In Detail: F1 seats

Formula1 is often about setting a car up to suit the needs of the driver, but there can be no part more intimately linked to the driver than the seat.  Literally moulded to their shape, the modern seat is a far more complex piece of engineering than the foam moulded seat used in the old days.

Made from carbon fibre the seat is custom-made to fit the driver and the cockpit.  Each driver prefers their own shape and features.  Often the sides and bolsters are differing shape for differing drivers; Jenson Buttons seats at BAR & Honda were almost wrapped around his torso, as well as an additional bolster formed in the front of the seat between the driver’s thighs.  Regardless of the drivers preferences the process to make an F1 seat starts with the classic seat fitting.  The driver will arrive at the factory and switch into their overalls; they will sit on top of robust plastic bags fitted loosely in the empty tub.  With the chassis already set up for the driver’s steering wheel and pedal position, their seated position will form the outline of the finished seat.  The bags will be filled with either foam beads or two pack expanding foam.  The bags will fit the contours of the driver and the internal shape of the tub.

Copyright: Caterham F1

Often we drivers have seat fittings completed in older chassis; it’s a surprising fact that as much as the rules alter every year and the cars end up being 90% new, the insides of the cockpit are quite tightly regulated and the basic dimensions do not alter from year to year.

The rear of Neel Jani’s seat

In this article I refer to a seat which I own, that was made to fit Driver Neel Jani into a Jaguar R5, when he tested for the team at the point Red Bull took over the Milton Keynes based operation.  Despite the nine years between it being made and today, I suspect it would fit any current cockpit without much trouble.

Whereas in previous times this foam would have gone on to form the final seat or at least had a mould taken from it, nowadays the process goes a little more high tech.  The foam buck is scanned into 3D CAD software, the point cloud taken from the seat buck is then smoothed into a finished surface in the CAD software the areas which the driver does not contact, are removed and the seat tidied into the final shape, complete with the various flanges and details to make it fit neatly into the monocoque.  Some Drivers will have an indentation made into the seats surface along where their spine sits to accommodate extra padding.

This a link to a feature that shows more about the 3D scanning of parts in CAD and the source of the two pictures linked below

A scan of a foam seat mould (Copyright Elysium)

The finished seat design (Copyright Elysium)

As part of the rules the seat now is required to have several rescue features built into it.  This include six straps to assist lifting the driver out of the car while still in the seat, as well a section to allow the fitting of the neck brace to hold their neckspine steady during removal from the cockpit. Thus the seat has to be sufficiently strong to support the driver’s weight (~65kg) during removal, teams are not allowed to fit vestigial or two part seat, the seat must reach from the driver’s shoulders to the back of their knees.

A Sahara Force India Seat – showing the straps to aid extraction (Copyright – Memento Exclusives)

Once the 3D model is complete, the data is used to 5-axis machine a mould from tooling block.  This is then used to lay up the carbon fibre.  The seat mould is a male part, so that the driver sits on the smoothly moulded face of the seat.  The thin pre-preg carbon plies are strengthened by a honeycomb layer across most of its shape and then a thinner layer of carbon fibre.  Thus the outer face of the seat is less tidy, but is rarely seen and often coated with heat reflective material to reduce the heat stress on the driver from the electrical equipment and heat coming up through the floor from friction of the car ground out on track.

The underside of the seat showing the honeycomb core and the heat reflective material

Some teams upholster the seat, to suit their corporate image, the material and padding is thin as the driver is strapped so tightly into the seat, any excessive padding would allow the driver to move under high G-forces.  The driver will sort out the finer points of seat comfort at the first tests, with small pieces of padding or even Duct tape being added to refine the shape.  These will be either permanent additions or the seat mould may be revised. It’s normal for the driver not then to make any seat modifications through the season and only a few seats will be made for each driver.

My Jani seat that I have is un-upholstered, it weighs in at just 2.25kg, and no doubt current designs are even lighter, as the teams refine the design.

One exception has been Michael Schumacher who used inflatable cushions to tune his seat comfort through the weekend. As explained here.

The drivers seating position is partly dictated by the height of the helmet projecting from the cockpit, the top of the helmet must not pass through a line projected between the front and rear roll hoops.  Some drivers sit higher or lower below this limit, based on their overall height and their ability to see clearly over the front of the chassis.  As the drivers should will be somewhere between 450-500mm above the floor, the driver is steeply reclined.  On the Jani seat, the drivers bum sits in a 200mm flat section spaced some 400mm from the back of the driver’s shoulders.  Also with the raised moncooques favoured by all teams, the driver’s feet sit well above the floor.  Jani’s knees were some 250mm above the floor.  Currently driver’s feet could be some 370mm above the floor.  As odd as this sound the resulting seat is very comfortable and the position feels natural.  I have never met Neel Jani in person, but I fit quite easily into his seat, I know other driver’s seats are far tighter and most of us fully grown adults would not fit into some of the smaller drivers seats.  The myth that F1 cockpits are cramped is not justified.  The shoulder area is mandated to be some 520mm wide as a minimum, but the monocoque is far wider internally than this making space for wide shouldered or hipped drivers.  Equally the reach to the steering wheel and the pedals is set out in the rules, meaning taller drivers are not unduly handicapped in fitting into the car.

I’m often asked if a seat or bare F1 monocoque would make a good gaming set up, as most people contacting me feel they would not fit.  But as explained both would be ideal for most adults, unless the seat was for a particularly small driver.  So a monocoque or even just a seat would add the real F1 experience to a gaming set up.