A series of dams helped maintain operations during the construction of the new low-lift pumphouse.
During an early phase of construction on the new low-lift pumphouse at Ras Tanura, pre-cast concrete dam modules were lowered into place across the seawater intake canal beside the pumphouse foundation pilings. Seven pumps were later installed in the finished building (seen in the photo), six of them transferred from the old facility without interruption of the vital pumping process.
From the March 15, 1978 edition of The Arabian Sun.
A new low-lift pumphouse that supplies the Ras Tanura Refinery with 5.7 million barrels of seawater per day was put into service March 4, replacing its predecessor in a construction operation that allowed for no interruption of the vital water flow at any time during the project.
Seawater is used primarily for cooling in both the refinery process and in the power plant areas; it is also used a feedstock to desalination plants that produce potable drinking water, and as boiler feedwater.
The new structure was built on a marine-type platform installed across the intake canal, 50 feet to the seaward side of the old pumphouse. Between the two structures, a dam -- made of 13 pre-cast concrete sections -- was constructed to span the canal's 100-foot width.
Tunnel-like opening in each module allowed the water to flow at an undiminished rate while the pumps were transferred and installed, one at a time, into the new building "upstream."
Temporary pipelines routed their discharge into the canal at the landward sie of the old facility.
Once all the pumps were installed and operating, the gates of the dam were closed, a second, temporary dam, was constructed on the landward side of the old building, and the water thus contained was pumped out to both expedite removal of the old pumphouse and to permit construction of a concrete basin in the gap left by the demolition.
— The Arabian Sun: March 15, 2023