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Company · 1951–2026

Seventy-five years of TriOptimum

Three engineers, one workshop and a pressure gauge that had to be right the first time. This is how a Halsworth instrument maker became one of the world’s most diversified technology companies.

MILL LANE WORKSHOP 1951 · PLAN Reconstructed floor plan of the rented workshop on Mill Lane, Halsworth, where TriOptimum was founded in 1951: a single room about twelve by seven metres with a door to the lane, three windows, a long workbench, a lathe, a calibration bench with the dead-weight tester, stores shelving, a coke stove, and three desks in the corner for the founders. 112233445566AABBCCDD APEMSO123456712 0007 200MILL LANEKEY1 WORKBENCH WITH VICES2 CALIBRATION BENCH AND DEAD-WEIGHT TESTER3 LATHE4 STORES5 COKE STOVE6 DESKS: A. PELLOW, E. MARCHBANK, S. OSTROWSKI7 DOOR TO MILL LANERECONSTRUCTED FROM THE 1951LEASE PLAN AND PHOTOGRAPHSIN THE CORPORATE ARCHIVE. TITLE MILL LANE WORKSHOP 1951 · PLAN DWG NO. TRI-75-0014 SCALE 1:50 REV A DRN / CHK ARCH-DO / TRL-DO DATE 2026-03-09 SHEET 1 OF 1
The founders’ workshop on Mill Lane, Halsworth, as it was in 1951. Drawing TRI-75-0014, reconstructed by the Corporate Archive for the anniversary.

  1. 1951

    A workshop on Mill Lane

    Arthur Pellow, Edith Marchbank and Samuel Ostrowski found the Tri-Optimum Instrument Company in a rented workshop in Halsworth. The name records the three things they promised every customer: accuracy, durability and economy. Their first product, the Model 1 pressure gauge, is calibrated by hand and sold to dairies, breweries and the local gasworks.

  2. 1956

    First exports

    A contract for 2,400 gauges for the pumping stations of three Dutch water boards takes the company abroad for the first time. Edith Marchbank travels to Rotterdam to sign it and returns with orders for a further 900.

  3. 1962

    Into the ground

    Tri-Optimum acquires the Westralian Drill and Cutting Company of Perth, its first business outside instruments and the origin of today’s Resources & Materials division.

  4. 1964

    TriOptimum Corporation

    The company drops the hyphen and the word “Instrument”, reorganizes as TriOptimum Corporation and moves into its first purpose-built offices at Halsworth Park.

  5. 1967

    New York

    TriOptimum lists its shares on the New York Stock Exchange and reincorporates in Delaware, keeping its headquarters in Halsworth. It has paid a dividend every year since.

  6. 1968

    The RC-12

    The RC-12 relay cabinet brings automatic control to factories, ports and power stations. More than 58,000 are built over twenty years; some are still in service.

  7. 1972

    Security Products

    TriOptimum Security Products is formed to make vault doors for banks and, soon after, the first electronic door controllers for laboratories and government buildings.

  8. 1979

    Research Laboratories

    TriOptimum Research Laboratories opens at Halsworth Park with 140 scientists and engineers and a mandate to work ten years ahead of the divisions.

  9. 1984

    Medical Systems

    The acquisition of Van Roon Medische Techniek of Leiden establishes TriOptimum Medical Systems, beginning with patient monitoring and intensive-care beds.

  10. 1989

    Orbital & Research Systems

    TriOptimum forms Orbital & Research Systems to build structures and life-support equipment for crewed research in orbit.

  11. 1993

    AccessNet 4K

    The AccessNet 4K wall keypad goes on sale. It guards the doors of several hundred research buildings and begins the AccessNet line that Security Products still sells today.

  12. 1995

    The archive opens its doors

    The TriOptimum Corporate Archive becomes the first company archive to deposit its retired products with Lazarus, the digital preservation archive now run by Frothly. The first deposit is the firmware of the AccessNet 4K.

  13. 1998

    Network Services

    TriOptimum Network Services is founded in Toronto to run the company’s own networks, and takes its first outside customer, a hospital group, the following spring.

  14. 2003

    Citadel Station

    Citadel Station, an orbital research and mining platform built and operated by TriOptimum, enters service.

  15. 2004

    A licensed operator

    TriOptimum receives its first Turing Registry license, for the mining laser at Citadel Station, and becomes one of the first industrial companies to license an autonomous system voluntarily.

  16. 2007

    Agrisystems

    TriOptimum Agrisystems is established in Wageningen to commercialize the closed-environment growing systems developed for Citadel Station.

  17. 2019

    Citadel modernized

    A four-year modernization of Citadel Station is completed, including new hydroponic groves, regeneration bays and a licensed station-management system. In Toronto, Network Services begins hosting a relay for the Glossia messaging network.

  18. 2021

    Arden

    Medical Systems introduces the Arden regenerative care bay, which is now approved for clinical use in 31 countries.

  19. 2022

    The Von Braun

    The long-range research vessel Von Braun enters service. Its propulsion system was designed by an Orbital & Research Systems team led by Dr. Marie Delacroix, who left the company in 2023.

  20. 2025

    Toronto North

    Network Services opens Toronto North, a 64 MW data center and the largest single investment in the company’s history outside orbit.

  21. 2026

    Seventy-five years

    TriOptimum celebrates its seventy-fifth anniversary with 118,400 employees in 47 countries and an open day at Halsworth Park attended by 11,600 people.

Compiled by the TriOptimum Corporate Archive. Researchers may consult the archive’s collections by appointment: see Corporate Archive.