The Inga-Shaba Extra High Voltage D.C. Intertie, as it was officially called, represented one of the United States' most important third world commitments of the 1970s and 1980s. However, construction progress was plagued by rebel insurgency in Southern Zaire, massive logistical challenges, cost overruns, and financing delays.
By utilizing the hydroelectric potential of the Inga Dam and by constructing one switching station near Kinshasa at Selo, the Government of Zaire under the autocratic Mobutu Sese Seko was theoretically able to control the flow of power to secession-prone Katanga, then Shaba, province, but never exercised this option. Belgians from Tractionel, argued that more economical alternatives were available nearer Shaba, using low-head generator plants, but were overlooked in favor of the American consortium, consisting of Morrison-Knudsen International (Prime Contractor), plus Swedish (ASEA), Italian (Sadelmi-Cogepi) and Irish (GE Subsidiary) sub-contractors. The project was initially conceived as a US$ 250 million contract - but cost overruns, partly due to unanticipated armed conflict in Shaba Province, pushed the final price up over US$ 1 billion, with unofficial estimates ranging as high as US$ 1.3 billion, inclusive of a comprehensive Operations and Maintenance Contract.
It has been postulated in some circles that the Inga-Shaba Project provided a significant source of rent-extraction for Mobutu and the Ministry of Energy, with tentative evidence suggesting that Mobutu may have insisted on approximately 4% in personal commissions. The Inga-Shaba Project accounted for approximately 20% of the former Zaire's debt burden, the total amount of which was 5 Billion USD at the time.
The project was dedicated in 1982 at Kolwezi by Neal Spencer, MKI Executive Vice President, Munga Mibindo, President Delegate General of the National Electrical Utility, and Arthur Madsen, the Project's Chief Translator.
The ten-year project entailed design and construction of a 1700 kilometer electrical transmission line from the mouth of the Congo River, specifically from the Inga Dam, one of Africa's three largest hydroelectric complexes, to the distant copper mining region then known as Shaba, today Katanga. It featured switching stations at Selo (near Kinshasa), Kikwit, Kananga and Kamina, prior to delivering power to the Kolwezi Inverter Station.
"Inga-Shaba" was the nickname given to this project, which, operating initially at only 10% of capacity, first delivered power in 1982.
This scheme, equipped with modern thyristor technology provided by Swedish subcontractor ASEA, was designed to transmit 560 megawatts, in the first phase, at a symmetrical bipolar voltage of +/-500 kilovolts. It is the longest EHVDC transmission line to date, except for one in Siberia. Because the line runs through relatively inaccessible terrain, an unusually broad right-of-way was cleared, at considerable expense, to ensure tower integrity.