THE CHUNNEL: The Amazing Story of the Undersea Crossing of the English Channel.<i> By Drew Fetherston</i> .<i> Times Books: 384 pp., $35</i>

Large engineering projects are invariably multidimensional, and their planning and execution can stretch more than decades, even centuries. Not infrequently, the greatest challenges to overcome before the engineering begins are the political, ecological and economic obstacles.

The Panama Canal, among the great projects heralding the enormous technological achievements of the 20th century, is one example. When Columbus claimed America for Spain in the late 15th century, he was, of course, looking for a westward route to the East. For centuries, explorers searched for a natural waterway along the coast of North, Central and South America that connected the Atlantic and Pacific oceans. Finding no natural solution, a canal across the Isthmus of Panama, in places no wider than 50 miles, was proposed, and a survey was ordered by Charles I of Spain in 1534. Among the objections raised to a canal was a concern that nations other than Spain would benefit from such an easy trade route and that connecting two oceans naturally separated by land might lead to uncontrollable inundation.

Alternatives to a Panamanian crossing were advanced and, by the early 19th century, many alternatives had been proposed, including a canal across Nicaragua and a massive railway that would carry ships high and dry across Mexico. It was the Frenchman Ferdinand De Lesseps who successfully led the effort that resulted in the Suez Canal and who finally took charge in 1879 and initiated the project to dig a canal across the Isthmus of Panama, then a province of Colombia. The French made only modest progress, however, because De Lesseps relied too heavily on the Suez model, a sea-level canal, and made engineering decisions that were not appropriate for the enormous elevation changes encountered in Central America. Frustrated by tropical diseases that decimated the work force and by financial problems, the French consortium abandoned the project after about a decade.

Ten years later, the United States, after encouraging the revolution that created the Republic of Panama, bought the rusting French equipment at bargain prices and, with it, the enormous engineering challenge that had defeated De Lesseps. After removing the political, health and financial problems that blocked the canal, American designers faced some difficult engineering decisions, such as building the famous locks that could elevate ships 80 feet. The completion of the project took still another decade, and the canal opened in 1914, almost four centuries after it was proposed.

The story of great projects like the Panama Canal provides the stuff of epic tales, and few authors have matched David McCullough’s achievements in telling them. His books about the canal and about the building of the Brooklyn Bridge are models of the genre. Drew Fetherston, a newspaper columnist and reporter, chose a late 20th century project analogous to the Panama Canal: the Chunnel. The bare bones of the story lead one to think that it has the same potential as McCullough’s subjects because of the richness of its history. The idea of an English Channel tunnel emerged as many as 250 years before it became a reality in 1993.

The story of the Channel tunnel has the requisite political and economic obstacles of a large engineering project, and there’s even a public health issue: the British national fear of rabid animals finding their way to rabies-free England through a fixed link with France. However, whether it is the dark subterranean and subaqueous nature of the Channel tunnel project or the lack of a larger-than-life hero like De Lesseps or the Brooklyn Bridge’s John Roebling, the “amazing story” promised in Fetherston’s pedestrian subtitle is not fully realized.

There is a bewildering cast of characters in the Channel tunnel story, and Fetherston interviewed 58 men and women who played important roles in the project. Some come alive in the book, but their presence is fleeting. One of the few women in the story, geotechnical engineer Helen Nattrass, appears only for a few pages. Her responsibility was to probe ahead of the tunnel-boring machines so that the geology could be known with some confidence before the massive machines reached a given spot. Such probing was necessary to be sure that the tunnel was progressing within the so-called lower chalk marl, the earthy clay geological formation beneath the English Channel, in some places only 20 meters thick, that made the tunnel an economically and technically feasible undertaking. Unfortunately, Nattrass and her probing disappear after a few pages.

Fetherston acknowledges that, like the tunnel’s engineers, he had to make “hard choices about size” for his book and that writers, like engineers, have to “deal in the art of the possible.” He tells with clarity and conviction how the diameter of the tubes was determined. The smaller a tube, the less expensive it would be to build, but the economics of carrying cars and trucks through the tunnel on oversized railroad cars argued for a larger bore. Other technical factors determining the size of the tubes and the clearance for trains have to do with the piston effect, which refers to how trains compress air ahead of them and thus require more power to maintain their speed. Indeed, the speed of the trains is effectively limited by this phenomenon, and tough decisions had to be made about how to deal with it.

The piston effect also required the construction of numerous cross tunnels, or piston-relief ducts, connecting the two main tubes so that compressed air from one tube could escape into the other. The cross tunnels had to be dug by hand, and determining their diameter was another hard decision that affected the economics of the enterprise. In the end, there was a compromise between a large tunnel facilitating a profitable economic operation and a smaller one that would be more affordable to dig. Fetherston is at his best describing the trade-offs and how the engineering challenges were met.

Perhaps because of his background as a reporter for the Wall Street Journal, Fetherston writes at length about the financing of the tunnel. It might be said that the financial and political obstacles were in fact more difficult to overcome than the technical, for an English Channel tunnel was actually begun by the English in the 19th century and could have been completed with the technology of the time. The British desire to remain a true island also had a lot to do with why that effort was abandoned. With the advent of the airplane, cultural opposition became somewhat defused, and the idea for a Channel tunnel was reopened in the 1950s by the international lawyer Frank Davidson, who has since remained involved with such macro-engineering (technically large-scale and extremely expensive) projects. Fetherston’s treatment of Davidson’s involvement in the revitalization of the idea of a tunnel is more developed than most episodes in the book, and it makes for one of the more interesting aspects of the story.

Perhaps “The Chunnel’s” most sustained theme lies in Fetherston’s describing and explaining the differences between the English and French and how they dreamed, planned and executed the Channel tunnel. Fetherston makes clear not only the educational and cultural distinctions between British and French engineers but also the technical distinctions between their machinery and techniques. He describes how British workmen changed in private labyrinthine locker rooms, whereas the French used a large open room known as the salle des pendus, the hall of the hanged men, so named because clothes and belongings were hung on chains that passed through pulleys and could be raised to the high ceiling and locked in place. Throughout “The Chunnel,” Fetherston reveals other fascinating cultural differences, ranging from the nature of the workers’ dress to their use of cigarettes.

Otherwise, however, reading “The Chunnel” is like tunneling for 20-odd miles: It can be tedious. Fetherston might have helped orient the reader by adding chapter titles and anticipating the story’s action and suspense a little more, as Nattrass did for the tunnel machine operators. As “The Chunnel” is constructed--except for the first chapter, which describes the breakthrough joining of the tunnels dug by the British and French crews--the book takes the reader headlong into the darkness without a narrative work light. There is little piston relief between the chapters, and when Frank Davidson reappears on the last page of the book’s epilogue, more than one reader is likely to be surprised; Davidson was nowhere to be seen for about 200 pages.

“The Chunnel” is not the equal of McCullough’s “Path Between the Seas,” but Fetherston has written a book that deserves to be read. It conveys the complexity of large engineering projects in a way that few books have. One can wish that he had only had more concern for the reading comfort of his passengers and less tunnel vision in telling the story of a project that is to the end of the 20th century what the Panama Canal was to the beginning.