When a terminal is installed on a steep grade, what is the proper placement of the impact head?
• The important thing to remember is to keep the impact head parallel to the guardrail, not perpendicular to post #1. The reason is to allow the head to freely travel down the rail. The SKT and FLEAT impact heads are connected to the first post of the terminal with either two lag screws (for a wood post) or two hex head bolts (for a steel post). When the system is impacted end-on, the impact head only needs to move a short distance before the first post is fractured. The connection of the impact head to the post needs to be strong enough to support the weight of the head prior to impact. If the terminal is placed on a hill and the posts are driven so they will not be perpendicular to the guardrail, the post bracket angle on the impact head will not set flush against the post. Normally that gap will not exceed a width that will prevent the lag screw or hex bolt from holding the impact head to the post. If under extreme circumstances the gap becomes too large and the connection is not se
