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OOSC, Part II, Item 3. Coupling Devices, b. Upper Coupler - Flathead Countersunk Socket Head Caps

Entry DateMay 1, 2024
Issue Number24-028-VEH
NameDale Vecera
AgencyHouston Police Department
Address1200 TravisHouston, Texas, 77002United StatesMap It (opens in a new tab)
Phone713-898-0471
Email[email protected]
CommitteeVehicle Committee
StatusClosed
Summary of Issue

The issue encountered involves loose mounting fasteners on a bolted upper coupler assembly and more specifically what action to take when encountering flat countersunk socket head cap screws as mentioned in the Note under Coupling Devices, Sec. 3. b. (4). On a recent inspection of a flatbed trailer, the upper coupler assembly (which includes the kingpin) was bolted to the main I-beams for the frame of the trailer utilizing countersunk socket head cap screws. 5 countersunk screws were used on each side left and right with 2 loose on the left side and 1 on the right side. I have included a picture to show that separation was beginning to occur between the bolted kingpin mounting plate and frame rails of the trailer.

Justification or Need

More guidance is needed for inspectors on what enforcement action to take, if any, before one of these upper coupler assemblies (which are using countersunk socket head cap screws) comes unattached causing a trailer to come loose from the towing unit.

Request for Action

Request for a decision to be made on how inspectors should handle countersunk fasteners being used on coupler assemblies.