8555-02 GM Detroit Factory Zero

STATEMENT OF PROBLEM

Chassis Mod 1 all of the Mod sections were constructed of 8" channel. The Channels were "Toe Clipped" to an inverted "T" iron, as known the channel has a slanted surface. the supplier did not have the correct type of set-up for the Toe Clip Connection. The supplier was responsible for the "Toe Clip" connections. 
This was carried through Mod 1, 2, and 6
 

ROOT CAUSE

Assumptions were made the Sections would have the proper bolts for the Mod sections

COURSE OF ACTION

General Motors told the supplier that they had to make corrections to the bolting methods for Mod 3, 4, & 5.

A direct bolt connection was chosen by the supplier for the Mod sections to the hanger steel. 
This included a through bolt with a hillside washer for the direct bolt connection.

LESSON FOR FUTURE PROJECTS

The direct bolt method caused hangers to hang out of "Plumb" and bracing to be either too short or too long. 

Try to convince the customer that a header installed end to end on the same plane on the bottom chord of the truss would solve all of these issues.