Analysis: Pitstops – How are they so quick?

This post was requested by email. Unfortunately I managed to delete the email so I can’t mention who asked for it! Apologies, but here it is for you…

At the US grand prix last year Red Bull performed a pitstop in 1.923 seconds, the fastest in F1 history. OK, that isn’t strictly true because as much as they like to brag about it, the car was stationary for 1.923 seconds. The actual pitstop time is recorded from the moment the car enters the pitbox to when it leaves the pitbox. FOM place timing gates at these points and this is the time we see on our screens. So really, considering a driver’s reaction time to the green light is about 0.2 seconds and it takes a couple more tenths to get in and out of the pitbox, you’re probably looking at an overall time of 2.2-2.3 seconds. Impressive.

Red Bull – and all of the top teams at least – can measure the stationary time of their car using cameras placed on the boom(s) of the pitbox, hence why they were able to proudly announce their ‘world record’.

Now that we’ve mentioned it, let’s start with the boom. In lower formulae and GT racing, teams will have one boom to accommodate the hoses for the pneumatic wheel guns so the crew on the opposite side of the car away from the garage don’t have to loop it over the car and cause a bit of a mess.

The two booms are pivotal to reducing pitstop time. (Image: redbull.com)

The two booms are pivotal to reducing pitstop time. (Image: redbull.com)

In F1 the teams have a full pitcrew and it gets a bit crowded so teams use two booms – one for the front wheel gun and one for the rear wheel gun.The booms are also the mounting points for the traffic light system and, as highlighted in the image above, the aforementioned cameras. The cameras are used to observe other details which can be analysed by the team before making changes to improve the efficiency of the ‘stop.

Now that we know the function of the booms, we can delve into the role of each member of the 18 (although there are 21 in total ready for action) man pit crew and what equipment they have on them.

Purple = jackmen; Yellow = wheel gun; Light green = wheel off; Orange = wheel on; Dark green = front wing adjust; White = additional servicemen. (Image: allaboutlean.com)

Purple = jack men; Yellow = wheel gun; Light green = wheel off; Orange = wheel on; Dark green = front wing servicemen; White = additional servicemen. (Image: allaboutlean.com, edited by theWPTformula)

Front jack man

The best place to start is from the front where we have the front jack man plus a reserve jack man ready with his jack if needed. The front jack is a very advanced piece of kit these days with many teams investing in carbon fibre construction, high end mountain bike parts and pivoting mechanisms in order to create the fastest car lifting device in the world. Depending on the height and preferences of the front jack man, he can even choose the handlebar’s width and rise to suit his leverage capabilities.

To help the driver slot into the centre of the pitbox, the front jack man will line up the jack on a marker as the car enters the pitbox whilst the driver picks his spot with the help of a large (and often fluorescent) arrow pointing downwards on the jack itself. The entire length of the arrow is often in the driver’s eyeline so he can place the nose as carefully as possible to the middle of the pitbox.

Once the car is up (with the aid of the rear jack man) the front jack man can then move to the side of the car using the pivot mechanism installed. The lift pad and wheels of the jack are independent of the upper section which is allowed to freely rotate around a pivot. Typically the jack pivots along a horseshoe-shaped track rather than aimlessly through the air to keep things smooth. As he moves to the side of the car the jack man holds a mechanically linked lever (mountain bike mechanical brake levers are used), which maintains the lifting pad’s position, as he waits for the car to be serviced. Once the new tyres have been fitted the jack man releases the lever so the front of the car is free to drop, before pulling the jack out of the way as the car exits the pitbox.

Rear jack man

At the same time, the rear jack man has to be perfectly in sync. His jack is not as fancy as his front man’s counterpart but they still feature a release mechanism (rather than pushing up on the jack and wasting fractions of a second) and are often made from either aluminium or carbon fibre.

The rear jack man’s job is a little trickier as he has to run in as the car enters the pitbox and scoop up the rear of the car from the underside of the rear crash structure – just behind the rain light. In years gone by a small hook would hang beneath the rear crash structure for the jack to latch on to but, to save time, the lifting pad on the rear jack is now a moulded piece of carbon fibre that is shaped around the crash structure, with only a small stop to prevent the lifting pad from going too far towards the front of the car. 

Wheel men

The wheel gun man’s job is simple but very difficult to perfect. He has to track the car into the pitbox and get the gun onto the wheelnut even before the car is completely to a hault. He also has to follow the new wheel on as closely as possible so he can instantly start tightening the nut. Two trigger pulls and a reverse torque change to his gun later he can then breathe a sigh of relief. And this is when the car has stopped on its marks.

The driver is tasked to line the car up in the middle of the pitbox and on the marks provided to ensure that the mechanics don’t have to move position in order to perform their pitstop. If the driver brakes too early he will often stop before his marks, shuffling everyone backwards. However because they often come barreling in at full pelt, most drivers tend to overshoot their marks (sometimes by as much as 10 centimetres) so everyone has to shuffle forwards. 

The wheel gun man always has a spare gun plus a spare nut in case of a disaster. I’m not sure how difficult it is to cross thread an F1 wheelnut but I’d be terrified of messing it up!

The wheel off man acts as another guide for the driver on the way into the pitbox as he either has a board or a fluorescent back to his glove which he holds above the marks at the height of the wheel. This allows the driver to brake closer to his marks as he can align the tops of the tyres (the only visible part of the wheels the driver can see) with the board/glove. The wheel off man then moves on to dispatching the old tyre, pulling the wheel off as the wheel gun goes to work. Once he has dumped the old tyre he can then get on to checking the brake ducts for debris.

Getting the next tyre on is tricky and timing is crucial. Three people around one wheel must be difficult to choreograph, which is why they spend so much time practicing. The wheel on man has to get the new tyre on as soon as the last part of the outgoing wheel is clear, squeezing in front of the wheel gun man in the process. It’s fiddly, especially in all their gear, but that’s why they are paid to do it as part of their job.

Additional servicemen

These guys will often check the sidepods and bargeboard area for any debris or marbles that intervene with the airflow. This is after they have helped the jack men by grabbing inside of the sidepod inlet and airbox and hoisting the car up more speedily. It is the masses of small details which reduce chunks of time and these two men are two more pieces in the puzzle.

Front wing servicemen

The two men at the front of the car have three tools to service the car for any of three scenarios – a front wing flap adjust, cleaning slot gaps or replacing the entire nose/front wing assembly. The flaps are adjusted using a small drill which slots into a tiny pod on the front wing.

The drill’s trigger is preset to the equivalent of, say, 1 degree, so one trigger pull is one degree of front wing – one turn. The driver can request as many turns of front wing as they like, up or down (unless they are already running maximum or minimum wing angle), for their pitstop although they often have a set strategy during the race as the fuel load comes down and the balance of the car changes.

Small brushes are used to clear any debris (often marbles) from the front wing’s slot gaps, as these allow consistent front downforce to be generated across a large speed threshold. 

To change the nose, the front wing servicemen carry an Allen key of some description which can free the front wing assembly from the chassis, ready for a new one to replace it with.

All done?

Once all four tyres have been replaced the car is dropped and one from each of the wheel crew raises his arm to confirm that their task is complete. A man overlooking the entire pitstop stands in front of the car with a view of the pitlane holding a switchboard. He can then release the car via the traffic light system if it is safe to do so or he can even change it back to red if there is a problem.

Past traffic light systems have had their glitches... (Image: singaporegrandprixf1.com)

Past traffic light systems have had their glitches… (Image: singaporegrandprixf1.com)

In years gone by each jack man and wheel gun man had a button that, when everyone had pressed, would automatically cue the green light. However after a series of unsafe releases this was changed to the aforementioned system on safety grounds, and to be honest it probably works better as the mechanics can focus on their job properly rather than rushing to press a button.

It is then up to the driver to react to the lights to complete the pitstop.

Analysis: The good and not-so-good of each car – Part 2

This is part 2 of the post requested by @robb___alexander on Twitter.

In the first part of this analysis we took a look at the top teams’ technical features. For this second installment we will look at the remainder of the grid including the intriguing Toro Rosso STR9 and just how Williams’s FW36 has recaptured their form.

Force India VJM07

+ Force India continue to design a car that is kind on its tyres. It’s a design feature that has been prominent ever since the current regulations’ inception in 2009 and it is unclear whether it has been a deliberate philosophy or a handy characteristic of their platform. It sets the team back in qualifying trim but their ability to push during the race has seen them score in every round this year bar Hungary. With a good haul of upgrades during the Austrian and British GP period plus a few more on the way, the VJM07 once again punches well above its weight in the battle against McLaren.

Despite having significantly less money to play with than the surrounding competition, Force India continue to develop their strong 2014 contender

Despite having significantly less money to play with than the surrounding competition, Force India continue to develop their strong 2014 contender

- Qualifying pace and generally lacking a bit of downforce. This is where a smaller budget can cost a team such as Force India as their creative solutions (they were one of the first teams to start packaging the sidepod area more tightly this year) can be met and then overcome by bigger spenders. Keeping up the development pace is tough but the car is extremely consistent, so they have no major worries.

Sauber C33

+ It started the year overweight but the team have worked hard to bring it down to near the minimum (690kg) and take advantage of their Ferrari power unit by significantly pinching in the bodywork from Spain onwards.

- It is sad to say that there isn’t much good about this year’s C33! Not only is it still a touch heavy but it is visibly appalling to drive in any conditions at any circuit. This is primarily down to Sauber’s brake-by-wire (BBW) system, which delivers a very inconsistent feel to the driver even from lap to lap. Adrian Sutil described it as a different car to drive every lap, which brings us back to having confidence in the car as mentioned in part 1.

Sauber’s power unit (PU) is supplied by Ferrari so that means that they also receive their MGU-K, which harvests under braking. I can only have an estimated guess that the BBW system isn’t calibrated to enough types of braking/harvesting events, hence why it tends to grab at the brakes or not work at all. This could even boil down to the initial braking phase and the way Sauber are choosing to harvest their energy. It’s a complex area and until it is fully fixed the team will be going nowhere.

Toro Rosso STR9

+ The STR9 is quite possibly one of the most intriguing cars of the year. It is quite simplistic in the sense that there is nothing too standout about it in terms of complexity. However it is the culmination of the finer details that perhaps make it the best Renault-powered car after Red Bull. Aerodynamically the car looks pretty sound and, like every Toro Rosso since its birth, is pretty hand in the wet.

The ugly but neat airbox layout – which provides the ICE with forced induction air and cooling for the gearbox oil – removes volume from the sidepod area and allows a slimmer engine cover further behind. I am still a huge fan of the floor-mounted rear wing endplates as although it adds a bit of weight it reduces drag and manages the airflow around the rear tyre. 

The STR9 may look simplistic but it's an almost-perfect benchmark for the likes of Daniil Kvyat to hone is skills

The STR9 may look simplistic but it’s an almost-perfect benchmark for the likes of Daniil Kvyat to hone is skills

 – As technical director James Key pointed out earlier this week, reliability has been a bit of a shambles. Failures have been dotted around the car including exhausts (not made by Renault and on two differing occasions), rear track rods, brakes, gearbox and the PU itself. It is unlikely that they will catch the McLaren-Force India battle but as long as the cash keeps pumping in from Red Bull owner Dietrich Mateschitz then they shouldn’t have to worry.

Williams FW36

+ A combination of fortune and Pat Symonds’s guidance have seen Williams ascend to the podium on a regular basis once more. No “top” designers have been employed since the dark days of 2011 and 2013, just a slight restructuring and a little encouragement have led to solid car which just so happens to have a Mercedes engine in the back. The FW36 is quite slippery whilst creating very useable downforce, so we often see the Williams drivers at the head of the speed trap standings. The team have also taken a massive advantage from their unique short gear ratios (as discussed here) to propel them off the line and defend during the latter stages of races. Having been the only car other than a Mercedes on pole position this year, it’s been a damn good year for the team so far.

- Although rear tyre degradation has been cured to a certain extent this year, you could argue the fixes have set them back a little in pace. This is similar to what happened with Mercedes in 2013, so you can bet that the fundamental problems will be addressed for 2015. 

Marussia MR03

+ Marussia have honestly created one of the best cars on the grid this year given their budget. Perhaps the key to unlocking their form and challenging the other midfield teams was the switch to Ferrari power but look at how poorly Sauber are doing. Marussia, along with McLaren, were the initial users of the ‘Y-lon’ central rear wing pylon/Y100 winglet mount. This was coupled with the keel nose design, something only Red Bull had really considered. The continuous upgrades show a good thought process going into the MR03 so hopefully they can kick on from here…

- Although steps have been made to address the issue over the past couple of years (they have a technical partnership with McLaren), the MR03 still doesn’t have the downforce to consistently reach Q2. This is mostly down to their reliance on CFD over wind tunnel resources as the team continue to operate on the lowest budget on the grid.

Caterham CT04

+ There are a few positive things to say about the CT04, the biggest plus being that funds have been found to produce a large upgrade for Spa this weekend. The fundamentals of the car are based on reliability as their lack of knowledge surrounding the Renault PU is clear to see by the large sidepods (particularly the massive outlets which allow viewers to take a nice look at the gearbox case) and basic aerodynamic features.

- The biggest downside of the CT04 has, like Sauber, been its BBW system. The thing that makes it harder for the team is the car’s lack of downforce, so the driver really is struggling to get the car stopped properly. Their issues are not quite so deep as Sauber’s but they are certainly a hindrance, particularly to rookie driver Marcus Ericsson who has looked a bit out of depth so far this year. Confidence is key and if they can give that to the drivers they might be able to claw back at Marussia’s slight advantage.

Announcements 2…

As we all know, the summer break is nearly over (about time) so I shall be finishing this last week with part 2 of my latest post, an email requested post and whatever else I think of.

Secondly, I’ve already told you via social media but I’ve got a place at Swansea University to study Mechanical Engineering with a year in industry! I’m really excited to go and I’ll be able to translate what I learn into my posts on here, so we’re all winning.

Things can only go up on this blog and I thank you all for continuing to visit!

Analysis: The good and not-so-good of each car – Part 1

This post was requested by @robb___alexander on Twitter. I have another post coming up that was asked for via email so please get in touch and I’ll see what I can do as the summer break continues.

To say that a car has a “bad” feature would be incorrect – it’s rare that a team designs something bad. No team designs something bad because they have the data to tell them that it isn’t. However, there is a competitive order so clearly some cars have worse features than the top guys. In this piece I aim to dissect each car and pick a few plus a minor points from them.

Changing the minor points will not necessarily make the car quicker because it is all about the complete package. Take Mercedes as an example: if their power unit is so good, why do the manufacturer team still have such an advantage over the likes of Williams and McLaren? Their car overall is the performance benchmark and it is composed of a number of technical solutions that make it one of the most dominant cars in the sport’s history. Continue reading

Link: Mid-season tech review

2014 mid season

I have done a mid-season tech review for Richland F1, looking at how the cars have evolved so far this season using my updated 2014 design drawing above. You can find the article here.

I have got some more requests coming up over the next two weeks. If you want something explaining in a blog post format, do share it with me either on Twitter, Facebook or email (see the ‘About‘ section for my address). Thanks!

Analysis: Gear ratio selection

This post was requested by @cditman. If you would like something explaining or have an questions please contact me either on Twitter, Facebook or email – thewptformula@gmail.com. Cheers!

gears

As of the start of the 2014 season, teams must nominate all 8 forward ratios (plus reverse) before the opening round. They then have only one opportunity, should they be willing to take it, to change their ratios during the season. That’s it. No bespoke gearing for each track and no free-spirited changing during a Grand Prix weekend.

Given all the computer, dyno and simulation technology at the F1 teams’ disposal, it’s quite amazing how varied the ratio selection is across the grid. There are some positive and negatives for each solution, but is there an optimum setup?

At the midway point in the season, I’m going to attempt to dissect some of the teams’ gear ratio choices and why, surprisingly, they have not converged to one solution. Continue reading

2014 Hungarian GP Tech Highlights

The final round before the 4 week summer break was held in Hungary – a very high downforce orientated circuit with only one straight to worry about in terms of drag reduction. It is for this reason that we often see as many aero bits crammed onto the cars as possible, just like Monaco.

Straightline speed is not a necessity but strong driveability is crucial for good laptime, from both the power unit and the chassis. This is particularly notable in the middle sector where a series of medium speed corners really test the car’s aerodynamic balance and power delivery. This is why Red Bull appeared to be a step closer to Mercedes as their chassis is arguably the best on the grid and their Renault power unit has had multiple software upgrades on the driveability front.

As far as new tech went there wasn’t much to talk about but as always there were a few things that are worth mentioning… Continue reading