Topless Wonder

This spring, when Volvo Cars begins selling its second-generation C70 convertible, the 4-seater will feature advanced active and passive safety systems that combine to produce a high degree of occupant protection, despite the absence of a fixed roof much of the time.

“It is a major challenge, but today we know considerably more about safety in convertibles than we did with the first C70,” says Ingrid Skogsmo, who oversees Volvo Car's safety center in Sweden.

“We know the type of accident a convertible is exposed to and how protection should be built up around the passengers,” she says. “Our aim was that (the car) should have the same effective side impact protection as the Volvo sedans.”

Volvo revised its Side Impact Protection System to be effective for a convertible. The retractable hardtop folds down in three pieces.

In a sedan, collision forces are spread into the roof structure, something not possible in the C70.

Instead, the SIPS system channels crash forces forward, backward and downward into the body structure. An integrated system of members and reinforcements is used to preserve the integrity of the passenger compartment.

Volvo says the all-new C70 is twice as torsionally rigid as the previous model, thanks to the reinforced body structure.

Extra reinforcement is employed in the B-pillars that are linked through a transverse floor member. In all, there are five transverse members along the length of the C70. A flexible deformation box between the B-pillars and the transverse members also absorbs collision forces.

Doors have been strengthened to prevent intrusion into the cabin. They hook onto the B-pillars and remain closed when subjected to collision forces. The C70 has door-mounted inflatable side curtains and seatbelt pre-tensioners for all seats.

When activated, the side curtain deploys upwards. The curtain has double rows of slats that make it extra stiff and allow it to stay upright for effective head protection even with an open window.

The curtain stays inflated longer than a frontal airbag and deflates slowly to provide protection in the event of a rollover.

The C70 also features a rollover protection system. Powerful metal bars deploy behind the rear-seat passengers in the event of a rollover. The bars are stronger than the ones used in the original C70 and are activated by a pyrotechnic charge to deploy quicker.

The bars are equipped with small, hard metal spikes in order to push through the glass rear window if the roof is up.

Other safety features are designed to mitigate rear-end collisions. There also is a whiplash protection system to further guard passengers in rear-end collisions. Backrests and head restraints in the front seats follow the movement of the occupant's body.

The exterior of the car has been designed to reduce injury to pedestrians and cyclists.

Assembling the C70 for Volvo is Pininfarina SpA, the Italian specialty car builder and design house, at the Pininfarina Sverige AB factory in Uddevalla, Sweden.

Volvo and Pininfarina formed the Pininfarina Sverige AB joint venture to handle the C70 project. Pininfarina owns 60% of the JV.

Volvo unveiled the C70 convertible at the 2005 Frankfurt auto show, and the auto maker expects about 16,000 to be assembled annually. U.S. deliveries are expected by late spring.