Aeroquip Hose

Now a generic and used in almost all racing cars, Aeroquip Hose started live in US Warplanes. Keith Howard looks at its brilliant and much copied design

photography by Charles Best

You know a company has created, or at the very least cornered, a market when its trade name is bandied about as a generic. It most famously happened to Hoover, of course, but for motorsport aficionados there are other examples.

The Rose bearing, subject of a previous Technofile, is one; Aeroquip hose and fittings are another. People may not always know how to spell it — I recall seeing it rendered as Air Equipe in a classic car magazine — but when they see a hose covered in braided stainless steel that's the name which springs to mind, even though these days the hose in question is likely to have been made by copycat competitors to the genuine Aeroquip Corporation of Ohio, USA.

Knowing the race industry's habit of poaching technologies developed for the aircraft industry, it's no surprise to learn the name Aeroquip was originally a condensation of aeronautical equipment. And ironically, given its products would be standard fitment on all American warplanes of WW2, the company was founded in 1940 in Jackson, Michigan by Peter F Hurst, a young German engineer. A week before the outbreak of war in Europe, Hurst arrived in New York as a representative of Argus Motoren, a Berlin-based aeronautical firm manufacturing engines, brakes and other components for Germany's busy aircraft industry. Opposed to Nazi policies, Hurst decided with the outbreak of hostilities to stay in the US and start up his own company.

Five years earlier he'd overseen the development of a brake hose assembly with detachable, reusable fittings for use by Focke-Wulf, followed shortly by a self-sealing coupling. It was this expertise Hurst reckoned he could sell to American plane makers.

As a business venture it couldn't have been better timed. Aircraft were already beginning to rely on hydraulics for operating flight controls, wheel brakes and landing gear. War only accelerated the process as variable pitch propellers, large bomb-bay doors and rotating gun turrets became further additions to the list of items that required powering. Multi-engine aircraft with ever more complex lubrication systems and the introduction of fuel injection added further to the need for durable, dependable plumbing.

Much of this could be realised as rigid pipe, but in certain key places a flexible tube was essential. One which could nonetheless endure both high fluid pressures and the rigours of aircraft operating conditions. A reliable means of attaching the hose to the piping was needed too. All this was grist to Hurst's mill, his self-sealing couplings gilding the lily by making servicing both easier and faster.

Aircraft manufacturers quickly appreciated the benefits of Aeroquip's stainless steel reinforced hose and reusable anodised aluminium fittings, and business boomed with the war effort. But the war years included personal frustration for Hurst: when Germany declared war on the US following Pearl Harbour, Hurst — still a German citizen — was banned from the Aeroquip factory, a humiliation that lasted 19 months.

The handing down of technology from aircraft to racing cars occurred more by accident than design. After WW2 and the Korean war, large amounts of used Aeroquip hosing became available as unwanted warplanes were scrapped. Designed to be reusable, it was secondhand only in price, not functionality. American motor racing engineers soon recognised the attraction of tough, vibration resistant plumbing to carry oil, fuel and water around their cars, and aircraft surplus suppliers like Earl's Performance Products soon found they had a major new business. Indycar builders were early customers, while NASCAR teams, dragsters and then all American motorsport followed as word spread. Lou Moore's Blue Crown Sparkplug Special was the first to carry Aeroquip components to Victory Road in the Indianapolis 500 of 1947, a feat repeated the following two years. By 1950 Aeroquip had an Indy 500 winner completely plumbed with its products when Johnny Parsons won for the Kurtis Kraft team.

Doyen of motorsport technical writers Carroll Smith has, as usual, a pragmatic, no-nonsense view as to why aircraft spec plumbing is no extravagance for earthbound race cars. "It doesn't leak. It doesn't come undone. It doesn't burst, collapse, wear through or wear out. (The protective braid will, however, abrade through just about anything that it comes into contact with.) It is highly heat and flame resistant. It's the lightest stuff that will do the job well and conveniently. It is versatile and indefinitely reusable. If it is not idiot-proof, then it is at least fool-resistant. It looks nice and is easy to keep that way." In other words, it would be folly to use anything else.

In specific applications, most notably brake pipes, Aeroquip hosing also offers a functional advantage. Its brake hose comprises an extruded PTFE tube sheathed, as usual, in that distinctive stainless steel braid. Because it better resists swelling under line pressure — and brake line pressures can comfortably exceed 1000psi — brake pedal travel is reduced, helping achieve the firm pedal racing driven demand.

Eventually stocks of surplus hoses and fittings that had proved a treasure trove to the American racing industry began to dwindle. Instead of grasping the opportunity that serendipity had placed in its lap and embracing motorsport as a new growth market, Aeroquip — with some justification, perhaps, considering how shoddily engineered many racing cars then were — stood on its dignity and shunned its eager new customer base. The supply situation became so bad Earl's took the brave decision to begin manufacture of fittings itself (the hose was available from other sources), metamorphosing from surplus supplier into an Aeroquip competitor. Aeroquip belatedly corrected its mistake and now includes BMW, DaimlerChrysler, Fiat, Ford, GM, Honda, Jaguar, Mazda, Nissan, Opel, Porsche, Renault, Rover, Toyota, Saab and VW among its major customers, alongside the list of aerospace companies, not least because its extensive product line-up now includes many cheaper forms of hose and fitting suited to a wider cross-section of the car market. But the chink it left in those critical years, together with the expiry of core patents, allowed rivals to gain a foothold.

Yet the name Aeroquip still has unique cachet Somewhere in my brain, certainly, and those of many others besides, there's a hard-wired equation that reads: "stainless braid plus blue/red anodised fittings equals Aeroquip."