Victor Harman explores another great British achievement. This time, it’s the Gardner Diesel

There’s a strong whiff of nostalgia about this nomination. Diesel old-timers will smile, particularly those with road haulage and PSV connections, recalling gentler times past and a rather special brand of engineering that may now be history, but has some close parallels to the present day. ForGardnerdiesel engines were all about fuel costs and fuel economy, which has always been vital to commercial vehicle operators.

Lawrence Gardner founded the engineering company we know as Gardner Diesel back in 1868, and his first Type O stationary engine appeared only in 1895. LaterGardnerengines followed, powering small ships and canal boats, the 1913 model 4VT being a particularly interesting single-cylinder two-stroke. Rated at 12hp, it required blowlamp heating before starting with a short rope looped over a peg on the flywheel, like a lawnmower pull cord. Maybe that was the start of the legend that Gardner engines, even big ones, were built to such fine tolerances that they could always be turned over easily with a starting handle.

There were 75,000 vehicles in 58 countries driven by a power unit produced with the engineering skills of Gardner, and a workforce in good times approaching 3,000

But the 1930s saw the real origins of the Gardner legend, based on a series of engine ranges designed for buses, boats, and trucks that happened almost by chance.Gardnerhad built their reputation mostly on heavy stationary and marine engines, but MAN and Benz inGermanywere then developing lighter diesels for road transport. British truck operators began to envy the economy and low price of diesel (four pence a gallon) compared with petrol at one and sixpence a gallon, which then powered most commercial vehicles. Nottingham bus operator Trevor Barton fitted a heavy 5.6 litreGardner4L2 marine diesel engine into his petrol Lancia bus, the word got around, and others succeeded with similar petrol to diesel conversions. L Gardner suddenly found themselves major suppliers to the haulage and passenger transport industry.

By 1931, with around 200 of the “L” range engines already in service, Gardner introduced a new, lighter, and faster-revving LW range. By employing cast aluminium extensively, the power to weight ratio leapt by over 60 per cent, and this modular series of two to eight cylinder units became legendary for their quality, longevity, and frugal fuel consumption. In Britain they led the displacement of spark ignition petrol engines from the heavy road transport and bus market, whilst Gardner later became suppliers of diesel engines for locomotives, such as the 24-litre 8L3 used in British Rail 03 and 04 series shunters. All these direct injection engines were very economical, attaining fuel efficiencies of over 40 per cent in some applications in spite of being only naturally aspirated. The LW range ran for well over 30 years, supplemented by the updated LX range using dry cast iron cylinder liners.Gardnerengines were typified by remarkably flat and wide torque outputs at engine speeds between 500rpm and 1,800rpm and this flexibility, which drivers loved, was a major reason for their incredible fuel economy.There were 75,000 vehicles in 58 countries driven by a power unit produced with the engineering skills of Gardner, and a workforce in good times approaching 3,000

Just as with the British motorcycle industry, wartime, new foreign machinery, and low investment brought about Gardner’s demise. As recently as 1994, L Gardner records revealed that there were 75,000 vehicles in 58 countries driven by a power unit produced with the engineering skills of Gardner, and a workforce in good times approaching 3,000. After a brief flirtation with high power, high-revving, engines and the disastrous arrival of turbo-charging in the 290hp 6LXDT and 320/350hp 6LYT engines, Gardner took part ownership of Cheshire truck manufacturer ERF. Soon after that, under the disinterested ownership of Hawker-Siddeley, the last vestiges of the company finally faded into the sunset in 2003, leaving magic memories best described by the words of one of its many remaining enthusiasts: “Ah! The incredible, indestructible Gardner – one of the great unsung heroes of British engineering!”  

But more than just mere memories remain. Many Gardner engines are still giving sterling service, from fairground generating sets to quarrying diggers, to paddle steamers on the Nile, and in hundreds of restored trucks, buses, and locomotives. There are a good few more Gardner powered Land Rovers and Rolls Royce cars than those pictured here, for this was a popular conversion using the 4LK engine, which produced 57hp from its 3.8-litres at 2,100rpm, weighing just 300kg. Interestingly, this same engine powered two midget submarines that crippled the WW2 German battleship Tirpitz in a Norwegian fjord in 1942, thereby making a significant contribution to victory in the war at sea. A full history of L Gardner and Sons appears in “Legendary Engineering Excellence” by Graham Edge.