BMW Airbags Offer Head Protection

Understand components and operation of BMW's Head Protection System.


Understand components and operation of BMW's Head Protection System.

SUBJECT: Side Impact Airbags for Occupant Head Protection
TOPIC: BMW Head Protection System (HPS)
OBJECTIVE: Understand Components and Operation of BMW's Head Protection System
TASK: Develop Department SOG for operating at crash scene with deployed and 'loaded' BMW HPS

Rescue and extrication personnel are rapidly becoming aware of the increased presence of side-impact airbags in many vehicles. With over 34 models of 1998 vehicles having these systems, it will soon become the norm, not the exception, for responders to encounter side airbags at crash scenes.

Until the model year 1998, side-impact airbags had been designed to protect only the torsos of occupants during collisions. Now, the world's first head protection system is here. Introduced as standard equipment on the 1998 BMW 7 Series sedans built after June 1997, it is currently the only airbag system that helps protect the head of the driver and front-seat passenger during side-impact collisions. The BMW side impact Head Protection System( HPS) is also known by the acronym ITS or Inflatable Tubular Structure by its' manufacturer, Simula Automotive Safety Devices, Inc.

EMS responders realize how critical head protection is during side crashes. The Insurance Institute for Highway Safety (IIHS), a research and safety organization, states that one-third of all fatalities we see each year at crash scenes involve side-impacts. Statistics reveal that people killed in side crashes typically have a high incidence of head and neck injuries. Another IIHS study showed that 64 percent of occupants on the side of the collision and 82 percent of those seated opposite the impact side receive head injuries.

Until recently, side impact protection for occupants focused on reducing the degree of intrusion into the vehicle being struck. Reinforced door collision beams, improved door latches and padded interiors all work to cushion passengers during the impact. With the introduction of side impact airbags to the US market in Volvo's 1995 model year, the emphasis shifted to actively putting a cushion between the side of the vehicle and the occupant. Side impact airbags are specifically designed to protect the occupant's chest, abdomen, and pelvic region. Now we realize however, that even as side airbags deploy from doors or seats, the occupant's head and neck remain vulnerable to injury.

The HPS System

The new HPS tubular shaped airbag is specifically designed to protect and reduce injuries to the two body areas that are most vulnerable in side impacts, head and neck .

This author witnessed two 20 mile per hour side-impact crash test demonstrations where the forces on the head of the dummy went from being a fatal injury when no HPS was present to being a minor blow to the head of a dummy in an HPS-equipped BMW.

The main component of the new HPS system is an inflatable airbag tube.

This tube is anchored to the car structure at two points: at the front end to the bottom of the A-pillar ( bottom left of windshield window frame) and at the rear end to the roof headliner behind the B-pillar ( at the side of the roof behind the door frame).

The complete HPS airbag and the nylon straps sewn into each end of the bag is stowed inside the trim of the A-pillars and behind the headliner trim over each side window of the car. The HPS system, when 'loaded', is detectable only by the letters 'HPS' imbedded in the trim cover at the top of front A-pillars.

Located at the A-pillar end of the system is the gas generator. The canister which flows the nitrogen gas into the HPS airbag is located below the bottom of the A-pillar area inside the end of the firewall area in front of where the door hinges are located.

The HPS airbag is unlike any others that rescuers have ever encountered. The tubular bag consists of a specially designed material weaved in a pattern reminiscent of the Chinese finger toy where you put a finger in each end and pull apart.

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