Monday, August 08, 2011

Cordova's Million Dollar Bridge





From Wikipedia:
The Miles Glacier Bridge, also known as the Million Dollar Bridge, was built in the early 1900s fifty miles from Cordova in what is now the U.S. state of Alaska. It is a multiple-span Pennsylvania-truss bridge which completed a 196-mile (315 km) railroad line for the Copper River and Northwestern Railway, built by J. P. Morgan and the Guggenheim family to haul copper from the old mining town of Kennicott, now located within the Wrangell - St Elias National Park and Preserve, to the port of Cordova. It earned its nickname because of its $1.4 million cost, well recouped by the about $200 million worth of copper ore which was shipped as a result of its construction.

We walked through the brushy trail from the Child's Glacier .8 miles, according to the sign, loudly alerting any bears that we were just walking through. 





Forest Service signs gave us some sense of the difficulties they had building the bridge. They had to build these caissons so the men could work below the water.


The Miles Glacier was much closer then and threatened the bridge.  Ned Rozell wrote in a 2002 Alaska Science Forum:

Glaciers stuck out their tongues in defiance along the entire route, but the pull of financial gain and human ingenuity overcame them. In one case, workers laid tracks across the debris-covered ice of Allen Glacier for five-and-one-half miles, according to my two sources for this column, The Copper Spike by Lone Janson and Iron Rails to Alaskan Copper by Alfred Quinn.
Miles Glacier from the bridge July 2011
Two of the largest obstacles on the route were Miles and Childs glaciers, both of which calve icebergs into the Copper River from opposite banks. Erastus Hawkins, the engineer in charge of the railroad project, and Michael Heney, the construction contractor, preferred to run the railroad alongside the Copper River, but the Miles and Childs glaciers sprawl over both shorelines at a pinch-point about 15 miles from the river's mouth. Not listening to other engineers who thought the problem was insurmountable, Hawkins designed a 1,550-foot steel bridge to span the Copper River at a river bend between the two glaciers.
Child's Glacier from the bridge July 2011
Geologists had found that the glaciers had fused during the past several centuries, and the leader of a U.S. Army expedition up the Copper River in 1885 reported that the nose of Miles Glacier was then about 120 yards from the site of the bridge. By 1908, both glaciers had receded to provide a gap of about three miles.
Starting in April 1909, workers scrambled to complete the Million Dollar Bridge, spurred on by a U.S. law that gave railroad developers four years to complete a designated route. After four years, the government would tax them $100 per operating mile per year. Contactors finished the bridge by midsummer of 1910.
Soon after construction of the Million Dollar Bridge (which cost $1.4 million to build), the glaciers threatened the railroad.
Workers Who Built the Bridge
In August 1910, two glaciologists from the National Geographic Society studied the sudden advances of both Miles and Childs glaciers. A northern lobe of Childs Glacier began creeping toward the bridge in June, and by August it was moving eight feet per day. On August 17th, the 200-foot face of the glacier was 1,624 feet away from the bridge.
Ralph Tarr, one of the glaciologists, speculated on what would happen if the glacier continued to advance in 1911.
"It is absolutely certain that no corps of engineers could save the bridge and railway if the glacier should advance that far," he wrote.
Childs Glacier did not engulf the bridge, but the glacier crept to within 1,475 feet in June 1911. Childs and Miles glaciers have since retreated, sparing the Million Dollar Bridge, which served the railway from 1910 until 1938, when low copper prices forced the shutdown of the Copper River and Northwestern Railway. The bridge survived nature's whims until March 27, 1964, when the Good Friday Earthquake knocked the northernmost span from its concrete piling.
 As noted in a previous post, the Child's Glacier today is advancing 500 feet a year according to the Forest Service signs.  













As you probably can see, we walked across.  But there were cars going across too and someone said the road goes another 8 miles or so. 

3 comments:

  1. Beautiful bridge! Other thing for the next time.
    Very interesting post, Steve.

    ReplyDelete
  2. My great uncle worked in Alaska from 1908-10. He was in the Army Corps of Engineers at a later date, don't know if he was at the time of the bridge being built, but I just re-read a letter from 1960 where he explained working a project and camping on either side of the river with miles and childs glaciers. He drew a little sketch, too.

    ReplyDelete
  3. Carolyn, that's really cool. A reason NOT to throw everything away. Can you send me the sketch? I'll put it up. My email's in the right hand column above the blog archive. (You got the comment up twice, so I deleted one of them.)

    ReplyDelete

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