The first turbocharged world championship racer – from the 1920s

It contested just two grands prix but the Halford Special, now being offered for sale for the first time since the present owner acquired it as a collection of spare parts in the late 1970s, gives us a glimpse of a bygone era of invention and ambition. The practical application of turbocharging was still in its infancy when the car’s creator, a former Royal Flying Corps engineer, tried to introduce it to the racing world single-handed.

Those who follow what’s now known generically as Formula 1 will be well aware the world championship is celebrating its 75th anniversary this year. You might even have a pricey ticket to the glitzy season-launch event at London’s O2 later this month.

What’s rather less well known is that in the mid-1920s the forerunner of the FIA tried to stage a world championship, only to abandon the idea after three seasons of almost continuous destabilising rule-tinkering in service of trying to appease too many stakeholders. It was an experimental era in which the thunderous big-banger bolides favoured in the first two decades of the century were legislated out in favour of (theoretically) nimbler designs powered by smaller, often pressure-charged engines.

It was also a time of French rather than German domination of grand prix racing, before Nazi government-backed projects swept all before them. Indeed, Adolf Hitler had yet to acquire syphilis, let alone the keys to the Reichstag.

Just as representatives of the booming French car industry had dominated the early grand prix racing scene, the French national auto club (also chiefly responsible for the term ‘grand prix’ being applied to high-level motor races) was among the loudest voices within FIA’s ancestor, the Association Internationale des Automobile Clubs Reconnus (AIACR) and its sporting commission. One debate in 1929 regarding the circulation of general assembly decisions would memorably conclude “in case of dispute, the French text is to be used”.

Nevertheless the growing might of Italian manufacturers – chiefly Alfa Romeo, which had many of the star drivers – made Italy’s national club something of a kingmaker. The tug-of-war between national interests would account for what became a bureaucratic tangle as the august AIACR attempted to codify a common set of internationally acceptable technical regulations.

Having first been floated in 1923, the idea of a World Manufacturers’ Championship stuttered into life two years later as a best-three-out-of-four-races deal in which the Indianapolis 500 (with just one European car entered) was first on the calendar. Owing to the influence of the Italian national club in backing the championship, attendance at the Italian Grand Prix was compulsory, while a planned event in Britain – then, as perhaps now, considered not part of Europe and therefore an important thread in this ‘world’ series – was dropped for fear of friction with residents living near the purpose-built Brooklands track.

Major Frank Halford and his self-built car that took on the manufacturers

If this didn’t seem sufficiently chaotic, add in an almost wilfully counter-intuitive reversed points scheme in which the manufacturer with the smallest total at the end of the season was declared the winner. What a shame the BBC’s Pointless host Alexander Armstrong wasn’t born a century earlier; he could have presented the trophy.

Entries were ‘select’, Alfa Romeo won the championship and then withdrew, reckoning to be unable to afford development costs, and for the following season maximum engine displacement was reduced to 1.5 litres. This opened the door for Major Frank Halford and his self-built car to take on the manufacturers – including Mercedes, now Germany’s national club had been admitted into the AIACR.

This was by no means Halford’s first racing rodeo. Postwar he had worked with the eminent engine designer Harry Ricardo, acting as Ricardo’s Engine Patents Ltd’s sales agent in the USA and collaborating on the design of a 500cc Ricardo motorcycle engine – which Halford raced at the Isle of Man TT.

Besides being the world’s first purpose-built racetrack, Brooklands epitomised the intersection between aviation and high-performance automobiles in the early 20th century. It was from the airfield here that Sir Edwin Alliott Verdon-Roe, British aviation pioneer and founder of the Avro aircraft company (and grandfather of future Autosport MD Eric Verdon-Roe) undertook his first flight trials. Sopwith and Vickers established bases here, as did the Bristol Aircraft Flying School where Halford learned to fly.

Deciding that the engine was the weakest element of the package, Halford resolved to build his own

Halford was thoroughly embedded in this milieu, not just as a sometime racer at ‘The Track’ but also as an eminent figure in the aviation industry, the designer of successful aircraft engines and holder of an influential role in the Air Ministry. Having set up as an independent consultant after leaving Engine Patents Ltd, he was involved in government-backed efforts to dispose of war-surplus inventory for profit, redeveloping existing engines for onward sale.

He was also one of several people providing loans to keep afloat the Bamford & Martin company, builder of Aston Martin cars. Co-founder Robert Bamford had already departed when the outfit produced three grand-prix-style cars in 1923, and it was the third of these – believed to be the first Aston Martin-badged car built for sale to customers – which Halford acquired crash-damaged after George Eyston shunted in a voiturette race in Boulogne.

Deciding that the engine was the weakest element of the package, Halford resolved to build his own. By the time it was ready, the donor car’s manufacturer would be wrestling with the first of its many insolvencies and changes of ownership.

Halford's own two 1.5-litre straight-six engines used his aviation experience to guide their creation

Photo by: Matt Howell

Halford built two 1.5-litre straight-six engines drawing on his aviation experience, specifying aluminium blocks and crankcases to reduce weight, and designing the cylinder heads with double overhead camshafts actuating inclined valves to improve the mixture dynamics. While grand prix cars used superchargers to yield greater power from small displacements, Halford – for reasons undocumented – took the hitherto unprecedented step of trying to turbocharge his engine.

This is believed to be the first attempt to apply turbocharging in the world of motor racing.

The principle of using exhaust gases to move a turbine which then compressed incoming air was established at this point, if not actually productionised. Supercharging – similar principle but with a mechanically driven turbine – had been patented by Gottlieb Daimler in 1885 but came freighted with disadvantages since it used some of the very power it was creating. The turbo, first subject to a patent in 1905, offered higher theoretical efficiency since it was in effect using energy being expelled as hot gas rather than engine power.

Given Halford’s role in the aviation industry he is likely to have known of contemporary research undertaken by the Royal Aircraft Establishment to use turbocharging to improve aero engine power and efficiency at altitude. Supercharging had proved problematic in aircraft engines because the additional rotating weight at each end of the crankshaft tended to induce torsional failures. Halford would certainly have been aware of this because he had been involved with Ricardo in modifying one of his own aero engine designs for testing.

Turbocharging brought its own challenges, though, particularly around management of pressure in the exhaust and the fuel ratio of incoming air, and it wasn’t until around the time Halford abandoned his experiments that a turbo was first productionised – in a railway engine. The aviation industry wouldn’t get there at scale until the 1930s, grand prix racing until the 1970s.

For his car engine Halford ran a centrifugal ‘blower’ under the sump driven by an axial turbine in the exhaust, with the compressor plumbed in after the carburettor to ‘suck’ air through. In testing it suffered many of the issues which had afflicted the early turbocharged aero engines – rotor element failures in the turbines, sub-optimal performance caused by fluctuations in the air/fuel ratio – which prompted Halford to drop it in favour of a conventional mechanical supercharger.

In this early form the engine produced a quoted 96bhp at 5300rpm and Halford entered the car as the AM-Halford for at least two documented races in 1925, notably the Junior Car Club 200-mile event which used a new track layout at Brooklands incorporating an infield section with a hairpin turn opposite the paddock. Sources differ as to his finishing position – it was a multi-class event – but the car was stymied water and fuel leaks and Halford can be seen pushing it in one of the old glass-plate photos in the Motorsport Images archive (below).

Reliability ever the cause of revision, Halford required changes for 1926

For 1926 Halford fitted his second engine, with a larger Roots supercharger and twin magnetos, reckoning to bring power to 120bhp at 5500rpm. In parallel he sought to cure overheating issues with a deeper radiator.

It was in this form, and repainted in British Racing Green, that Halford entered the car as the Halford Special in August’s world championship round at Brooklands, which pedants revolt at being called the British Grand Prix (officially it was the Grand Prix of the Royal Automobile Club). There he lined up against stars of the day including Robert Benoist, Albert Divo and Andre Dubonnet, and British heroes Henry Segrave and Malcolm Campbell.

By this point in the circuit’s history it was becoming clear the ‘speedbowl’ was unsuitable for racing as originally envisioned, for despite remedial works the large concrete sections had settled and shifted, and the gaps between them punished tyres, suspensions, chassis frames and drivers when travelling at speed. Race organisers continued to experiment with alternate layouts and for this event the route cut out the northern section of banking, passing along the finishing straight via a pair of temporary chicanes.

This was the end of Halford’s grand prix career, for he sold the Special to George Eyston at the end of the year and focused on his increasingly successful consultancy business

In the absence of the works Bugatti team just nine cars started, giving Halford a reasonable chance, and, as other cars encountered mechanical maladies – Jules Moriceau’s Talbot was first out when his front axle sheared under braking for one of the chicanes on the opening lap – Halford found himself disputing third place with Campbell. In the final half of the race rising engine temperatures made the cockpits of the remaining Delages unbearably hot, prompting Benoist to pit again and request asbestos matting be wrapped around his car’s exhaust pipe, losing almost a quarter of an hour in the process. In the other car, a similarly afflicted Robert Senechal pulled in and dismounted in favour of Louis Wagner with 27 of the scheduled 110 laps to run.

Halford now stood to get on the podium at the very least, but at the end of his 82nd lap a universal joint failed as he gassed it out of the final chicane and his Special coasted to a halt. Could he have won, had his transmission held strong? Maybe, for Campbell was at that point running almost a lap behind, Divo’s Talbot broke down, and Wagner had to pit repeatedly in the final half hour to dunk his feet in a bucket of cold water.

Still, this was the end of Halford’s grand prix career, for he sold the Special to George Eyston at the end of the year and focused on his increasingly successful consultancy business, superintending the De Havilland Moth and Napier Sabre piston engines and the de Havilland Goblin and Ghost turbojets – the latter of which powered the world’s first commercial jet airliner, the Comet.

Faced with manufacturer interest declining from an already low bar, the AIACR capitulated to the inevitable in 1927 and announced that from the following year grands prix would be ‘formula libre’ (free formula) events. Just five races counted to the Manufacturers’ World Championship and no European manufacturers troubled themselves to visit the season-opening Indianapolis 500. The American manufacturers, crunching the numbers and deciding that the prize fund on offer was insufficient to justify the length and expense of the sea journey, riposted by not bothering with the next event, at Linas-Montlhery in France on the first weekend in July.

After Halford sold to Eyston the Special continued to feature in grand prix racing, despite the ever-changing scenery

Photo by: Matt Howell

This was another banked track which had recently been augmented, here with a road course. The Grand Prix de L’Automobile Club de France was the headline act of a three-race weekend, presaged on the Saturday by a Formula Libre race and the Coupe de la Commission Sportive, though only the latter achieved a decent entry.

Eyston arrived in France with a 2.3-litre Bugatti T35 as well as the Halford Special and finished on the podium in the seven-car Formula Libre race, albeit more than three minutes down on second-placed Louis Chiron. A poorly handled fatality – the ambulance removing Henry de Courcelles’ corpse from the roadside drove the wrong way down the track while the race continued – set the glum tone for the remainder of the weekend.

Deciding the Delages were too strong, Ettore Bugatti’s works team pulled out ahead of the grand prix but this fact wasn’t communicated to the crowd until the remaining entrants began to assemble on what had become a seven-car grid. Eyston, having drawn pole position in the pre-race lottery, therefore gunned the Halford Special off the starting line with a discordant chorus of boos and jeers still in progress.

Eyston’s lead lasted just fractions of a second – Divo nailed him away from the line – and by the end of the first lap he was over a minute behind all but one car (and then only because it had failed to fire up). He fell further behind as the race progressed, pitting repeatedly to have spark plugs changed and loose bodywork fitted. Delage’s Benoist completed the set 48-lap distance in 4h45m with second-placed Edmond Bourlier taking another 8m14s to reach that mark in his similar car. With just five cars remaining on the sprawling course at the finish the crowd and organisers grew increasingly restive and finally, nearly 40 tedious minutes after Benoist crossed the line, fourth-placed Jules Moriceau and Eyston were flagged off and told to pack it in having completed 42 and 32 laps respectively.

Eyston then sold the Halford Special on to the 3rd Viscount Ridley but held on to his other Aston Martin race car, registering a DNF at Le Mans the following year. He continued to race in a variety of machinery with mixed success, and in the late 1930s traded land speed records with Campbell and John Cobb in his twin-aero-engine Thunderbolt.

Ridley used one of Halford’s engines in his Bugatti Type 35 and another in his speedboat, which is reputed to have sunk. In recent years the reconstituted Halford Special has been on loan to the Brooklands museum and is now offered for sale via Ecurie Bertelli.

The Halford Special holds a special place in history even if its results were unspectacular

Photo by: Matt Howell