Hamilton suffered pit stop woe in BahrainMcLaren's pit stop troubles in Bahrain last Sunday left one of their mechanics distraught after three errors in two races — but is it human error or over-complicated technology that's causing the problems?
Last year, Mercedes clocked in the fastest stationary stop time at just less than 2.5s and alongside Red Bull they were the standout performers in the pits with less than one hundredth of a second separating average stop speeds of the two teams over the entire season. McLaren was third best, just two tenths of a second slower on average.
This year, though, things have gone drastically wrong for McLaren — and several other teams have also been struggling to get to grips with the ever-increasing pace in the pits.
Since refuelling was banned and stop times became determined by the speed of a tyre change rather than the slow flow of fuel, pit stop technology has grown increasingly advanced as teams delve into the smallest of details trying to make every element of the stop a little bit smoother and a little bit faster.
And the balance between human efficiency and technology in pit stop equipment and car design is a delicate one.
In an F1 pit stop, each wheel has one person on the tyre and one on the wheel gun, with front and rear jack men to lift up the car and a chief mechanic controlling the whole process.
Just like a penalty shoot-out in football, selection is not simply down to who doesn't mind doing it — each team has a process to ensure the very best are picked for each exact job and that they are positioned in the right places to get the optimum team performance (in this case even being left- or right-handed can make a difference).
Constant analysis is done by video, timing and telemetry at every race, even down to on-person cameras on helmets, which give an interesting TV perspective but also show exactly what the wearer is looking at during the stop and how that affects the performance.
Each element is scrutinised, from the driver stopping the car in position through quick jacking and correct wheel gun operation all the way to the final release. It creates a crucial timeline. And when every human decision takes a split second, any mistake can see knock-on effects quickly compounded down the line.
That makes the driver the most crucial part — as he starts the process and needs to stop within a few inches of his marks to ensure the wheels are in the right place for the mechanics to do their job. Practice is crucial — and teams will do up to 100 trials during a Grand Prix weekend in set sessions to make sure they are match fit.
PIT STOP TECHNOLOGY
Teams have gone into a lot of detail to develop engineering solutions that aim to reduce human error - but it is getting the human element to work with the new complex but potentially temperamental technology where problems come.
Recent years have seen teams introduce automatic stop/go traffic light systems to release the cars, and these caused troubles early on — some enough to cause the teams to scrap them all together. Those who did persist with them have now engineered out the errors, and they gain a split-second advantage by using them instead of a person.
Gun attachment is perhaps the most vital part of the stop, and there are a number of different approaches on this.
Red Bull have used a laser system for lining the mechanics' hands up with the wheels, while most teams use bespoke wheel nut and gun designs to create a paired system with, in theory, the perfect edges and angles to make it easy to align gun to nut before the car has even stopped.
Mercedes has incorporated the wheel nut in the rim itself — so the nut cannot fall out of the gun in a stop, and in theory is guided on with the wheel to lock on more easily.
The jacks themselves have also recently been the subject of close attention. Anyone who has ever held and operated one will realise how powerful they are — the recoil and torque can really wreck your wrists — but Mercedes pushed the power further last year by introducing a helium system that made them spin even faster.
Many top teams followed, but it was banned this year, forcing teams to seek out other innovative solutions.
Some even have a gun for front wing adjustments now — pre-programmed with the amount of turns they need to make to move the flaps up or down, as altering the car set-up during a race is now even more important with the new tyres.
Some racing series have jacks integrated into the cars, but these are not allowed in F1 — but that has not stopped teams innovating in this area too.
Things have moved a long way on from the basic parcel trolley jacks once used. Now, teams have pivoting, swivelling trolleys made of carbon fibre, designed to spin so the jack man is out of the way when the car is released — rather than having to jump out the way as the eager driver puts his foot to the floor. Such technology is perfect when it works — but if a swivel locks at the most crucial moment, it can quickly turn into a disaster.
And that is the issue. With complex interlocking parts, built-in nuts, pins that need to spring out or pop in at the right time, there are plenty of techniques that can make that crucial difference — but there are also more elements of technology than ever that can go wrong.
And on occasions like China, when Jenson Button's wheel nut cross-threaded, or Bahrain, where Hamilton's wheel nut pegs failed to engage with the holes in the rim on his first stop and then a nut cross-threaded on his second, any mismatch between people and technology can suddenly turn out to be rather costly.