With the outbreak WWI the Commer Factory factory turned its attention to the manufacture of military vehicles for the British Army producing over 3000 vehicles by the time the war ended. Commer struggled in post war Britain and in 1926, having gone into receivership several times, was acquired by the Humber group which can be dated back to 1868 when the company’s founder, Thomas Humber, operated a bicycle factory. In 1931, Humber in turn was taken over by the Rootes Group.
The Rootes Group had been founded by William Rootes (later Sir William) in Kent but had moved to moved to Maidstone prior to WWI. During this war Rootes repaired and rebuilt aeroplane engines. By 1924 Rootes were the largest car and truck distributor in the United Kingdom having acquired many other companies including Hillman, Hummer, Talbot, Sunbeam, Minx Alpine and Karrier Hillman was intended to be the basic brand, Singer slightly more upmarket, Sunbeam the sports brand and Humber the luxury models. Commer and Karrier were the commercial vehicle brands, with Commer initially manufacturing light vans and the Karrier badge appearing on heavy vans and light duty trucks. Karrier can be traced back to Clayton and Company, a 1904 company that started making Karrier cars. In 1920 changed the company name to Karrier Motors Ltd Commer acquired Karrier as part of Rootes acquisition of Karrier in 1934. As uncanny as the Rootes group was for picking winners they had a lapse in judgement when visiting Germany’s Volkswagon plant and determined the beetle would have little success as a small car.
Commer, like all other British manufacturers made a full range of military vehicles for the war effort. Some models were still in use by the British Forces up until 1980. British comedian Frank Muir who served in the British Army is reported to have commented famously “The Commer has come to a full stop” when reporting a Commer truck broken down on the roadside.
The Superpoise range was introduced in 1939 and had semi-forward and full-forward control options. They were 1½ to 6 tons with either a 6 cylinder petrol or Perkins diesel engine. A new Superpoise range was introduced in 1955 with 2 ton to 5 ton payloads.
In the late 1950s and 60s, some Karrier vehicles were fitted with the iconic Rootes TS3 two-stroke opposed piston diesel engine as fitted in Commers commercial trucks. During the 1970s the Rootes Group was taken over by Chrysler Europe and the Commer name was replaced by Dodge. Peugeot then purchased Chrysler Europe in 1978 and the Commer factory was run in partnership with Renault’s truck division. It continued to produce the Dodge commercial truck range fotr a while but eventually they ceased production and mainstream Renault trucks and buses went into full-time production in the early 1990s.
Many Commer vans and trucks are noted for being fitted with the Rootes TS3 engine, a two-stroke diesel three-cylinder horizontally-opposed piston engine which came to be known as the ‘Commer Knocker’ due to the unique knocking sound it produced. Later Commer vehicles came with Perkins and Cummins diesel engines, and less commonly Mercedes diesel engines.
Commer produced the Commando bus just after WW2, and the Avenger on 28 February 1948, deploying the TS3 engine in the Avenger in 1954.
Commer became known in later years as a maker of vans for the British Post Office, in particular the Commer FC which was introduced in 1960 with an assortment of body styles. After both engine and interior upgrades it was renamed the PB in 1967 and the SpaceVan in 1974 afterwhich it was then sold as Dodge or Fargo until 1976. Commer and Fargo names were dropped from the range the same year.
The Commer TS3 diesel engine was specifically designed by the Rootes group for use in Commer trucks during the 1950s and 1960s. It had started its development with Tilling-Stevens who had based it’s design on a Sulzer Brothers concept. It didn’t however become a reality until it went into production with the Rootes Group when they bought out Tilling-Stevens in 1950 (hence the TS in the name). Tilling Stevens had been a builder of petrol electric transmissions and automobiles. Sulzer is a Swiss mechanical engineering firm with its beginnings in 1775. Rudolf Diesel worked for them in the 1890s and Sulzer built its first engine in 1898. Today Sulzer is a publicly traded company with international subsidiaries with its shares listed on the Swiss Stock Exchange.
Released in 1954 the two stroke compression – ignition TS3 was the first diesel engine used by Rootes Group and operated quite differently from other diesel engines of the day. The 3.25 litre engine developed 90hp which was equivalent to contemporary four-stroke diesel engines of more than twice that capacity. The engine was used in industrial applications as well as in Commer commercial vehicles. Production of the TS3 ceased in 1968 after the Chrysler acquisition.
It was unusual in being an opposed piston engine, an engine where each horizontal cylinder contains two pistons, one at each end, that move in opposition to each other. Both sets of pistons drive a single crankshaft whereas most opposed piston engines have a separate crankshaft at each end of the cylinder. The TS3 engine used a single crankshaft beneath the cylinders, each piston driving it through a connecting rod, a rocker bellcrank and a second connecting rod. The crankshaft had six crankpins and there were six rockers. The engines gained a reputation for good performance but the quill shaft was somewhat prone to breaking if over-worked. As the horizontal cylinders were lower than a vertical engine, the engine was mounted beneath the floor of the cab and the need for a bonnet or hood was removed.
The 3.25 litre engine developed 90 hp (67 kW), equivalent to contemporary 4-stroke diesel engines of more than twice the capacity.
The legendary Commer is one of the unsung heroes of the Australian road transport industry. It was such a common sight on Australian roads it was hardly given a thought, that is, if it were not for the famous knocking sound that made it stand out from the rest. The distinct knocking sound that could be heard for miles giving the truck its famous ‘Knocker’ nickname. The first Commer in Australia were not very successful and even the refined version released in 1953 caused problems for operators. The highways at the time were little more than narrow winding bush tracks and the Commer was renowned for its habit of de-coking, or melting its pistons as it struggled to complete the task at hand.
Drivers of Commers had to have a fairly extensive mechanical background to keep them going. However, many old timers today tip their hat to the Commer Knocker. Its’ work in the Australian outback was more arduous than the Commer had been built for. The more conventional diesel Perkins engine eventually replaced the Commer engine as the preferred option for power. Some operators, such as Norm Elliott of Benalla, Victoria, fitted a V8 Perkins with a V-belt bogie drive. This allowed for a bigger payload and maximum use of the extra power. The demise of the Commer Knocker in the 1970s marked the end of an era in Australia’s road transport history.