The Mercedes Formula 1 team has revealed the decision to stack both of its drivers at the pitstop during the Chinese Grand Prix was the idea of team boss Toto Wolf.
Holding a comfortable one-two during the race, Mercedes’ result was in jeopardy after Red Bull opted to bring in Max Verstappen for a second stop.
The strategy forced cars ahead to react to the Dutchman’s pitstop to prevent being undercut, Ferrari quickly responded by pitting lead driver Sebastian Vettel.
As the German had been running in third-place, Mercedes realised it too would need to pit its drivers to cover Vettel, but were unsure how it could execute a response without at least one driver losing track position.
While the Brackley-based outfit weighed up its options, Wolff suggested the team should consider stacking both Valtteri Bottas and Lewis Hamilton.
Chief strategist James Vowles overlooked the possibility of a double-stack and confirmed it was possible to go through with, discussing the idea with sporting director Ron Meadows, before he approved the plan.
In Mercedes’ post-Chinese Grand Prix debrief on its YouTube channel, engineering director Andrew Shovlin said: “It was actually Toto who suggested that we do a stacked stop.
“That then becomes a discussion between James Vowles and Ron Meadows. Ron is the sporting director and he is just checking that he is comfortable with the gap between the cars, that we can get the pit crew ready to do the stacked stop and have both sets of tyres in the pitlane.
“James is the one who gets the final decision on this and he decides to go ahead with it.”
Stacked pitstops are something of a rare occurrence during grand prix’s and is rarely practised by teams. Shovlin explained the team prepares as much as it can for this type of situation but admits there is a lot of risk involved.
“You don’t have two cars to practice with,” he said. “We do have a pitstop car and we can practice getting both sets of tyres out, we can practice doing two stops in succession but you can never quite get the same situation with the car rolling into the box.
“It is quite difficult for the rear jack man as he has to get out of the way when the first car leaves and then get into position when the second one comes in.
“The choreography is quite tricky, there is a bit more to organise. Having that many tyres in the pitlane is a bit of a risk, so you have to make sure the right tyres go on the right car. But it is something we do as much preparation for as we can.
He added: “You try not to do them unless you have to because if you have any problem with the first car, it also impacts the second – and you can go from being first and second in the race to third and fourth in no time.
“It isn’t something you do every day, but on the occasions it makes sense it is a really tool to have in your tool set.”