24h Le Mans
24 HOURS CENTENARY – PERPETUAL INNOVATION ⎮ Our previous articles on track surfaces and on the 24 Hours circuit’s role as a testing ground, confirmed with an official label in 1931, have proven that the technological innovations to emerge from the race go far beyond road surfacing. Several forms of signage first seen at the circuit have since been used on the French and international road networks. However, the signs and signals used specifically in racing have constantly evolved over the last 100 years, along with the overall track infrastructure. The aim is the same every time, however: improving safety for competitors without spoiling the entertainment for spectators.
To identify the outer limits of the corners, posts equipped with retroreflectors – red or white depending on which side of the track they were placed – were installed on all the circuit’s bends in 1933. Then came a light strip on the crest of the outer fascine (or bank) of the Dunlop curve, followed by small matt black poles topped with reflectors, offered by Lucas. Later, French lighting company Cibié marked the run-off from the Dunlop curve using reflective studs set into the ground.
The circuit also led the way with the use of safety barriers. “Fascine” is the name given to the wooden-fronted embankments found around the circuit. These stood a metre high and were formed using sand from the heathland that the circuit was built on. They were fronted with wooden stakes assembled using pleaching or flexible wattle construction techniques, and provided an effective barrier to keep cars from “straying” off the track. A double row of barriers was later installed in 1964.
When the circuit was rebuilt after the Second World War, the latest security features were introduced. For example, sandbanks (sometimes two) were placed at the exit of the bends as a means of preventing brutal collisions in the event of a spin off track. The only problem was that it was difficult to get the cars out of the sand, although this made for some great stories that are now part of the race’s iconic history! Take, for example, Count Biaggi shovelling sand in a suit and bow tie at Tertre Rouge, or Teodoro Zeccoli sweating in his underpants at Mulsanne, where the race came to an early end for him, Brian Muir and their Ford GT40 in 1968.
The first chicane, funded by Ford, was introduced in 1968. Several others were added after that. In the 1970s, in partnership with the American company 3M, a large-scale signage programme was implemented at the circuit, including retro-reflective panels and reflective beads fastened to the safety rails which, when viewed at speed, formed a luminous strip on either side of the track, making things much easier for drivers at night or in the rain. Several long nights were spent carefully adjusting the track’s lighting masts to complete this set-up.
In the 1990s, “rumble strips” were introduced. These are cement structures placed at the tangent points of the racing lines to discourage competitors from cutting corners. Later came the highly dissuasive, so-called “banana” traffic calming devices bolted onto the track surface.
Gravel traps (shallow pits filled with smooth round gravel, often extracted from the bed of the River Loire) first appeared in around 1986 to help drivers or motorcycle riders slow down instead of hitting the barriers when spinning off track. They are now widely used but are gradually being replaced by tarmac run-off zones to overcome the problem of gravel being projected onto the track. The only drawback is that these areas make a lot of extra work for Race Control, with the notions of “track limits”, meaning numerous lap times are invalidated during free practice and qualifying, and penalties issued during the race.
From the very first race in 1923, the sections of the track deemed “tricky” were lit up by acetylene gas-powered lamps from the company Magondeaux, which supplied headlamps to the rare cars that used to venture out onto the roads after nightfall. Today, there are huge lighting masts all around the circuit.
In the 1950s, a system of orange flashing lights coupled with an audible alarm was tested at Mulsanne, then fitted all around the circuit in 1966 to alert drivers as required.
There was also innovative use of horizontal and vertical signalling with the white centre line introduced in the 1920s, followed by Reflect-brand retroreflective panels that reflected light around difficult corners.
Light signalling systems have also made considerable progress. They are managed on the ground by the marshals but centralised by the track control centre, which can take over remotely if required. This has led to huge safety improvements for marshals and information can be shared at unparalleled speeds with drivers. The CCTV networks inaugurated at Le Mans in 1985 are also amazingly efficient during the day but also at night, and have inspired circuits the world over.
PHOTOS: LE MANS (SARTHE, FRANCE), 24 HOURS OF LE MANS CIRCUIT – TOP TO BOTTOM (Copyright: /ACO ARCHIVES): lighting, safety barriers, chicanes and gravel traps are just a few of the features added to the 24 Hours circuit over the years.
