Sidepodcast // All for F1 and F1 for all

The evolution of fireproof socks // Progress in F1 driver safety

Published by Bridget Schuil

Kovalainen's F1 boot
Credit: Coates/LAT

Humans have used fireproof clothing for centuries. The earliest reliably documented use of fireproof clothing was in twelfth century Arabia; warriors would don silk undergarments, a cotton tunic daubed with a sticky fireproof substance, and a barrage of fireworks. Then, for some reason, the technology was forgotten until humans started venturing into space and incinerating themselves on race tracks.

Nomex creations

When motor racing first started, overalls existed simply as protection from oil stains. They were lightweight, made of cotton, and paired with flammable gloves and goggles that were very efficient at getting very hot. No helmet. No specific under-layers. If one caught on fire, one climbed out the car before following safety procedure and doing the ‘stop, drop, and roll’ anti-fire dance.

In the early 1960s, a Scot by the name of Wilfred Sweeny was working for Du Pont on a project sponsored by the US Army. His legendary invention? Nomex. A variation of nylon, Nomex fibres alter their molecular structure at approximately 370°C to form a protective coating.

After Jerry Unser Jr’s death from burns at Indianapolis, Du Pont approached Hinchtown, a racewear manufacturer. Nomex overalls were adopted in the US in 1966, first worn by Mel Kenyon at the Indianapolis race that year. It was a single layer thick, and military testing showed that two layers were better than one. And thus the tradition of Nomex underwear started. Thanks to the work of men like Prof Sid Watkins, these safer overalls made their way across the Atlantic to be used by the F1 racers of the day.

The 1970s saw a brief flirtation with asbestos. Because suits were now manufactured with two or three layers, some drivers felt unbearably hot, and some drivers preferred the lighter, more breathable single-layer asbestos suits. Meanwhile, other drivers – notably Lauda, Andretti, and Reutemann – preferred NASA-style quintuple layer Nomex creations.

These thick suits came at a price. The thicker fabric overheated the drivers, meaning their reaction times slowed. Stand 21 developed a thinner suit, giving the drivers who used it increased comfort. Being French, and thus quite adept at tailoring, the new design also included floating sleeves – more room to move in the arms. The 1986 design also included a wicking system to draw sweat away from the drivers’ bodies and trap a thicker layer of air between a driver’s skin and any potential fire.

The floating sleeve design

In 2002, stringent and comprehensive regulations were introduced governing the structure and composition of race overalls[1]. Everything – from threads and zips to socks and elastic – must perform to a strict set of guidelines. For example, a zip must not melt in a fire or transfer heat to the driver’s body.

Webber sporting some fireproof underwear
Webber sporting some fireproof underwearCredit: Thompson/Getty

Modern race suits built on the floating sleeve design, and now incorporate fabric ‘handles’ at the shoulder. While not a fire-retardant strategy, they are nonetheless safety features, as they allow drivers to be lifted out of the car while still strapped into their seats; they must be strong enough to support the weight of the driver and his seat. The suits are washed and dry cleaned fifteen times each before testing, and then subjected to temperatures between 600 and 800°C[2]. The temperature inside the suit cannot exceed 41°C for at least 11 seconds. In a potential fire situation, this would allow the driver to climb out of the car before being incinerated – even if his suit had seen a few washing machines.

Today is Lost Sock Memorial Day. So, ladies and gentlemen, charge your glasses and join me in a toast. To great scientists like Wilfred Sweeny and Sid Watkins whose work makes such amazing safety technology possible. To all the fireproof socks that reached critical rotation and slipped through the magic portal known as Die Waschmaschine into the Universe of Lost Socks. And, perhaps the greatest toast of all, to the fireproof socks that perished saving a racer’s life.