Seattle’s Digging It

“As a result of its rugged topography, the city of Seattle has a class of engineering problems peculiarly its own,” wrote George Holmes Moore. He, of course, was referring to the desires of Seattle citizens to travel more easily through the city. The only solution was to move massive amounts of dirt out of the way and create better access. Holmes’ sentence was written in March 1910. He was referring to what until Bertha bit it, or couldn’t, was Seattle’s most famous digging scheme, the regrading of Denny Hill.

As with Bertha, the removal of Denny Hill at the north end of downtown Seattle was big news across the country. The reports describe the blasting away of 5.5 million cubic yards of dirt as a beautiful thing, necessary to the survival of the city. As H. Cole Estep wrote in Industrial Magazine, “This is a tremendous task for a community so young in years; but the citizens, having an abiding faith that Seattle is destined to become the New York of the Pacific coast, have taxed themselves cheerfully and heavily in order to finance the undertaking.” Sound familiar? All we need to do is a bit of landscape rejiggering and Seattle will be a world class city. It didn’t happen then.

Most citizens did not actually tax themselves. Only those affected by regrade projects had to pay. They did so through what were known as Local Improvement Districts, where those who owned land in the regrade area paid for the project because they were the ones who would benefit the most by the increased value of their post-regrade property. How much each property owner had to pay was determined by a three-person commission, which, as one can imagine, led to a few issues involving the courts.

Those early landscape remodelers ran into a few underground issues too. Their technology of choice was water, using hydraulic hoses, or giants, to wash away the hills. When they encountered small objects, such as buried forests, mammoth teeth, or once, a suspected meteorite that probably was just a boulder, they would stop and pluck it out, but when they ran into more obstinate objects—usually dense lenses of fine grained sediment—they would turn to the old reliable dynamite, blast the offender to bits, and continue remove the dirt. They had it a lot simpler back then.

Despite cost overruns, lawsuits, deaths, and delays, the city completed the major regrade projects, giving Seattle a new face. I suspect that Bertha will eventually get back on track too but it always amazes me how history repeats itself.

And because my momma done told me to, I am including a link to a story in the New York Times about Bertha.

 

 

Dreaming of Tunnels in Seattle

Bertha and her travails got me thinking about Seattle’s long history of tunneling and tunnel plans. In an article by Red Robinson, Edward Cox, and Martin Dirks, the authors wrote that over the past century or so, “more than 100 tunnels totalling over 40 miles” have been excavated in Seattle. These include sewers, railroads, water lines, landslide stabilization, and busses. The earliest dates back to the 1880s.

What they don’t mention are the numerous tunnels proposed but never built including ones under First Hill, Denny Hill, and Beacon Hill.

Here is a very short list of some of those that were built and those that merely were dreams.

1. Great Northern Tunnel – 1903-1905 – The 5,141-foot-long tunnel allowed trains to bypass Railroad Avenue and drop passengers at the Great Northern’s new Union Depot (later called King Street Station), being built out into the tidelands at the south end of downtown. The tunnel was built from either end, into the center. The crews met on October 26, 1904, Along the way, they had encountered a forest of buried trees. They also had a few troubles, including buildings settling as the tunnel went beneath them. One of them, the York Hotel (also known as the Ripley) sustained so much damage that the Great Northern bought it and leveled it. Seattleites liked to joke that it was the longest tunnel in the world as it went from Virginia to Washington…streets.

2. North Trunk Sewer -1908-1914 – Prompted by a fears of cholera and typhoid, the city built almost 22 miles of sewer tunnel, mostly in the northend, including one of the longest sections, the 3,500 tunnel under Ravenna Creek from its former outlet at Green Lake to the University Village. Workers started with a shielded boring machine but it was not able to cope with the soil conditions so ultimately the tunnel was dug by hand. The tunnel failed in Novembr 1957, creating a massive sinkhole at 16th Ave. N. and NE Ravenna Boulevard.

Sinkhole on Ravenna in 1957 - from Seattle Times

Tunnels that never made it.

1. Denny Hill Tunnel – 1890 – L.H. Griffiths, developer of Fremont, proposed a tunnel under Denny Hill to make it easier to reach his development. It was stopped though several years later, Thomas Burke, a leading opponent of the tunnel, suggested it should have been built.

2. Jackson Hill Tunnel – 1904 –In early 1904, residents requested the city to excavate a tunnel through Jackson from Fifth to Twelth avenues. After a careful investigation, city engineer R.H. Thomson rejected the idea and convinced proponents that it would be better to eliminate the high ridge.

Great Northern through Beacon Hill - From Seattle Times

3. Beacon Hill – 1902 – Great Northern proposes to enter Seattle by tunneling under Beacon Hill.

4. First Hill – 1903, 1908, and 1929 – Various groups over the years proposed tunneling under First Hill to access the valley beyond and also to access Second Hill.

First HIll Tunnel plans - From Seattle Times

5. Bogue Tunnels – In 1911, engineer Virgil Bogue presented a grand transportation and city plan for Seattle. His proposed tunnels included Day Street in southeast Seattle, and ones under parts of First Hill, West Seattle, Interlaken, Spokane Street, and Blanchard Street, as well as railroad tunnels under Beacon Hill, Wedgwood/View Ridge, and downtown Seattle.

Material for for this story comes out of research I have done for my new book on Seattle – Too High and Too Steep: Reshaping Seattle’s Topography.

If you so desire, you can like my geologywriter Facebook page.