pole’s breakaway mechanism was a three-bolt triangular slip base. The triangular slip base was oriented such that one side of the triangle was perpendicular to the FOIL runway. This side was the impact side of the pole. The pole foundation plate was bolted to the FOIL runway base plate using three 25-mm bolts. A 28-gage sheet keeper plate was installed between the pole slip plate and the pole foundation plate. The pole had a 6-m-long mast arm with a simulated light (in mass only) attached such that it projected to the right-hand side, or front end of the impacting pickup truck. The pole’s individual components were weighed and the total weight was determined. The c.g. of the mast arm and pole, and system c.g. also were determined. The bolt torque recommended by an engineering drawing supplied with the light pole was 280 N·m per bolt. The torque value chosen is the current Arizona specification and has been used during frontal recertification tests and in computer simulations of collisions between a Chevy pickup truck and a slip base luminaire support. This torque value is higher than the FHWA-recommended bolt torque for slip base luminaire supports. The bolts used were 32-mm grade 8 (high-strength) strain gage bolts. The bolt torque was converted to bolt tension so that the strain gage bolt output could be used to set the bolt tension. The torque-to-tension relationship used is outlined in the report Dynamic Testing of Luminaire Supports.⁽²⁾ The clamping load calculated for a dry- lubricated 32-mm bolt torqued to 280 N·m was 44,500 N per bolt. The morning of the test, the bolts were lubricated with a dry lubricant and the bolt tension was set by monitoring output from the bolts until the desired voltage output was achieved. The output from the strain gage bolts during the test was recorded via an umbilical cable between the pole and a Honeywell 5600E FM tape recorder. The tape was played back through an analog-to-digital converter (ADC) with a sampling rate of 5000 Hz. Table 4 summarizes the physical properties of the lighting standard. Figure 5 is a drawing of the lighting standard and slip base.

 

Table 4. Lighting standard physical properties .
Manufacturer	Valmont Industries
Part no.	DS32-E00E450-20S-GV-HH-SLP
Pole height	13.7 m
Overall mounting height	15.3 m
Pole material	Steel
Pole weight	332 kg
Mast arm weight	85 kg
Simulated light fixture weight	25 kg
Total system weight	442 kg