Formula 1
Formula 1
R
Emilia Romagna GP
18 Apr
Race in
46 days
09 May
Next event in
64 days
23 May
Race in
81 days
R
Azerbaijan GP
06 Jun
Race in
95 days
13 Jun
Race in
103 days
27 Jun
Race in
116 days
04 Jul
Next event in
120 days
18 Jul
Race in
137 days
R
Hungarian GP
01 Aug
Race in
151 days
29 Aug
Race in
179 days
05 Sep
Race in
186 days
12 Sep
Race in
193 days
26 Sep
Race in
207 days
R
Singapore GP
03 Oct
Next event in
211 days
10 Oct
Race in
221 days
R
United States GP
24 Oct
Race in
236 days
31 Oct
Race in
243 days
R
Australian GP
21 Nov
Race in
263 days
R
Saudi Arabia GP
05 Dec
Race in
278 days
R
Abu Dhabi GP
12 Dec
Race in
284 days

Mercedes: China double-stack was Wolff's idea

The original idea for the stacked pitstop for Valtteri Bottas and Lewis Hamilton in the Chinese Grand Prix came from Mercedes boss Toto Wolff, the team has revealed.

Mercedes: China double-stack was Wolff's idea

The Brackley-based outfit had been left with a strategy headache after Red Bull's decision to pit Max Verstappen for a second stop during the Shanghai race triggered a domino effect for the cars ahead to prevent being undercut.

With Sebastian Vettel responding to Verstappen's move, Mercedes knew that it too needed to cover Vettel with both its drivers who were running 1-2 on the track.

However, with Hamilton and Bottas running close together, if Mercedes had pitted Bottas first to head off the Vettel threat, then there was a risk that he could overtake Hamilton for the lead – which would have been unfair on the race leader.

Following a bit of quick thinking, Wolff himself came up with the suggestion of stacking the drivers in the pits, something that is rarely done during full race conditions.

After Wolff proposed the idea, team strategist James Vowles confirmed the plan would be tough but possible, before sporting director Ron Meadows gave it the green light.

Speaking on Mercedes' regular post-race YouTube debrief, the team's trackside 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."

Shovlin admitted that there were risks associated with the stop, especially because stacked stops are not something that can easily be practiced for.

"You don't have two cars to practice with," he explained. "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."

Such was the swiftness with Mercedes' procedures that Bottas' pitstop was actually quicker than Hamilton's – and he lost less than half a second in total pitlane compared to his teammate despite having to briefly wait.

Here, Motorsport.com reveal more details about how the stacked pitstop came about and the exact timings.

Valtteri Bottas, Mercedes AMG W10, makes a pit stop

Valtteri Bottas, Mercedes AMG W10, makes a pit stop

Photo by: Mark Sutton / Sutton Images

How Mercedes' double-stack stop played put

Lap 34

Max Verstappen pits for the second time, forcing the cars ahead of him to consider whether to stick to a one-stop strategy or move to a two-stop as well. At this stage, Mercedes it not sure if its tyres will last until the end if it stays on a one-stop.

Lap 35

As Hamilton exits Turn 14, the team begins the discussion the idea of a second stop to shadow the cars behind. But it faces a dilemma because second place Valtteri Bottas would need to stop first to protect his position to Sebastian Vettel if the German stops too. Doing that would then give the Finn the unfair advantage of the undercut on race leader Lewis Hamilton.

If the team pitted Hamilton first, though, then that would expose Bottas to the possibility of getting undercut by Vettel. Second latter, Toto Wolff from the garage suggests the unusual step of double stacking the cars. On the pitwall, head of strategy James Vowles says the tactic was tough but possible, while sporting director Ron Meadows confirms it is okay to do.

As the Mercedes drivers cross the start-finish line, Vettel pits: therefore prompting Mercedes in to action.

Lap 36

Just 22 seconds after the first discussion of a double stack, Vowles comes on the radio and says: "Going to do it now."

Both Mercedes drivers are told they are pitting, and Bottas is told about the stacking plan. The team and the Finn are both aware of the danger that Vettel poses if he is delayed in the pits. Coming into the pits, the gap between the two drivers is 5.5 seconds

Hamilton's pitstop takes 2.9 seconds, and his total pitlane time is 23.597 seconds. Bottas' pitstop takes just 2.6 seconds and his total pitlane time is 24.083 seconds. Measurements confirm that just 3.4 seconds after Hamilton moves away from his stop, Bottas stops in the same spot.

Lap 37

The swift turnaround of Bottas means he leaves the pits with a five-second advantage over Vettel, which is cut back to four seconds at the end of the lap when the Ferrari driver sets the fastest lap.

Lap 38

Bottas responds with the fastest lap of the race at that point.

shares
comments
Video: How F1's 2019 rule changes are mixing up every GP

Previous article

Video: How F1's 2019 rule changes are mixing up every GP

Next article

Verstappen targeting mid-season F1 race wins

Verstappen targeting mid-season F1 race wins
Load comments

About this article

Series Formula 1
Teams Mercedes
Author Jonathan Noble
Can Mercedes' W12 retain the team's crown? Prime

Can Mercedes' W12 retain the team's crown?

Replacing Formula 1's fastest car was never going to be an easy feat for Mercedes. Amid the technical rule tweaks to peg back the W12 and its 2021 rivals, the new Mercedes challenger will remain the target to beat

The pointed note that starts Ferrari's Leclerc vs Sainz era Prime

The pointed note that starts Ferrari's Leclerc vs Sainz era

Ferrari is starting its post-Sebastian Vettel age by welcoming Carlos Sainz in alongside Charles Leclerc. But while Sainz has a tough challenge to match his new teammate, Ferrari is also sending a message that previous intra-team spats must end

The mantra Ocon must follow to challenge Alonso at Alpine Prime

The mantra Ocon must follow to challenge Alonso at Alpine

OPINION: It's been an uneasy ride for Esteban Ocon since his F1 comeback - and fresh challenges lie in wait as he's joined by double world champion Fernando Alonso in the newly rebranded Alpine team. STUART CODLING sets out a roadmap to success…

Why Haas is willing to sacrifice its 2021 F1 season Prime

Why Haas is willing to sacrifice its 2021 F1 season

Every Formula 1 team is facing the same difficult decision this season: how do you split precious aero development time between the current car and the all-new 2022 project?

The big questions of F1 2021 - Karun Chandhok Prime

The big questions of F1 2021 - Karun Chandhok

After an unprecedented season last year, there are plenty of questions and storylines for the upcoming Formula 1 campaign. Sky Sports F1 pundit Karun Chandhok gives his verdict.

Formula 1
Mar 1, 2021
How McLaren F1’s new investors have already made an impact Prime

How McLaren F1’s new investors have already made an impact

The deal McLaren concluded with MSP Sports Capital last year which will help the cash-strapped Formula 1 team pay for much-needed infrastructure upgrades, also points toward the future for F1 itself, says GP Racing's Stuart Codling.

Formula 1
Feb 27, 2021
Why Verstappen isn't interested in the hype game Prime

Why Verstappen isn't interested in the hype game

In a pre-season where Red Bull has been unusually quiet, Max Verstappen has also been guarded about the team's fortunes in 2021. Even after trying the RB16B for the first time at Silverstone, the Dutchman was careful to manage expectations

Formula 1
Feb 26, 2021
The pros and cons of F1's 2021 rule changes Prime

The pros and cons of F1's 2021 rule changes

In the strategy for grand prix racing's future, 2021 represents a significant step towards the goal of closer racing and a more level playing field. That's the theory behind the latest raft of changes, but will they have the desired effect?

Formula 1
Feb 24, 2021