World War II-era telephone line still in use in Upper Tanana Valley

A portion of the Alaska Military Telephone Line along the Alaska Highway near the Canadian border

The Alaska Highway, built in 1942, was not the only World War II-era construction project linking Alaska with the rest of North America. The Alaska Military Telephone Line (AMTL), stretching 2,020 miles from Edmonton, Alberta, to Fairbanks was also built during that period.

According to the book U.S. Army In World War II; The Signal Corps, The Test, three communications technologies were incorporated into the project: radio, telephone and teletype. Radio, the most portable, followed Alaska Highway construction crews into the field. However, because of atmospheric and magnetic interference at higher latitudes, radio was not always reliable. Consequently, a telephone and teletype line paralleling the highway was also planned.

Because of wartime demands, U.S. Army Signal Corps personnel (normally responsible for building such systems) were needed elsewhere and could not be spared for the project. Private contractors built much of the line.

The line was approved for construction in June 1942. However, planning consumed the next five months and work could not start until November, about the time the Alaska Highway officially opened.

The first section of AMTL, from Edmonton to Dawson Creek, British Columbia, was perhaps the most difficult to build. Frigid winter conditions meant workers had to bore holes in frozen soil to install poles. Crews were also missing crucial supplies. For instance, 400 miles of poles were installed before crews received crossbars on which to attach the wire.

There were also unanticipated design changes. During World War II copper was designated a strategic raw material, and the War Production Board disapproved the use of all-copper wire for the AMTL, substituting copper-clad steel wire instead. The substituted wire did not provide the same long-distance transmission characteristics, so additional repeater stations were needed.

Myriad other problems delayed construction, including lumber shortages, freak weather conditions, and lack of worker housing. To meet a Dec. 1 deadline for getting the first section operational, only a skeletal system was installed (which required augmentation before proceeding further).

The schedule called for completing the next section, as far as Whitehorse, Yukon Territory by May 1. Correcting deficiencies in the original line, as well as the winter-time construction, slowed line-work considerably. By the end of January 1943, it became evident that the only way to ensure the project’s timely completion was to bring in Signal Corps troops. On March 1, the 255th Signal Construction Company left San Francisco. Corps of Engineer troops were temporarily pressed into service until the Signal Corp troops arrived.

The second section was completed three weeks later than anticipated, on May 22. On that day a call was placed over the line from Whitehorse to Washington D.C..

In early summer 1943 work started on the final section. Weather was favorable and work progressed rapidly along most of the route. There was one 50-mile stretch of particularly bad road just east of the Canada border, however. Corps of Engineer crews had punched through that road section during the previous winter when the ground was frozen. Troops had simply scraped off the insulating muskeg and graded the underlying frozen ground. When the ground thawed in the spring the road became a seemingly bottomless bog. It took a 20-man Signal Corps detachment, supplied by horseback, four weeks to put in that section of line.

By the middle of October 1943 the line was completed. Ken Coates book, North to Alaska, mentions that 95,000 poles and 14,000 miles of wire were used in the project.

Sections of the World War II-era line, some with poles tilting at crazy angles, can still be seen along the Alaska Highway in the Upper Tanana River Valley. Portions of the line are still used for local telephone service.

Sources:

• Getting the Message Through, A Branch History of the U.S. Army Signal Corps. Rebecca Raines. Center of Military History. 2011

• North to Alaska, Fifty Years of the World’s Most Remarkable Highway. Ken Coates. University of Alaska Press. 1992

• U.S. Army in World War II: The Signal Corps: The Test. George Thompson et al. Center of Military History. 2003