I G Tennant Company During World War Two

GH Tennant Company During World War Two
Minneapolis, MN

1870 – Present
1870-1969 as GH Tennant Company
1969-Present as Tennant Company

This page added 2-28-2025.

George Tennant began his lumber mill business on St. Anthony Falls in Minneapolis in 1870. By the mid-1880s, he owned several lumber mills and began to specialize in hardwood flooring. By the late 1920s, when the Great Depression hit, the forests of the Midwest were depleted. So, in 1932, Tennant’s company began producing motorized floor cleaning equipment that could clean all the wood flooring it had been installing over the past 40 some years. The Models K and V were introduced in the early 1940s. The Model K was the lone machine the US Military allowed Tennant to build. as the rest were decoded due to wartime shortages. However, Tennant received several contracts in 1942 to make gun sights and other miscellaneous parts for both the U.S. Army Ordnance and the U.S. Navy.

GH Tennant became Tennant Company in 1969 upon going public. In 2018, Tennant Company had sales of $1.12 billion and had approximately 4,300 employees. As of May 2023, the Tennant Company is the world's largest manufacturer of autonomous mobile robots with over 6,000 units deployed across the world.

This is the machine shop at GH Tennant Company at the beginning of World War Two. Note that the floor consists of a well polished and maintained hard maple. This is very unusual as tool room floors of the era were normally constructed of concrete or wooden blocks. However, Tennant chose the maple for its floor as it manufactured the equipment to keep it well polished. It was a company that used its own products. Image courtesy of Tennant Company.

This was the company's product line at the onset of World War Two. The National Production Board allowed the company to continue to manufacture the Model K during the war. Like many other companies during World War Two, the GH Tennant Company made a product to help win the war that was unlike its normal civilian product line. Image courtesy of Tennant Company.

G H Tennant Company World War Two Products: Table 1 shows that the company had two major contracts totaling $445,000. Both contracts were for sighting systems that were purchased by Army Ordnance. Contract 271-ORD-2741 was for M7 sighing telescopes that were used on M1 37mm anti-aircraft guns on M3 gun carriages and M15 half-tracks.

Table 1 - GH Tennant Company's Major World War Two Contracts The information below comes from the "Alphabetical Listing of Major War Supply Contracts, June 1940 through September 1945." This was published by the Civilian Production Administration, Industrial Statistics Division, Requirements and Progress Branch January 21, 1946.
Product - Customer	Contract Number	Contract Amount	Award Date	Completion Date
Sighting Systems - Army Ordnance	271-ORD-2741	$347,000	11-1942	10-1943
Sighting Systems - Army Ordnance	271-ORD-4441	$98,000	4-1945	10-1945
Total		$445,000

The term "sighting system" noted in the contracts is rather generic and does not identify the piece of equipment purchased. This post-war thank you letter from Army Ordnance indicates the company produced the M7 telescope. Image courtesy of Tennant Company.

This is part of a several page document the GH Tennant Company completed after World War Two at the request of the National Military Establish Munitions Board. This document confirms that the company manufactured M7 gun sights. It also made torpedo parts. Image courtesy of Tennant Company.

The next four photos show the M7 telescope. They came in boxes of two units each.

The M7 sighting telescope is nine inches long.

This newspaper article dated 10-1-1943 is confusing. While the article provides important information that the company employed 100 persons during World War Two, the gun sight shown is not an M7. While the completion date of contract 271-ORD-2741 matches the timeframe of the article, the next major contract the company was awarded, 271-ORD-4441, was not released until April 1945. This implies the second contract referenced in the article was for less than $50,000 and not a major contact. Image courtesy of Tennant Company.

Below are several pages for TM-9 235 37-mm AA Gun Materiel. These pages show the M7 telescope and how it was mounted on the M3 gun carriages series.

This page shows that the proper term for the device is Telescope M7. It was a one magnification power unit.

There were two M7s used on the weapon by two different crew members. One was used for azimuth and the other for elevation.

This M3 37mm gun carriage the is weapon on which the GH Tennant-built M7 telescopes were used. The M3 gun system also mounted two .50 caliber machine guns. This example is on display at the Indiana Military Museum in Vincennes, IN. Author's photo.

This very rare restoration does not have the M2 sighting system on it. Therefore, it does not have the M7 telescopes mounted. Author's photo.

The M3 37mm gun carriage with GH Tennant-built M7 was used for anti-aircraft defense by the U.S. Army during the Solomon's campaign in the South Pacific. As the US military advanced up the island chain and occupied yet another island, the M3 anti-aircraft guns were one of the first weapons deployed once the landing beaches were secure. Author's photo.

This pre-World War Two photo shows the two M7 telescopes mounted on the gun carriage.

This M15 half-track with a 37mm and twin coaxial .50 machine guns is on display at the National Museum of Military Vehicles in Dubois, WY. This mobile weapon was first used in the Allied invasion of North Africa in November 1942. It was further used in Sicily, Italy, and in northeast Europe. It was also used in the Pacific in the Philippines and on Okinawa. Author's photo.

This enlargement shows the GH Tennant-built M7 telescope used for azimuth sighting. Each U.S. Army anti-aircraft company was equipped with eight M15 half-tracks. Each company also had eight M16 half-tracks mounting a 40mm Bofors anti-aircraft gun. Author's photo.

This photo is a further enlargement of the M7 telescope.

Autocar was the only manufacturer of the M15 half-track. It produced a total of 600 M15s and 1,652 M15As. What is really cool about the Autocar advertisement is that the artist went into enough detail to show the two M7 telescopes.

This photo shows an M15 guarding the Normandy beach. The azimuth M7 telescope is visible in the photo.

This posed photo of an M15 shows the elevation M7 telescope at Normandy.

The view is a Mark XIII aerial torpedo. The Mark XIII was also used by PT boats but would not have the ring around the propellers. International Harvester produced the Mark XIII along with Pontiac Motor Division of General Motors, Pontiac, MI, the Naval Torpedo Station at Newport, RI, and Amertorp Corporation, Forrest Park, IL. Author's photo from the National Museum of the United States Air Force in Riverside, OH.

This was one of the most complicated and difficult weapons of World War Two to build, containing 5,222 individual parts and 1,225 assemblies. GH Tennant could have made any of these parts under sub-contract from one of the torpedo manufacturers. Author's photo.

This is one of many advertisements that the company produced during the war years. It notes that it is an ordnance manufacturer making gun sights. Image courtesy of Tennant Company.

The GH Tennant Company World War Two Plant: The company moved into 2550 North Second Street, Minneapolis, MN in 1940 and stayed here until 1957.

This post-World Two photo shows the plant from the intersection of North Second Street and North 26th Avenue. Image courtesy of Tennant Company.

This appears to be the same view of the plant taken in an early 1950s photo, the only difference being the vintage of the vehicles parked out front. Image courtesy of Tennant Company.

Here is a Google Maps street view from the same vantage point.

This Google Earth view shows the original plant on the corner with at least five additional buildings that were added as production expanded.