How Mercedes made the insane stack-pitstop work

You cannot watch the replay of the way Mercedes stacked their cars for a pitstop during the Chinese Grand Prix and not be awestruck by the poetry in motion coupled to ruthless efficiency of a crew, at the top of their game, as they dispatched both cars in ten seconds flat!

From the moment Lewis Hamilton hit the marks for his pitstop to the split second Valtteri Bottas screeched out of the pit-box – with eight tyres removed and changed – was about the same time it takes Usain Bolt to run 100 metres!

Andrew Shovlin, Trackside Engineering Director shone light on how the team went about the stunning feat in the heat of battle in Shanghai, “I can give you a bit of the background, so lap 35 Vettel comes in that creates a bit of a dilemma for us because we have a decent gap to Vettel.”

“But, if we stopped Lewis first and Valtteri second there’s a risk that Vettel would be able to undercut Valtteri and take the position and if we stop Valtteri first to protect against Vettel and with Lewis
there was a chance that Valtteri would have undercut him so it put us in a slightly awkward position.”

“It was actually Toto [Wolff] who suggested we do a stack stop. That then becomes the discussion between James Valles and Ron Meadows. Ron is the sporting director and he checks that he’s comfortable
with the gap between the cars so that we can get the pit crew ready to do the stack stop.

“Have both sets of tires in the pit lane. James is the one who gets the final decision on this and he
decides to go ahead with it and what it allows us to do is to keep our two cars in the same order as they were before the stop and also protect against losing any positions to Ferrari.”

“On this occasion, it was the perfect solution and it was actually a really nice clean well-executed stop by the guys.

“Practising a double pitstop… well that’s one of the hardest things to practice because you don’t have two cars to practice with. We do have a pitstop car here we can practice getting both sets of tires [off] and we can practice doing two stops in succession but you can never really get quite the same situation with the car rolling into the box.”

“You can see it’s quite difficult for the rear jack man because he’s got to get out of the way when the first car leaves and then get into position when the second one comes in so the choreography is quite tricky there’s a bit more to organize and having that many tires in the pit lane is a bit of a risk.”

“You’ve got to make sure the right tyres go on the right car, but it is something we do as much preparation for as we can.”

At that point in the race, Mercedes were well in control of proceedings and stacking the cars was one of those ‘zero-or-hero’ moments which this time had a happy ending.

Shovlin acknowledged, “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 that you do every day but on the occasions where it makes sense it’s a really useful tool to have in your toolset,” he added in the wake of some of the slickest pit work ever seen in the top flight.