F1 Pit Stop
Here, you will see a life-size model of a Formula One car and others done in order to resemble a real pit stop. You will be taking part in the Pit Stop Challenge here. In doing so, you need to team up together to form the Pit crew which is made up of 13 persons. Hence, one has to be a ‘Lollipop man’, four to be Tyre changers, another four to be Tyre Carriers, one to be Fuel man, two more to be Jack men, one more fire extinguisher man and lastly one starter man. Each one of you has a specific role to try and see if the pit stop is within 5 sec, which is the requirement in Formula One. Currently, McLaren hold the record for the fastest tyre change; it took them just 3.8 seconds!
The Formula One Pit Stop
In motorsports, a pit stop is where a racing vehicle stops in the pits during a race for refuelling, new tyres, repairs, mechanical adjustments, a driver change, or any combination of the above while the driver waits inside the car unless a change is driver is involved. This allows cars to carry less fuel, thus be lighter and faster; and allows the use of softer tyres (refer to Area 2 Exhibit 6, F1 Tyres) which wear faster but provide more grip. In Formula One, the pit stop has become one of the most intense and an important aspect of the Grand Prix and it is not simply a refueling exercise. With overtaking are rarer than ever, but with the combination of a car's tyres and fuel level which are used to try and gain speed in a well executed pit stop, a clever strategy complemented can make the difference between winning and losing a race as half a second lost in a pit stop can make a difference of four or five places (refer to Strategy of the Pit Stop.
The Pit Crew and their Roles
Each pit crew consists of a few to as much as 29 mechanics from the race team who work on each car (refer to Figure 1) and in the garages before the race. There are no restrictions on the number of people allowed to make up each pit crew. Once, twice or even three times a race, the pit crew on each car is called into action to fit fresh Bridgestone tyres, refuel and carry out emergency repairs or changes if necessary. For example like making adjustments to the front and rear wings and perform minor repairs, most commonly replacing the nose and front wing assembly. In fact, there are no regulations limiting what can be changed on the car once the race has started. Everyone in the crew is on high alert to make sure the pit stop goes as smoothly - and as quickly - as possible within very tight timing. Therefore even when the car is approximately one lap away from making its stop, the pit crew will prepare the fresh tyres and all of the required pit equipment. The majority of the pit stops take less than 7 seconds. The pit crews spend hours practicing in order to fine-tune their technique to shave vital fractions of a second off their best times in order to reduce the time lapse for the pit stop as much as possible. Throughout the race, they are on stand by prior to the car’s arrival, ready to react instantly if they are required, with the exception of the rear jack man.
As refuelling is a potentially hazardous situation, the mechanics in the pit crews are all wearing fire-resistant multi-layer suits, flame-resistant gloves and balaclava which are made of Nomex® (refer to Area 2, Exhibit 7, Formula One Fire Safety); long underwear, helmet, socks and shoes. These have to meet the guidelines set by FIA Standard. Thus the clothes of the pit crews are very much like the outfit of the drivers.
The Lollipop Man or Pit Stop Controller
He is usually the Chief Mechanic and co-ordinates the mechanics’ work. He can be seen holding the pole with a round sign at one end, thus named ‘lollipop’ (refer to Figure 2), in front of the car on a grand prix weekend. His first job is to guide the incoming car to the exact stopping point by lowering the 'lollipop' to a stop position right in front of the driver's helmet. He also reminds the driver to keep the brakes on by showing the ‘brakes on’ sign on the ‘lollipop’ so that the tyres are not spinning during the stop. When the four tyres have been changed and jacks are lowered, he will turn over the sign to show ‘first gear’ to signal the driver to engage first gear. He can only lift the lollipop if he is sure that all the four tyres have been attached by seeing four hands raised in the air (refer to the Process of a Pit-Stop), the refuelling is completed and there is not another car to be in the driver's path, making it sure that it is safe for the driver to re-enter the pit-lane. The Lollipop Man is the only person in radio contact with the driver. As the driver races towards him at 100kph, he risks being run over by the driver. Hence he must stay cool and relaxed always.
Refueller or Fuel Man
(refer to Figure 3) is supported by two other mechanics. He has to lift a heavy
fuel rig (standardized and provided by FIA and teams are not allowed to modify
it), which has a mass of about 250kg when empty, over his shoulder and get it
into the tank the moment the car arrives and halts outside the garage to begin
the refueling process. The refueller handles the hose
itself by attaching it to the car’s fuel receptacle and another crew member
presses on the 'dead man's handle' which has to be kept down in order to fuel
the flow. The rig delivers 12 litres of high-octane fuel a second. Attached either to the hose or to the refuellers' helmets are indicators showing when the fuel is
flowing and when the process is completed. As soon as these indicators tell the
refuellers that the car is full-up, they release the
handle and the fuel stops flowing. The refueller will then remove the hose from the receptacle. Overseeing the whole operation are two other
crew members, each with a 60-liter fire extinguisher (refer to Firemen)
They are made up of crew members which are on standby with a 60-liter fire extinguishers in the unlikely event of a fire breaking out (refer to Figure 4) during the pit-stop especially during the refueling (refer to Refueller) while the engine is running. Thus they do not actually work on the car. However, their role is still very important since the risk of fire does exist.
There are two people in charge of the simple lever-type jacks - a tool used to manually lift the car off the ground and permit the changing of the tyres. There is one Jack Holder for the front (Front Jack Man) and one for the rear (Rear Jack Man). They use levers to lift the car off the ground immediately as it comes in for its pit stop.
Front Jack Man
The front jack man (refer to Figure 5) lifts the car clear of the ground using the front jack as soon as he is sure the car is in the right position to allow the fuel nozzle in. This also enables the tyres to be replaced. He is required to stand directly in front of the car as it enters the pit stall. If there has been an accident and the nose section needs changing, he needs to remove the broken one. Therefore, the job of front jack man is considered the most hazardous while the rear jack man is the only team member not in his working position before the car enters its pit stall.
2) Rear Jack Man
The rear jack man has to wait until the car has passed him before getting into position. He then places his jack beneath the car and raises the rear of the car in order to lift the car clear of the ground so that the tyres can be replaced.
Tyres Changing Crew or
They are in charge of making sure the old tyres come off the car (refer to Figure 6) and are replaced by new ones. Each tyre usually has two to three crew members. One operates the compressed air-driven gun that removes the single, central retaining nut. Then one of the other mechanics removes the old wheel and one fits the new one. The gun man then re-attaches the nut and tightens it to around 500 lb/ft (pounds per foot). Aside from changing tyres, one of them is responsible for cleaning the driver's helmet visor - an important job when drivers do in excess of 300kph and need to see where they are going. If the driver requires aerodynamic modifications to his car, two of the tyre changers are prepared to make front and rear wing adjustments.
He is a gearbox mechanic who does
not normally work on the car but is ready with a starter tool and a spare jump
start battery to manually restart the car from the rear if the driver stalls
the engine during the stop. He also
clears debris from the radiator.
Other Pit Crew Members or Mechanics
Besides the main crew members of the pit crews from all teams as listed above, there are some crew members on standby; or some teams have more mechanics with roles specific to the teams themselves. For example, Mclaren has a mechanic with spare scissor jack to lift the car in the event either the nose or rear lifting point are badly damaged or missing; and also a crew member to clean the drivers visor during the pit stop. Two members may check the pressurized air for the engine’s pneumatic valve drive and top it up as necessary. There are also crew members maybe placed at the sidepod entrance to reach in and remove debris from the radiators to prevent overheating and engine failure. An engineer is also needed to co-ordinates information and instructions from Senior Engineers/Tacticians on the pit wall gantry.
The Pit Stop Process
Step 1 – Arrival
Before arrival, the driver's race engineer
tells him over the radio, usually on the preceding lap, when to pit. When making the pit stop, the driver enters
the pit lane at full speed but brings the speed down to the pit lane speed
limit of 80km/h (some is only 60km/h in a very tight pit lane, like in
Step 2 – 1 to 2 seconds
Jacks are then inserted into the front and rear of the car to lift it up to about 2 inches as the mechanics remove the tyres by using air-driven guns to remove the nuts. The fuel hose is attached to the car’s filler for refueling. A valve ensures that the fuel only starts flowing when the pipe has been correctly fitted. One refueller handles the hose while the other presses on the ‘dead man’s handle’ which is kept down in order for the fuel to flow. Moreover, a red light in the visor of the refueler’s helmet signals that the pump is not yet ready and that fuel is not flowing. A green light signals all clear for refueling, and yellow that the fuel is flowing.
– 2 to 4 seconds
As the fuel is going in, new tyres are attached and air intakes are checked for blockages. The wheel nuts are re-attached. As soon as the new tyres are secured, the mechanics raise their arms in the air to show they have finished. The replacement of the tyres takes about 4 seconds.
Step 4 – 4 to 5 seconds
As all the four tyres have been changed, the car is lowered to the ground by the jack holders and the last fuel is pumped in, after which the ‘dead man’s handle’ is released to stop the fuel flow. Sometimes, if necessary, wing adjustments are made. The lollipop man then rotates his board and tells the driver to engage first gear.
Step 5 – 5 to 10 seconds
The tyre changers step away from the car and one of them cleans the visor of the driver’s helmet. If the light on the visor of the refueller’s helmet turns green, the fuel hose is detached and the car is ready to go. The lollipop man checks for traffic and makes sure that the new tyres are secured and refueling is completed. He then raises the lollipop up to signal the driver to engage in first gear.
As the driver is leaving the pits and crossing the line denoting the end of the pit lane speed limit, he disengages the speed limiter and the fuel flap automatically closes. He then accelerates hard back up to race speed.
Strategy of the Pit Stop
The aim here is to complete the pit stop as fast as possible. Those pit crews devote a lot of energy to working out the fastest strategy for their drivers and each pit stop would normally take less than 10 seconds. They usually plan for each of their cars to pit following a planned schedule, tyre lifespan, tradeoff of time lost in the pits versus how much time may be gained on the race track through the benefits of pit stops; and the number of stops as determined by the fuel capacity of the car (examples of this are shown as follows).
- 6-7 second first stop = 45
kilograms of fuel, normally indicating a three-stop race strategy
- 8 second first stop = 65 kilograms of fuel and normally means a two-stopper
- 10-11 second first stop = 80 kilograms of fuel and means a one stop strategy
Choosing the optimum pit strategy of how many stops to make and when to make them, taking into accounts of factors like fuel comsumption, the weight of fuel, cornering speed with each available tyre compound; rate of tyre wear, the length of pit road and and even the expected changes in weather and lighting conditions, is crucial in having a successful race. Pit strategies generally call for between one and three scheduled stops, depending on the course. The car that made the additional pit stop will run faster on the race track than cars that did not make the stop, both because it can carry a smaller amount, and thus lower weight, of fuel, and will also have less wear on its tires, providing more traction and allowing higher speeds in the corners. It is also important for teams to take competitors' strategies into account when planning pit stops, to avoid being "held up" behind other cars and unable to overtake them. The pit strategy is thus also calculated carefully so that the amount of time to be "given away" to other competitors in pit stops is balanced out by the time gained while on the track, resulting, theoretically, in the shortest possible time to cover the scheduled distance. An unscheduled or extended stop, such as for a repair, can be very costly for a driver's chance of success, because while the car is stopped for service, cars remaining on the track can rapidly gain distance on the stopped car. The teams are also practicing hard for the pit-stops. For example, Vodafone McLaren Mercedes conducts approximately 1,260 practice pit-stops throughout the course of the Formula One season.