Technology Countdown: Roll-cage evolution

February 28, 2013, Farrah Kaye, NASCAR.com

Roll-cage evolution

The roll cage has come a long way since it first debuted in NASCAR in the 1960s

In 1949, one year after NASCAR became incorporated, stock cars raced in Charlotte with limited safety additions. Short of a seatbelt (or a rope, which held the driver in place better) and goggles, there wasn’t much difference between the cars in the parking lot and the cars on the track.

In 1952, roll bars were in use, but were not required and most teams chose not to install them. Roll cages, which included more parts and offered more safety, however, started to become more common in the cars. Tim Flock made headlines after winning the 1952 Modified-Sportsman race at Daytona Beach but was disqualified when it was discovered his roll cage was made of wood.

Teams became inventive, using bed frames and other devices to create the roll bars.

Then came the 1960s and roll-cage structures. They became a more important part of the car itself and were used to stiffen the chassis. This improved the handling and more obviously, the safety of the cars.

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Roll-cage evolution

It was put together using a variety of triangulated bars from front to back, across the midsection of the car.  Bars were also in the doors to stiffen and strengthen the cars to protect the driver.

But times have changed. Since then, NASCAR race cars must have a roll cage and must meet certain dimension and color requirements. The roll cage is one of three parts of the frame of the car, which also includes the front and rear clips. The roll cage is part of the middle section.

While the front and rear clips are built from thin steel tubing and will crush upon impact, the middle section will stay intact. The front clip’s design is to push the engine out of the bottom of the car instead of into the cockpit, where the driver sits.

Ryan Newman -- who holds a degree in Mechanical Engineering from Purdue University -- made headlines in 2009 when he flipped several times, at Talladega, eventually landing on his roof. It took workers nearly 15 minutes to cut him out after turning his car right-side up. Because of the amount of damage, there was no radio contact until the car was back on four wheels. The roof and roll cage were crushed.

Newman understood the process but felt there was room for improvements.

Fast forward to 2013. The roll cage will be even safer in the Sprint Cup and Nationwide series. Both will have an additional forward roof bar and a center roof support bar that will intersect near the front center of the roll cage. Just as Dale Earnhardt played a key role in improving safety for drivers who came after him, Newman is the same, as the Forward Roof Bar has been called the Newman Bar around the garage.

As for the seat, it is secured to the car’s roll cage with a tubular frame with a minimum of two magnetic-steel, hex head bolts per side with specific dimensions.

The cage assembly must consist of the main frame rails, upper left side frame rail, truck trailing arm crossmember assembly, rear sub-frame assembly and numbered roll bars.

But first, the roll cages must be presented in blueprint form 60 days before the design can be entered into competition. Once approved, the frame itself must be submitted for approval again 30 days before an event.

Each cage has a unique ID code on the ride side of the horizontal shoulder bar. The code must include, in order: the builder, date of manufacture and a sequence number. It's a long way from ropes and seatbelts.

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