Firebase "Rock Crusher"
Jan.  -  Feb. 1968
Operation "Cumberland Trail"
The "Rock Crusher"  Jan  -  Feb  1968

The "Rock Crusher" [RC] was a quarry operated by US Navy Sea
Bees, which produced gravel for construction projects. It was
located at the base of , and over shadowed by Hill 433, a steep and
boulder strewn mountain at coordinates YD713136 [1:50,000 map
of Hue] near Nam Hoa.  Provincial Route QL 547 ran past the RC
and was the East-West corridor that ran between Laos and Hue-Phu
Bai. A pontoon bridge was an extension of QL 547 as it crossed the
Song Huong [Perfume River] and then turned to the North.
Marine Infantry Companies were rotated in and out of the RC to provide security for the Sea Bees. In January of
1968, B Battery 1st Bn., 11th Marines was moved to the RC to provide artillery support for Operation
"Cumberland Trail," which would now convert the RC into a fire support base. 1st Bn. 1st Marine Regiment
would provide security for B Co., 9th Engineers, who were tasked with opening QL 547 for vehicle traffic to the
A Shau Valley and beyond. Charlie Co, 1/1 was providing security at the RC and at the pontoon bridge.

Task Force X-Ray ( 1st Mar Div forward ) in Phu Bai would command and be the operational headquarters for
Operation "Cumberland Trail". With the advent of the TET Offensive on January 31, 1968, Operation
"Cumberland Trail" was scraped and the RC became a static defensive position, denying the use of QL 547 as an
infiltration and resupply route for the North Vietnamese Army [NVA].

Task Force X-Ray now focused its attention on the Battle for Hue and would use the 1st Marine Regiment as the
primary force slated to clear the City of Hue of NVA Regimental forces now occupying Hue. B Battery 1/11
would now support the Marines embattled in Hue with artillery support from the RC. B Co., 9th Engineers would
now assume the role of an additional infantry company providing security for the RC and abandon their engineer
assignments.