Turtle Top shows what it’s made of
An inside look at construction and component testing
By David Hubbard
Turtle Top stakes its claim on its buses standing the test of time by sticking to its roots and building products as solid as the company’s foundation. From the standpoint of design, construction and product testing, Turtle Top buses are renowned for their full, primed roll cage and exceptionally strong load-bearing floor.
Throughout the process the vehicles and components undergo rigorous and extensive testing to ensure FMVSS compliance and years of continual use.
Inside the Turtle Top construction process
Construction of a Turtle Top vehicle begins at the floor starting with G-channel cross members that stretch from wall to wall (photo 1) followed by a full perimeter frame (photo 2). Most of the weight from the construction of the cage ends up on the exterior perimeter frame where the walls meet and seats are installed.
Center aisle stiffeners built of reverse cap steel C-channel (photo 3) prevents the aisle from sagging after years of operation. The seat tracks also mounted on reverse cap steel C-channels have been tested and certified to exceed DOT Standards.
The contoured walls add strength, aerodynamic wind advantages and aesthetics that complement the quality and style. Steel corner window gussets (photo 4) add perimeter sidewall strength and create a solid built frame for the windows that prevents window sags and water leaks. All welds are made with a continuous bead as opposed to spot welding.
One test at a time
Turtle Top says its proprietary testing and compliance program ensures product safety and durability. Rather than rely solely on vendor test results, the company works with an independent agency. One test simulates vehicle usage and confirms its vehicles are among the safest in the industry.
The goal is to meet and exceed Federal Motor Vehicle Safety Standards (FMVSS). In addition to the required testing in its own research and development facility, independent labs for FMVSS safety testing include the Federal Testing Center and MGA Research Component Body Strength Testing Federal Bus Testing.
Here are a few examples of the tests Turtle Top conducts during the design and construction stages and on the finished product prior to shipping.
FMVSS 207 requires seating systems to meet standard of safety regulations involving strength of the assembly and installation. Turtle Top tests all seating assemblies in the vehicle to ensure normal operating data as compared to a crash. Forces required in these tests vary from 3,000 to 12,000 pounds
Turtle Top installs three-point safety belt systems that meet FMVSS 208 Occupant Crash Protection standards for occupant protection devices and assemblies. Turtle Top is active with vendors/chassis manufacturers in the required testing for installation with respect to FMVSS 209-210 Seat Belt Assemblies.
FMVSS 105 requires vehicle brake systems to adequately support the weight and center of gravity of the vehicle. Turtle Top conducts tests for this at Bosch Proving Grounds and Progressive Engineering.
Additional weight and CG calculations are done on each vehicle before shipment.
Other FMVSS testing addresses the flammability of interior materials (FMVSS 305); lamps and reflective devices (FMVSS 108); and emergency exit and window retention (FMVSS 217).
Cycle tests conducted to improve design and installation prove the durability of a product through rigorous repetitive motion. Advantech cycle tests also serve to hold vendors accountable prior to the release of a product.
HVAC testing in independent test labs and generally in accordance with SAE specifications verifies passenger comfort from an affective heating and cooling system.
Turtle Top conducts continuous water testing during design and prior to shipping in a booth designed for testing at a steady 200 gallons per minute.
For every bus that rolls off the line Turtle Top offers Greenshield Protection, a robust comprehensive warranty plan that the company says stands as its pledge to safety and customer satisfaction.
Before construction begins the frame is painted in primer black.