Unveiled last November at the National Association for Pupil Transportation’s trade show in Denver, the new Saf-T-Liner ER by Thomas Built Buses created a steady buzz in the exhibition hall. The modern styling, especially, set it apart from more traditional school bus models. But the aesthetic sophistication of the Saf-T-Liner is only part of the package, according to Thomas engineers. In the following interview, SCHOOL BUS FLEET Editor Steve Hirano discussed the Saf-T-Liner’s enhancements, both aesthetic and functional, with Ed Swaim, product manager for transit-style buses at Thomas, who says the bus’ beauty is more than skin deep.
SBF: According to your marketing material, the front of the new Saf-T-Liner is made from a composite rather than steel. What material was used?
Swaim: It’s called VRIM, which is a trade name. It’s made by a company called Airshield Corp. in Brownsville, Texas. It’s a type of fiberglass that’s very strong and tough. The advantages are that the composite is lighter, and you don’t have to be concerned about corrosion. You can also style it better because it’s easier to shape.
SBF: How did you decide to incorporate VRIM into the front of the bus?
Swaim: It allowed us to put together the design that we were looking for. Using composites is also part of an industry trend in truck and bus design. The other major factor was the fact that it won’t rust, because corrosion is an issue in buses and trucks.
SBF: Beyond the aesthetics, what were your objectives in designing this bus?
Swaim: One of the key things was improving the human factors, such as driver ergonomics. In other words, we were trying to give the driver more space, additional pedal angles, greater visibility and improved appearance of the driver compartment, to make it more user-friendly.
SBF: When you say "more space" for the driver, can you be more specific?
Swaim: There’s more space fore and aft along the seat track, and there’s more space for the driver’s feet.
SBF: What other objectives did you have?
Swaim: We also wanted to satisfy the needs of the service technician, including making the product much easier to work on. For example, we designed an entirely new electrical system that uses printed circuit-board technology. Rather than using the typical "bus boards" which use ring terminals and butt splices, every wire with these terminal boards has a connector that just plugs into the PC board. The mechanics are also going to like it because every circuit has LED diagnostics that help to identify a problem should one occur. These LED lights are just a super trouble-shooting mechanism.
SBF: Beyond the circuit-board technology and LED indicators in the electrical system, are there any improvements in the service-friendliness of this bus?
Swaim: Yes, we went much, much deeper than that. We have an access panel on the front of the bus that is basically the whole front fascia below the windshield. When it’s hinged open, it exposes the industry’s first firewall on a school bus. This is a rear-engine bus, so we’re not separating the engine, obviously, but we’re separating the interior of the bus from the outside. What this does is gives the technician access to components that they would typically have to look really hard to find. When he lowers this panel, they’re just staring at him. It gives him access to the steering shaft, brake valves and switches, the windshield wiper system, air brake pneumatics and electrical connections. The other big item that’s located on the firewall is the heater system, which is mounted on slide-out trays. You can change the heater core in minutes where it used to take hours.
SBF: Did you use focus groups to determine what your customers wanted?
Swaim: Last July, we brought in three different groups of school bus drivers in North Carolina and interviewed them one at a time. First, we did an oral interview and then we had them fill out a questionnaire. We also put them in the driver’s seat and then measured them, so we could be sure that they fit in the cockpit of the bus like we expected them to. We checked the steering column angle as well as the angle and heights of the brake and accelerator pedals. We inquired about seating comfort and adjustability and made sure that the controls were easy to reach. We also looked at the layout of the instrument panel to make sure the gauges and displays were easy to read.
SBF: Did you interview any other groups besides drivers?
Swaim: In the fall, we invited about 30 of our biggest and best customers throughout the United States. We had some state officials, national contractors and individual school districts. They were given a "sneak preview." One by one, these people sat in the bus. Then we interviewed them. After both of these focus groups, we sat down with our engineers and made changes.
SBF: So some of the feedback that you received from the participants was incorporated in the final design?
Swaim: Oh, yes, we changed some of the locations of the switches and several other things. We are great manufacturers and designers, but we’re not operators. That’s why we brought these people in. We learned quite a bit from them.
SBF: Did you have any other objectives in mind when you designed this bus?
Swaim: The other thing that we wanted to accomplish was to build a bus that had a much-improved and more professional appearance, both inside and out. We were trying to update the styling. And we succeeded. The other objective that we had was to improve the manufacturing process. This is a highly tooled bus. Every part is tooled, which improves the quality and consistency of the parts and streamlines the manufacturing process. You pay a big price for this type of tooling, but you’ll see better consistency because of it.
SBF: Was there any collaboration with Freightliner on the design of this bus?
Swaim: Part of our objective was for this bus to have a Freightliner look to it. If you look at this bus and compare it to some of Freightliner’s trucks, you’ll see a lot of similarities. Some of the same parts, such as the headlights and instrument cluster, come straight out of the Freightliner assembly line. It was also partly to take advantage of economies of scale offered by Freightliner’s corporate manufacturing structure.
SBF: From a product enhancement standpoint, what other advances does this model have?
Swaim: One of its unique features is the European-style, integrated mirror system. It houses all three required mirror heads into one cluster. It eliminates all of the "jungle gym" of brackets and arms that you see on today’s buses. And the visibility is awesome. It also has an integrated crossing gate, which is recessed into the bumper. That keeps the crossing gate from flopping around in the wind. It also protects the crossing gate from damage if the bumper should, say, bump into another bus in a loading zone.
SBF: Were there any changes to the chassis?
Swaim: We have a very innovative cooling system on this bus. We’re using a side-by-side radiator and charged-air cooling system. Your typical radiator and charger cooler is stacked, one on top of the other. We have set them side by side, which improves cooling efficiency. One thing the service people are going to like is the fact that they’re self-cleaning. Because they sit side by side, there’s no way for dirt or leaves or salt to get trapped between them. We also have a bolted tank design with stainless steel tanks. That’s a major advantage in terms of durability and longevity.
SBF: When is this new model going to be made available?
Swaim: We plan to begin full production in September.