headache bar
n.— «You can walk right up to the huge, H-shaped “headache bars” that lift the 48-inch-diameter pipeline eight feet off the ground; the bars allow it to slide and shift with changes in temperature.» —“Alaska: Not Too Big for a Weekend” by Julie Gangler in Anchorage, Alaska Los Angeles Times June 19, 1983. (source: Double-Tongued Dictionary)