Wayne Lifeguard

In the late 1960s, a weak point and location of structural failure in catastrophic school bus crashes was considered to be body joints, the points where panels and pieces were fastened together. Longitudinal steel guard rails had been in use since the 1930s to protect the sides of buses, but behind them on the sides and on the roofs, manufacturers used many individual panels to construct a bus body.

Around 1967, safety engineers at Ward Body Works of Conway, Arkansas subjected one of their school bus bodies to a multiple roll test, and noted the separation at the joints.[2] Ward engineers noted that many of their competitors were using far fewer rivets. This resulted in new attention by all body manufacturers to the number and quality of fasteners. To Wayne engineers, simply increasing the number of fasteners (rivets, screws, and huckbolts) was not satisfactory. In their own tests, the joints were always the weak point under high stress loads regardless of the number of fasteners. They also noted how the continuous guard rails used on the sides tended to spread the stress away from the point of impact, allowing it to be shared and dissipated at portions of the body structure further away. Instead of trying to figure out how to make the fasteners do a better job, the engineers stood back and wondered how the design features of the guard rails could be expanded. The result was a revolutionary new design in school bus construction: continuous longitudinal interior and exterior panels for the sides and roofs.

Branded the Lifeguard, Wayne's new conventional-style school bus design used the company's roll-forming presses to make single steel stampings that extended the entire length of the bus body.[3][4] The concept was that by reducing the number of joints, the number of places where the body could be anticipated to separate in a catastrophic impact was reduced in a like amount. The "Lifeguard" design reduced overall body weight, the number of fasteners used, and man-hours required for assembly. However, the roll-form presses were very large, requiring special equipment to handle the finished panels. A more practical problem was the panels had to be cut to exact length for each bus body order, which varied with seating capacities and from state-to-state specifications. This created a marketing disadvantage as the Wayne factory required greater manufacturing lead time than in the past whereas the previous technology allowed for more interchangeability and customization in orders.

Shortly after the Lifeguard was introduced, Wayne held a nationwide contest soliciting ideas to improve school bus safety, with a new Lifeguard school bus as the grand prize. The winning entry was submitted by a school bus driver in Goochland County, Virginia, whose district received the new school bus. Her idea was to incorporate sound baffles in the ceiling of school bus bodies to help reduce driver distraction. Compact forms of such equipment were later developed used by Wayne and other school bus manufacturers when diesel engines (and their greater noise) became more widely available in conventional-style school buses (like the Lifeguard) in the 1980s.

The benefits of the Lifeguard design were proved in several potentially catastrophic collisions. For example, in 1982, at Petersburg, Virginia, a 1973 Wayne Lifeguard school bus transporting 41 elementary school children was struck broad-side at an intersection by a fire truck that had gone through a red traffic signal without stopping while responding to an alarm.

The school bus was rocked violently, but after the fire truck literally bounced off of it (rather than penetrating the body); the bus driver was able to regain control and stop safely. The fire truck was spun 180° and its front was demolished; all 3 firefighters were hospitalized. The bus driver and all children were transported to the hospital as well. One child on the bus suffered a broken arm; the rest were mostly scared but uninjured.

Further investigation of the collision revealed that the impact of the fire truck had failed to overcome the strength of the longitudinal panels and the guard rails. Investigators discovered that despite a bulge of several inches on the longitudinal interior panel, there had been no all-the way through penetration of the passenger compartment whatsoever, no joint separation, and no sharp edges created. Instead, they found the substantial impact stress had been shared over a widespread area along the entire structure of the passenger compartment "box", protecting the occupants as intended by the design.