of Hartford. Its original members were E.K. Root (Colt Foreman), E.M. Reed, H. Lord, C.B. Richards, C.F Howard, J.M. Allen, F.A. Pratt, A. Whitney, J.L. Blanchard, and J.A. Ayres. They discussed articles on Science and Mechanics. They proposed the "Guaranteed Steam Boiler Inspection," and with it, offered a guarantee against loss and property damage. The club was disbanded because of the Civil War and lack of interest. The idea was resurrected in 1866 under the direction of R.W. Jarvis (Colt Manager), C.M. Beach, G. Crompton, and H.H. Hayden Esq. The State of Connecticut granted a charter for Corporation in May 1866, and the Corporation was organized in November 1866 with E.C. Roberts as its first president. Soon after, Roberts stepped down, and J.M. Allen became its second president.

In 1919, the Hartford Steam Boiler Insurance and Inspection Company got tired of paying the claims on all those broken boilers, so they came up with the idea of this special piping configuration and mandated it for anyone who wanted insurance on their steam boiler. Before long, everyone was calling it the Hartford (or Underwriters) Loop. The Loop had a very positive impact on the industry, according to the records of boiler failures before and after 1919.

Polytechnic Club Addresses Issue of Boiler Explosions

During this time, a group of industrialists and business leaders in Hartford, Connecticut, formed a group to discuss technical and scientific issues of the day. This group, the Polytechnic Club, included Francis A. Pratt and Amos Whitney the founders of the Pratt & Whitney, and Elisha Root, president of Colt’s Patent Firearms Manufacturing Co., among others.

One of the founders of the Polytechnic Club was Jeremiah M. Allen, who would become president of The Hartford Steam Boiler Inspection and Insurance Company and the principal American figure to develop and apply the principle of combining boiler inspections with insurance.

From Wikipedia’s article on Hartford Steam Boiler Inspection and Insurance Company, shared under CC BY-SA 4.0.5

Subsidiaries and ownership

Parent company (GLEIF)

Ownership links from GLEIF, the Global Legal Entity Identifier Foundation (CC0); each one cites its LEI record.

Timeline

  1. Apr 11, 2018Parent Directly consolidated by Munich Re3
  2. 1866Founded Founded1