However, between some of the stations an additional safety device is necessary. Automatically controlled valves at three of the intermediate units are designed to allow release of crude oil from the main line into special relief tanks at times of critical surge.

At Turaif, which operates two permanently mounted combustion turbine units and three electric motor- driven centrifugal pumps, instead of the six diesel-driven pumps used at the other main stations, Tapline operates a unique hydraulic booster pump driven by high pressure crude oil from the line itself. Here is how it works:

After the oil leaves the main combustionturbine-driven pumping units at high pressure, a small part of it is diverted into the hydraulic turbine. This turbine is similar to a centrifugal pump, except that high-pressure oil is forced through it, causing it to rotate. The rotation of the hydraulic turbine then drives a conventional centrifugal booster pump, which boosts the suction pressure of the main oil stream to that required for satisfactory operation of the high-speed combustion-turbine-driven pumps.

NEW PEAK LOADING RATES ATTAINED

At its modern terminal south of Sidon, Tapline can load the largest tankers now afloat at rates exceeding 60,000 barrels an hour, higher than those of any similar terminal in the world. From its tank farm 350 feet above the water, comprising twenty 180,000-barrel storage tanks with a total capacity of nearly four million barrels, oil flows by gravity to tankers moored offshore. The four deep-water berths, located up to two kilometers offshore, can accommodate many ships too deep in draft to transit the Suez Canal fully loaded.

At one Sidon berth, a new 36-inch submarine pipeline was installed in 1963 during a two-day launching operation demanding considerable ingenuity. The 6,650 feet of pipe was welded onshore, then floated offshore into proper position in a single piece. To control bending stresses during its submergence to the sea bed, the pipe was filled progressively with lightweight naphtha, followed by sea water, and was thus successfully lowered into place. This was the first time that a submarine pipeline has been laid in this manner.

The terminal also was the first to use loading hose as large as sixteen inches in diameter, and the first to provide radio contact with tank ships from their arrival until their departure.

MODERN TOOL: THE COMPUTER

To evaluate its operating policies and possible future modifications of its system, Tapline uses another modern management tool: the high-speed electronic computer. In cooperation with Esso Research and Engineering Company, a program has been devised whereby all factors entering into the operation of the pipeline can be put into mathematical equations, varied and analyzed by the computer.

In each computation, an entire year's pipeline operations can be simulated within a few minutes, making it possible to determine accurately and at small cost the effect of future facilities improvements or changes in operating policy.

The system has been successfully used to determine the most efficient pipeline operating levels , and whether pipeline pumping power should be increased or tanker loading and storage facilities at the Sidon terminal should be expanded.

Capable of simulating a year's operations within minutes, electronic computer is valuable planning tool.