Sitting off a roundabout outside Andover is the UK headquarters of Britax. The company is all about car safety, and having merged with German counterpart Römer in 1979, has been making child car seats for more than 40 years.

Housed on the Hampshire site is its own crash testing facility and as it is Child Safety Week (18-24 June 2012), we decided to drop in and see exactly what goes on in the innocuous-looking building.

Crash testing plays and important part in the design of all aspects of vehicles these days and for good reason. In the case of child car seats, the European Test Standard covering child restraints is known as R44. We're introduced to R44 as soon as we step into Britax's test facility. 

Surpassing standards

R44 may be the framework for car seat testing, but it's only a first step - something that becomes clear immediately as Andy Whiteway, one of the team of staff at the Britax crash test facility, points out the two setups there.

The smaller is for testing R44 specifically, but a much larger rig is in place to carry out more dynamic tests. "R44 is a good starting point," Whiteway explains, but Britax takes things further. 

The R44 test rig

The large crash test rig is air powered and will let Britax run tests at up to 90G, but typically tests are carried out at around 31G. The rig allows frontal and side impact testing, using a car shell mounted on a sled.

It's an impressive, if rather raw-looking fusion of steel, bolts and concrete. The forces involved mean that the decellerator (the final point where the speeding sled is stopped) couldn't just be bolted to the floor. On installation, about 6 metres was excavated beneath the decellerator to be filled with a reinforced concrete base, damped with silicone. 

This means that when the sled-mounted car body is slammed into the decellerator, the whole thing doesn't tear the floor up or shake the buildings next door. 

The VW Golf on Britax's crash test rig

The car shell being used is a VW Golf Mk IV. Other car bodies can be used, and car manufacturers can use the rig to test seats, and often do. In many cases Britax is the recommended brand from car companies including the likes of Bentley, which encase the seats in matching interior leather for the luxury marque.

The crash test rig involves some expensive equipment. Fortunately there is no need to destroy a car as with the classic Euro Ncap frontal testing, but the principals are similar. It's all about energy and what happens to that energy on impact. 

Whiteway explains: "That car body weighs nearly half a tonne, that becomes nearly 16 tonnes at the point of impact," before detailing that the energy has to go somewhere. The point of a child seat is not just about restraint of the child, it's about dissipating some of the impact energy through the seat and not directly into the child. 

Dummies pay the price

Central to testing are the dummies. These aren't just human size and weight models, they are pieces of scientific measuring equipment. The older dummies, known as the P series, cost around £12,000 each. They offer six channels of data output to record forces acting on the dummy during the tests.

The new Q series, however, offers 27 channels of data. The dummies cost around £60,000 each, so kitting out your crash test facility with a typical family is an expensive business, but you can get a range of sizes to reflect different child ages.

And that's before you get to the monitoring and data collection equipment. In the rear of the car shell on the sled is data acquisition unit, which collects the raw data from all the different channels involved in the crash. This unit alone costs about £80,000.

Then you have camera for video capture. Although digital video capture has come an incredibly long way recently, you're still looking at around £15,000 for each camera. Britax use seven or eight cameras to capture the crash, recording at 1,000fps. In this case it's the IDT MotionXtra N3 slow-motion camera.

The classic crash test dummy target, the black and white quartered roundel, enables software to track the movement of a particular point. This means that Britax can specifically track the movement of a child's head on video, for example, as well as collecting the data from the accellerometers and so on within the dummy. 

Testing is something that Britax is taking seriously, and not just to satisfy the regulations stipulated by R44. "All car seats pass the same standard, but some surpass it by much more," says Dominic Goodwin, product trainer at Britax.

In the hot seat

We witness the testing of Britax's latest models of car seat: the Trifix and the Baby-Safe plus SHR II. The names might be funny, but there is a lot that's gone into the development of these seats. The Trifix, the newest and safest seat Britax has produced to date, has more than £1m in development behind it.

The name comes from the three fixing points it provides, using the ISOFIX system that Britax helped pioneer with VW in 1997, and a top tether point, allowing a third point of attachment. 

The Trifix (front), Baby-Safe plus SHR II (rear)

Goodwin talks us though some of the considerations when choosing a car seat. Formerly with Mothercare, Goodwin isn't making a hard sell of Britax products: "It's not about having the best-rated car and the best-rated seat," he explains. "They have to work together."

This is one of the biggest problems: many people make their decision based on design, colour and convenience, not necessarily on safety features and fit. Repeatedly he tells us that the right seat for the car and the customer is the number one priority, regardless of the brand.

Correct fitting is a huge problem, with Goodwin relating tales of checking 55 cars in a day and finding only two with correctly installed seats. Naturally, Goodwin is a huge fan of ISOFIX, because it makes fitting so much easier.

To help Britax owners, seats now offer a QR code, which you can scan with your smartphone, to take you though to a demo video so you can see how to fit your model of seat, without having to use a DVD or paper manual.

His final advice is this: don't buy second hand, make sure you buy the right seat for your car and don't be in a rush to move your child "up" to the next size. If you've paid £160 for a seat, leave your child in it until they need to move up, not as soon as they hit the minimum weight for the next step.

A lot more goes into car seat design and testing than we'd considered and having seen some of the crash testing in action, making the decision about what your child sits in from 0-12 years should perhaps get a little more of your attention.