As a result, these load paths were significantly reinforced by using high strength HSS 2 steel and increasing the rocker height by 35mm. The load path through the door structure can carry loads up to seven tons - comparable with the cumulated load capability of a Focus 4-door at the roof and door structures.

Despite high levels of impact energy passing through the door structure, the load path results in no mechanical pressure to the door lock. Crash energy is distributed via the upper door reinforcement structure and into the rear side panel. Door structure shut faces have a profile narrowing by seven degrees, which avoids canting after a crash and supports easy opening.

These highly effective stiffening measures yield tangible results. During standard side-impact crash tests at 50kph, deformation of the passenger cabin's side structure measured at the B-pillar was around half of what a comparable sedan delivers. Injuries related to head rotation are mitigated due to the complete lack of an upper B-pillar.

Crash tests with the optimised rear body structure have been carried out to Ford's standard rear impact speed of 80kph. The structure performs well even with the car in Cabriolet mode. When folded away, the hardtop segments act as additional elements that can deform in the event of an impact, while the highly rigid rear bulkhead together with the lowered RPD (Rollover Protection Device) bars form an effective anti-intrusion guard for the passenger cabin area.



Rollover Protection Device (RPD)

In addition to standard front and side airbags, Ford's new RPD system plays a vital role in increasing Focus Coupe-Cabriolet's passive safety performance.

RPD is designed to help protect passengers in the unlikely event that the vehicle rolls over. Electronic sensors and a gyroscope are at the heart of the system, and can detect an impending rollover. When this happens, two ultra-strong safety roll bars "fire" into position within a tenth of a second. A pyrotechnic device unlocks the system, then extremely strong springs force the roll bars upwards to their deployed position where they lock safely. The bars move up by approximately 20 centimetres to provide an ideally positioned safety strut. When the car has its roof up in Coupe mode, they can also deploy. Combined with the reinforced A-pillars and the highly rigid front window frame, RPD is a reassuring device that provides valuable extra protection for occupants.

While it was important to calibrate the RPD system settings so that the safety roll bars deploy quickly and before a potential rollover, it was equally important to eliminate the possibility of unwanted ignition.

Dirk van Oirschot, Project Manager for Safety, says: "The calibration setup was developed "virtually", using detailed calculation models on powerful computer system models. Subsequently, however, we tested and evaluated the system calibration meticulously and in a wide range of test conditions, reflecting almost any potential real life situation."

Three-point safety belts for all seats with pretensioners and load-limiters for both front seats, the well-proven Ford horizontally stroking steering column, and safety pedals all combine with RPD to maximise occupant restraint and protection.

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