Although the environmental, technical and economic feasibility of an arctic pipeline are considered to have been demonstrated, it is realized that some further work and research remains to be done, and detailed designs and plans would have to be prepared. The principal areas of research (as differentiated from more routine engineering effort) in which further investigation is needed are suggested below.

1. When a specific route has been established for an oil pipeline, it may be necessary to gather further basic data in the field in order to assess and prepare a comprehensive statement on environmental impact.

2. Sociological developments in the areas affected by the pipeline should continue to be studied. 3. Further research is needed to improve the method of predicting ice content in soil, and the development of a terrain classification system. This work is now in progress.

4. More comprehensive slope-stability data are needed. This work too is in process.

5. The mathematical model used to predict thermal regimes will be modified to include additional research data as its becomes available.

6. Present seismic information is somewhat incomplete. More would be desirable, and a program to that end is contemplated.

The design criteria for this study are based on sound engineering principles applied to a particularly demanding environment, and meet the requirements of all applicable government regulations. Because of the extreme conditions, this line is designed to be of higher quality and reliability in almost every respect than the minimums recommended in existing codes and standards. Hydraulic and thermal gradients for the pipeline at 1.8 MMBD throughput are shown in Exhibit 11.

Large differential temperatures (up to 170° F) between the warm oil and the cold environment would impose additional stresses on the pipe when installed. These stresses were calculated and considered in the design. The necessary thickness of the pipe wall (up to 0.6") for the operating pressures anticipated, and the insulation necessary for the temperature conditions had to be decided after detailed analysis. The difficulties that might be caused by increased oil viscosity due to cooling after shutdown, were thoroughly analyzed by the use of a computer program designed for this purpose, and provided for in the insulation design. For aboveground installation, a continuous zig-zag pile-supported configuration was decided on, with ground anchors at points requiring full restraint (Exhibit 12).

The initial design capacity of the pipeline would be 800,000 barrels per day, with 10 pump stations each having an average brake horsepower of 11,080. A typical layout of a far northern station is illustrated in Exhibit 9. The station constructed schedule is based on a throughput increase over 6 years to 1.8 million barrels per day, requiring 22-pump stations with an average of 35,000 horsepower each. The line could be expanded to a capacity of 2.5 million barrels per day with 46 pump stations of 42,000 horsepower each, or by laying additional sections of pipe in parallel. Overall pump efficiency was estimated at 85 percent.

The pumps selected for the study were doublesuction horizontal split-case pumps, arranged in

series or parallel, and driven by aircraft-type pa generator-power turbine combinations. Some sub has been made of the alternative of using cleatsdriven pumps supplied from hydro-electric develo ment. Maximum operating pressure for the 65 wall, 48"-diameter pipe of 65,000 psi MSYS, is 93 pounds per square inch.

Pump stations and terminals were designed for maximum reliability and self-sufficiency. Electrice for the stations would be supplied by generation on the site. Each station would have standby genentors and pumps, plus emergency equipment. Conputerized monitoring and control of oil-flow would be programmed with provision for safe and spect shutdown and isolation in emergency. Quarte would be provided for permanent maintenance staf The station buildings and equipment would b elevated on gravel pads to insulate the permafros A complete fire protective system would be an im portant part of each station and terminal.

To allow continuous operation, tanks of ad quate capacity must be provided at Prudhoe Bay These tanks would be elevated on gravel foundation above the permafrost. Storage tanks at Edmonton would be the responsibility of the oil receiver. Al terminal and station areas would have a controlled drainage system to trap and recover any oil.

A high quality and dependable communications system is vital to this line. A temporary system would be installed during the construction phase. to be superseded by a highly sophisticated, automated supervisory-control system when operation began. Emergency fail-safe provisions would be corporated into the system. The computerized com munication system would monitor and control ail flow, pressure and other operating conditions, and gather and store information on the condition of machinery, inventory of parts and other useful data. The same buildings, towers, and other facilities would be used for both systems to minimize both cost and environmental disruption.