Part Two of this series picks up where we left off last issue, back at the January 2003 North American International Auto Show in Detroit. With more than 700 vehicles on display in one building (and a similar number of changes in vehicle design, technology and safety features), it's very difficult to report on everything I saw that pertained to the fire service. (That, and the fact that I don't want to bore the snot out of you, either.) First, let's take a look at an awesome new hot rod, the 2004 Cadillac XLR sports car. The XLR is really nice-a very neat car constructed of material similar to the Corvette's. It's also built on a Corvette frame structure. However, you shouldn't confuse the two cars, because the XLR is definitely a Cadillac. (As you can see in Photo 1.)

Photo 1: It may be as sporty as a 'Vette, but the new XLR is all Cadillac.

A composite material identical to that found in the 2004 Corvette surrounds the hydro-formed perimeter frame. An aluminum cockpit frame surrounds a structural center tunnel. All of the core material is made of a high-strength substance designed to withstand high-speed crashes. The body itself has composite material body panels identical to the Corvette. In fact, the XLR will even be built at the same plant as the Corvette, in Bowling Green, Ky. (Diagram 1 depicts the XLR's space frame structure under the composite material panels.)

Diagram 1: The XLR's space frame structure lies beneath its composite material panels. All core material is designed to withstand high-speed impact.

The XLR is a two-seater with a retractable hardtop that converts the car from coupe to open roadster in less than 30 seconds. The top on the XLR is installed as a complete unit and adds greatly to the rigidity of the car. The roof structure is made of an aluminum-magnesium frame encased with composite material external panels and solid glass in the back with permanently mounted rear quarter windows, all contributing to the strength of the roof structure. All in all, this is a design that is much different from that of most convertible cars.

An electro-hydraulic system operates the folding roof mechanisms and controls eight hydraulic cylinders to retract the roof below the surface of the vehicle. When retracted, the roof is completely packed away into the trunk area and invisible to the eye.

Having the roof in the "up" position could present quite a few challenges to rescuers, who will have to cut through high-strength alloys of aluminum and magnesium. I personally haven't had the opportunity to cut on one of these cars yet, but you can bet I'll be the first one in line when the time comes. With eight hydraulic cylinders operating the roof, the rescuer runs the risk of cutting through one of these cylinders, especially if he can't see what's on the underside of his cutter.

I have some other concerns about the XLR, such as what might happen if the vehicle becomes involved in a fire. The possibility exists for the car's hydraulic cylinders to become pressurized and subject to BLEVE (Boiling Liquid Expanding Vapor Explosion). This would cause the piston rods to be projected like arrows into anything in their line of fire. Reports about incidents similar to this have come across my desk several times over the last 20 years. One firefighter had a piston impaled in his hand as the projectile launched out of the front end during a car fire. Another non-suspecting firefighter caught a piston in his leg. Imagine the terrible consequences that could occur if someone were to receive a stray piston in his or her head.

A similar danger could be posed by the lift cylinders (used with the hood, trunk, rear window glass and hatchback) that exist on many vehicle models already burning up the road. Photo 2 shows an SUV with its rear hatch gate open and the lift-assist cylinders in plain view. There is only one set of pistons visible in that photo, but there is actually a second set onboard and these are used to help lift the window. Now, take a good, close look at this type of window. If the window were closed and the cylinder compressed, ask yourself what would happen if you needed to break the glass to gain entry into this vehicle and you made the obvious choice of breaking the window farthest from the patient. Chances are that those loaded (and hidden) gas cylinders would blast bits of broken glass right into your face, or anyone else's face who happened to be nearby.

Photo 2: You can see the lift-assist cylinders on this SUV, but those aren't the only pistons in that system. To avoid gas-cylinder hazards, some manufacturers are moving to new spring-loaded lifting hinges (inset).

However, what's new for the 2004 model year (and good news for us firefighters) is that some vehicles with lift gates now do not employ any gas cylinder lift-assist devices to support the rear hatch when you open the door. This is the case with Volkswagen's 2004 Tourareg that's shown in the inset photo contained within Photo 2. Several leading manufacturers are now replacing the pressurized gas cylinders with spring-loaded devices.

The XLR Safety Zone

The XLR contains several noteworthy safety features, including frontal air bags with a keyed passenger-side frontal air bag shutoff switch (located inside the glove compartment) and an indicator light positioned on the center console that illuminates when the bag is turned off. This feature is included because the car is only a two-seater, and the passenger seat may be occupied by a baby or a small person. With the feature, the driver can turn off the air bag system on the passenger side to protect that rider from air bag impact, which could pose the threat of injury, given that the restraints are designed for an average, grown person who fits into the 95th percentile of sizes.

The XLR seats contain side-impact head and thorax air bags. Seatbelt pretensioners are provided for the lap portion of the belt, indicating that the pyrotechnic device is located on the latch portion of the belt. (While we are discussing this topic, I should mention another "first" I saw at this year's show. Side-mounted side-impact air bags are normally mounted on the doors. However, this year I saw a two-door Mercedes that has rear seating. Its air bags were mounted in the side rear-quarter sections. In Photo 3, you can also notice that there is no B post on this particular vehicle.)

Photo 3: A new first: This two-door Mercedes SL500 has air bags mounted in its side rear-quarter sections.

Hot Stuff

The XLR is a hot little automobile with a genuinely cool design. The designers at General Motors wanted to make a car that competes with the Mercedes-Benz SL500, the Jaguar XK8 and the Lexus SC430. To help achieve this, the design team gave the car some interesting features. This sports car has keyless access, but its design really means that it is totally keyless. The driver needs only to have a key fob (Photo 4) in his pocket to operate the doors and trunk, and even the ignition. The button with the yellow circle around it is the button the driver pushes to start the car or turn it off. No key is ever needed as long as the key fob is within the working range.

Photo 4: The XLR's start/stop button (circled) operates only if the key fob (inset) is within range.

The driver doesn't need keys to gain entry into the car but needs to be within a four-foot radius to be able to open the car door. Because this car has no door handles to grasp and pull, it could be tricky for rescuers to get into the vehicle if it were involved in a crash. The upper rear edge of the door has an indentation area where one would normally reach in and touch the finger pad, thus causing the door to unlatch and open. This may become a problem if there is no battery power available, so I will show you some solutions to that problem.

Should the power go dead while you're inside the car, you won't be able to get out of the car in the conventional way. The inside door release operates the same way that the outside release works-strictly by touch and only when the switch is powered. If there is no power to release the door lock then you will need to look for a mechanical release. In this case, the mechanical release is located on the floor beside the seat and is similar to the release mechanism for trunks and gas-cap covers. If the windows are up, there is no electrical power, and the persons inside are nonresponsive, then you must look for another avenue of access, such as breaking glass.

In Through The Out Door

Now there is another way into the car that is less damaging than breaking windows. On the left side of the rear bumper there is a small square knockout piece. Pop out the square piece and insert the key (the only key that you receive with this car) into the key switch hidden behind the bumper. This will allow you access into the car's trunk, where you will find another surprise.

This car is pretty unique but not anything out of the ordinary by today's cutting-edge standards. With the XLR you can just push a button to start the car. On another car, however, such as the Mercedes-Benz SLK500 (Photo 6), starting and stopping is just a matter of touching the top of the shifter knob.

Photo 5: Start, stop, and shift: One button does it all on the Mercedes SLK500.

Learning The ROPS

These are some of the things that you should know when dealing with newer vehicles. The best way to learn even more is to attend auto shows or visit car dealers for a training session. You and your crew will be quite surprised at how helpful the service and sales people are when you tell them why you're there. (Unfortunately, don't expect them to let you cut and pry apart any of their vehicles. They have some strict rules about that...)

Since the introduction of frontal air bag systems, injuries to the chest and head have been reduced dramatically. However, other injuries have become more prominent, such as extremity injuries. Hands and arms get thrown into windshields, doorposts and even faces. Legs and knees are suffering some major damage in this regard, and to combat that, manufacturers are installing knee air bags. Kia was the first company to install knee bags several years ago, but now they are showing up in many vehicles. You can see knee bags tucked away in the vehicle shown in Photo 7.

Photo 6: Knee air bags, such as this one on a Kia, provide protection down under.

Over the years, I've written about rollover protection systems (or ROPS, as they are known in the trade). Mercedes is continuing with its pop-up roll bar and the Audi and the BMW have their own styles of pop-up roll bars. A word of caution about these ROPS systems: They are spring-loaded and are set off when a vehicle is hit in the side. Sometimes the car has been impacted only slightly, or the car becomes unstable and, because of this, reaches its setoff point. The sensor governing this action is a pendulum-type and has been known to trigger the ROPS during hard, fast turns or when a car "caught air" after hitting a slight bump in the road. As rescuers, we should be careful when providing possible C-spine support and we're leaning over the ROPS. I haven't heard of any accidental deployments, but the possibility is there.

That wraps up our coverage of the 2003 North American International Auto Show. Next time, it's back to the streets for more lessons in vehicle extrication. Until then, remember that in everything you do, you should B.E. S.A.F.E. - Before Everything, Stop And First Evaluate.