by Alain Hoffmann
Rollcage tech - part 1
Rollcages and -bars are mandatory on many off road events but I would recommend them even for 'normal' Land Rovers who see greenlanes only from time to time. Most accidents occur on roads and it's not uncommon to see an Rover rolling on or over it's top.
As the roll-over protection is not yet regulated by law it leaves much to desire. Did you ever wonder why Land Rover fitted the expensive rollcages made by Safety Devices to their NAS-specs Defenders? Well, it's because this protection is required in the US.
Discoveries and Range Rovers do seem to survive a roll quite well. (above: This Rangie was overturned by another car that hit him from behind. It flew 5 metres through the air). Usually the A-posts deform and absorb energy wile the B-posts behind the front seats keeps up the weight and the metal roof prevents a binding backward. At least the energy is much better absorbed. Below: This rangie turned over at about 80 km/h together with his trailer loaded with a Ferrari.
Defenders as well as Series vehicles are much more dangerous in a roll.
This Defender above from South Africa slid on spilled diesel, went off the road and turned over several times. The 2 occupants escaped with some cuts and a few broken bones. But look at the upper structure of the body. All the roof crumpled down and had to be cut by the SAR team. This car even had the heavy roofrack mounted (a corner is still visible in the lower right edge) which spread the impact evenly.
This army XD Wolf had about the same fate but it wore an rollcage as standard with the modern army version. Look how the impact energy was absorbed and tranfered to the supporting structure instead of the body. The front screen was removed by the SAR team probably to facilitate the evacuation of the driver.
Above: Compare the 2 cabs. I think the pictures say enough. Look at the headrest in the right picture.
And another picture now of an D90 NAS WITH the full Safety Devices Rollcage.
This one belongs to Ben from the USA. One moment of distraction while climbing the rock in the background sent his white Rover over the top and backwards. The rollcage did it's job and spread the load. The front collapsed but the loop behind the seats hold up and protected the occupants when the car hit the massive stone.