The 24 hours of Le Mans is a statistician’s dream. One of the statistics that strikes a chord with me is the number of pit stops during the race. I have spent many hours in the pit lane capturing the drama as it unfolds. There are times when, like a predator stalking its prey, I have walked up and down the pit lane looking for something to happen, looking for the tell-tale signs of mechanics donning helmets and gloves and getting ready to fettle their car.
Often, in what seems an eternity, nothing happens, the only action it seems are the photographers on the lookout for some activity, and the pit lane marshals and FIA/ACO officials patrolling and making sure that all is in order. And yet the statistics for the 2016 race reveal that there were 1565 pit stops and in 2017 there were 1624 during the 24H race.( Thanks to Paul Trusswell for the statistics)
In a 24-hour period there are 1440 minutes, which means that on average there is one pit stop every 53 seconds!
In 2017, there were 60 entrants, and each car ran for 10- 14 laps or about 35 to 40 minutes between fuel stops. So, the statistic of 1624 pit stops makes some sense, but what is hard to reconcile are the long periods of inactivity in the pit lane.
In the context of all that is Le Mans there are periods of tranquillity in the pit lane, but there are also periods of frenetic activity, where the well-oiled, choreographed and rehearsed phenomenon of the pit stop is evident up and down the pit lane.
The 2017 FIA World Endurance Championship Sporting regulations runs to 113 pages, of which 11 pages relate to the humble pit stop:
Pit stops –Interventions on the car. Paragraphs 10.8.1 to 18.8.8.
So, what is a pit stop? It ranges from a fuel stop to a complete tyre change, driver change or a combination of all three. In addition, the teams take the opportunity to clear debris from the cooling ducts, clean headlights, windscreens change drivers’ drinks bottles and FIA official data logger dongles. These are usually planned stops, but there are also unplanned stops for punctures or a change of tyres due to weather change. These pit stops usually occur in the working area in the pit lane outside the garage, any other intervention must be carried out inside the team’s garage.
The pit stop activity starts a couple of laps before the car enters the pit lane, when the pit crew assemble in the garage, put on the required safety equipment and wait patiently for the arrival of their car. The pit crew consists of at least ten people, all of them have defined roles and know exactly what is expected of them.
1) The Car Controller or ‘lollipop man’ controls the entry and exit of the car into the pit lane and all of the operations carried out on the car whilst stationary in the pit lane.
3) Refueller
4) Vent man (unlikely to be seen after 2017 as technology now combines fuelling and venting in one operation)
5) Cut off valve attendant (Deadman valve): he or she cuts off the fuel supply in the case of fire.
4.7.1.2 The refueller, vent and cut off attendant must wear the following FIA homologated gear (amongst other prescribed items): FIA homologated uniform colour without decoration full face helmets with closed full visors
6) Cockpit Operator: this person is responsible for assisting drivers during driver change with belts, getting into and out of the cockpit, changing drivers’ drink bottles and FIA data logger dongle. These tasks can be carried out by the drivers themselves.
7) Mechanics: There are four mechanics who wear mandatory green armbands and are responsible for, whilst refuelling: cleaning windscreen, mirrors, lights, race numbers, onboard camera, removal of obstructions in air intakes and radiators.
After refuelling is complete the green arm banded mechanics carry out the wheel and tyre changes.
The crew described above are employed by the team, but in addition and included in the head count, are two blue arm banded technicians whose sole responsibility is for tyres and brakes – they are employed by Michelin, Dunlop, Brembo or AP, respectively. The function of the brake technicians is to take temperature readings and carry out visual inspection of the brakes. Their involvement is primarily concerned with checking the calibration of on-board brake temperature sensors. Once there is confidence in the correlation between temperature readings and the on-board systems, the work of the brake technicians tends to be in the garage or paddock, not the pit lane. Tyre technicians are often seen taking tarmac temperature readings as well as inspecting the tyres both on and off the car.
A full service pit stop starts with refuelling, and depending on the class, fuelling takes between 20 to 65 seconds.
10.8.2.4 For safety reasons, during refuelling: a) The car must remain on its wheels in case it needs to be pushed in an emergency
Whilst refuelling takes place the mechanics may clean windscreens, lights, numbers, clear ducts and radiators, but must not use tools. Tyre technicians (blue arm bands) can take temperature readings and undertake visual inspections. Drivers can changes can take place during refuelling.
Once refuelling is complete, the four mechanics with green armbands can approach the car to change wheels and tyres. Unlike F1 where there are four wheel guns, Le Mans and WEC pit stops only allow the use of one wheel gun at a time, although two wheel guns are available, an ‘inside’ and an ‘outside’ gun.
Tyre changes typically take between 15 and 19 seconds, during this time four wheels and tyres are taken into the working area, exchanged and removed from the working area, before the car can leave the pit.
10.8.3.2 For a wheel change, mechanics must: – Not throw the wheels or drop them
At the end of the pit stop (intervention) all tools, equipment and materials must be cleared away. Only once the working area is totally clear can the engine be re-started and the car leave the working area.
10.8.1.24 Any external assistance (push, etc) is prohibited when a car leaves its working area to rejoin the race
If the visit to the pit lane is for a mechanical reason requiring the car to visit the garage most teams will refuel and change wheels and tyres in the pit lane working area before the car is pushed rear first into the garage by a maximum of 4 mechanics.
Once the car is in the garage, there is no restriction on the number of people who can work on the car.
10.8.6 During the race, on pain of exclusion of the car, it is prohibited to change:
– the engine or any of its components, i.e. the cylinder head(s), the cylinder head gasket(s), the oil pan and engine block, components that are fixed to one another by means of seals;
– the main gearbox and differential housings;
– the chassis or the monocoque structure.
Whilst the car is in the garage
10.8.8. Access to the garage:
a) The pit shutter (on the track side) must remain completely open. An iconic sign that the race is all over is when the shutter comes down
b) Visibility towards the inside of the garage and the race car must remain free of any obstruction of any kind whatsoever
Any person standing in front of the car when it is inside the garage is considered to be an obstruction to the visibility towards the inside of the garage unless that person has to work on the car. A line of people in front of the car is strictly prohibited.
When the car is ready to return to the race, it must be pushed out of the garage by a maximum of four mechanics and placed in the working area parallel to the track. The driver must then start the engine on his own.
At the end of the pit stop, the car controller must be located close to the car on the fast lane side in order to instruct the driver of the precise moment in which to turn on the engine and the moment in which it is safe to leave the working area.
10.8.1.15 It is strictly prohibited to spin the wheels when a car leaves the pit
I was given the opportunity to have a chat with Jonny Adam, probably the hardest working driver in the northern hemisphere, about pit stops in the Aston Martin Garage.
Jonny Adam, driver of the #97 Aston Martin and winner of the GT Pro Class at the 85th 24H of Le Mans 2017, explained that Aston Martin engage openly with their guests and as a result the garage environment is very busy during a race weekend. And when the drivers are ready to enter the car for their stint, they are part and parcel of the AMR experience. It is only when the drivers are standing behind the white line on the garage entrance waiting for the car that they are completely isolated from everything around them. No radio chatter, no distractions – just standing there waiting for the car, watching pit crew members for the cue that the car is near and the ok to cross the white line and dive into the car. “It’s like waiting for a cab”.
“When you see the car or the distinctive headlights approaching, your heart rate goes up, your eyes widen and the adrenaline kicks in”.
“It’s vital to get the car on the right spot in the pit lane. If you’re too far forward or too short or off the centre line, valuable time can be wasted as the pit crew adjust to your new position. We use the lollipop as the stop point and the pitot tube on the bonnet to line up with the centre line in the pit lane”
“All the time you are relying on the pit crew, the car controller and radio coms, waiting for the moment when you can release the quick start and rejoin the race.”
Standing in the pit lane, the initial movement from the car going down on the jacks and pulling away is like an explosion of power, the exhaust gases hitting your leg is like being hit by a football. But in the car it’s all controlled and measured.
And finally – Following the 2016 24-Hours of Le Mans, which ended in victory for Porsche #2 and heartbreak for Toyota, Porsche released the following facts:
- Car #2 spent 38 minutes 5 seconds in the pits, it was refuelled 30 times
- The fastest refuelling stop took 65.2 seconds
- The fastest pit stop was 1:22.5 minutes.
- In 2017 the Porsche #2 won again but spent a total of 98 minutes in the pits
And you thought a Le Mans pit stop was a simple matter!
Written by: John Mountney
Images by: Virtual Motorpix/John Mountney
This is a subject not many people have bothered to study – for insiders and involved team members only. Illuminating!