University of Extrication: The “Gun Barrel” Boron Pipe—Part 1

Subject: Ultra-High-Strength Steel

Topic: The “Gun Barrel” Boron Pipe

Objective: Understanding the challenges of ultra-high-strength steel in vehicle structures

Task: Given a 2003-2011 Volkswagen New Beetle convertible, the rescue team shall use rescue-cutting tools to sever the “Gun Barrel” Boron steel pipe found inside the A-pillars.

This University of Extrication column examines a unique design of ultra-high-strength Boron steel found in selected Volkswagen and Audi vehicles that are on the road today. This specific Boron steel design consists of a large hollow steel pipe having a diameter of 1 3/8 inches. The thick walls of this Boron pipe are 3/8 inches thick. Responders typically refer to this as the “Gun Barrel” Boron pipe design.

In the New Beetle convertible, a gun barrel pipe inside each A-pillar creates two strong A-pillars. In a rollover crash, these A-pillars become the front rollbars to protect the occupants. The VW convertible also has two deployable rollbars—one behind each rear seat. These deploy as the car tilts to serve as the rear support during the rollover collision.

Admittedly, it would be a rare situation where a rescue team has to cut the A-pillars of this convertible. Doors, sidewall and especially the ragtop roof make for easy access to trapped patients. The point here, however, is that the steel used by Volkswagen in this convertible since as far back as their 2003 model year is very tough. It may, in fact, be found to be beyond the cutting capability of the power rescue tools you currently have on your rescue vehicle.

In Part 2 of our look at this unique Gun Barrel Boron pipe design, we’ll reveal how we cut through this pillar and the lessons learned during this research.