1940s BMB Brockhouse Tractor. Austin 7 Chassis; BSA 320cc Engine

1940s BMB Brockhouse Tractor

Austin Seven Chassis

Serial No 5357A

BSA 320cc  ‘Model A’ Engine

Engine no A 1734

Rope Pull-start

Reputed WW2 Use

This attractive little tractor was manufactured in the 1940s. It was reputedly used during WW2 as an aircraft carrier tug. Given Brockhouse military contracts, this may be true, or possibly it was the intention behind its construction – many similar projects were launched during WW2 – but I have no proof of it.

The British Motor Boat Co changed their name to BMB Engineering around 1940. They made the ‘Cultmate’ as a lightweight tractor.

There was obviously a demand during the War for tractors, as there was for all utility vehicles. Old Austin Sevens were plentiful at this time, and this unique vehicle was designed by BMB and assembled by Brockhouse using a shortened Austin Seven chassis with a tractor rear end and diff and a BMB Cultmate body. It retains the regular Cultmate engine, a 320cc BSA Model A industrial motor, for its powerplant. The serial number on the BMB Brockhouse chassis plate is 5357A.

BMB and Brockhouse did not manufacture the full size President tractor until 1947, so it’s also possible they built it – using available parts – to assess the market for the subsequent full-size Morris 8 powered President (with a larger chassis). One thing is certain – it was professionally designed and its construction is first class.

Brockhouse, of course, had military contracts during the War, manufacturing the Wellbike and, postwar, the Corgi scooter.

Although I have no experience of tractors, I’ve previously owned a few Brockhouse Corgis and an Austin Seven, as well as many BSA motorcycles and bicycles. So the curious combination of Austin, Brockhouse and BSA in one vehicle appealed to me. Also, look at the photo below. From the rear it’s undoubtedly a tractor …but from the front, with no mudguards to spoil the view of its transverse-leaf front suspension and a front grille reminiscent of a 1920s American jalopy, it looks like a small hotrod 🙂

The chassis is solid. There’s no rust anywhere. Everything works well. The BMB starts easily, using a rope to turn its engine pulley. I had it serviced by Everest Motorcycles, who also fitted an engine cut-out and a top-mounted motorcycle silencer that screws into the exhaust manifold. In the video below, you can see me collecting the tractor from Terry at Everest Motorcycles, and driving it for the first time.






Engine no A 1734




BMB tractors were manufactured by the Brockhouse Company of Southport. the initials BMB stood for British Motor Boats, who designed the tractor. BMB started by building a range of small garden tractors and ‘Iron Horse’ type walk-behind units for pulling market gardener’s cultivation equipment. The President, made from 1947 to 1956, was built as an affordable machine using post war surplus production capacity, to help with the cultivation of small areas during postwar rationing.

The smallest BMB tractor was the 1 3/4hp Hoemate, illustrated below.

 The 3hp Cultmate was the medium range unit. You can see an example below: some had only the two driving wheels, while the one illustrated is fitted with a seat and rear wheels.

The largest unit, the Plowmate (below), used  a 6hp JAP engine.

The President, made later, was a full-size tractor with a 918cc Morris 8 engine (below).

This BMB Brockhouse was not the only tractor to use an Austin chassis. Austin themselves made tractors, from 1919, although their diversification into agricultural machines ended in the early thirties:



These days, we leave the house, get in the  car, put on the seatbelt, turn the key, start the car with little effort, and drive to wherever we need to go. Most of the country has roads where you can drive at 70mph.

In the 1930s, 6 volt batteries did not hold their charge very well, and the starting handle was the regular way to start a car. Great Britain was the world’s leading industrialized nation, and car prices had come down to affordable levels, so they were common on the road. But, if you were a working-class chap, and a car was beyond your budget, you may still be able to afford one of the hundreds of motorcycle models available, especially if you used a hire purchase scheme. There was also extreme poverty here, and the Depression hit everyone hard. But GB was better off than most of the world. With so many vehicles manufactured here, we did not need to adapt the cheapest classes of vehicles to other uses. However, in the third world, roto-tillers (cultivators) have been used as regular vehicles since their invention. I took the above photo in Lhasa, Tibet, in 1995. It’s a local taxi. I recently visited Sri Lanka and the same type of vehicle is common outside the cities. The BMB Cultmate may have started its life as a two-wheeled hand-pushed cultivator, but fitting a rear end to turn it into a four-wheeler was common practice and, from there, it was a logical step to turn it into a full tractor.

 The Cultmate instruction manual, below, has been reprinted.




Ampton St London WC1


The British Motor Boat Co Ltd were an innovative company. As well as their marine products and newly-introduced range of cultivators, in 1935 they produced a remarkable 98cc Villiers-powered miniature car called the Rytecraft Scoota-Car. More than 1000 were manufactured, until the War halted production and the company merged with Brockhouse Engineering. The cars received favourable publicity and were even driven around the world!

This BMB tractor’s design is interesting to compare to the Rytecraft, both being smaller versions of established vehicles.

 To read more of the history of the Rytecraft, visit – http://sb-vintageservices.co.uk/the-history-of-rytecraft-scooter-car-new/