20 March 2011

Streets paved with wood

From the tumblr of the Hennepin County (Minneapolis) library, via Stuff about Minneapolis:
Here is a wintry photo (please excuse the slush) of the oldest street surface in downtown Minneapolis. It is a piece of 8th Avenue North just south of Washington Avenue North. Before there was concrete, asphalt or cobblestones, downtown Minneapolis was paved with creosote soaked wood blocks. You can see the tree rings in the blocks.
This is interesting, though not rare.   A  brief search yielded similar streets in Philadelphia (Camac Street); Willliamsport, Pennsylvania; Pittsburgh, Pennsylvania (where flooding caused the blocks to swell and "burst"; Baltimore, Maryland; Victoria, British Columbia; and Berlin, Germany (and undoubtedly many hundreds more).*

The technique and technology of wood block paving is discussed at Kaswell Flooring Systems:
Timber blocks had been used as paving as early as the fourteenth century in Russia. Wood block pavements were laid in New York and Philadelphia about 1835, in England about 1838, and in Paris about 1880. The first blocks were round or hexagonal, and many different types of wooden pavements were patented between 1840 and 1913...

[In Dallas, Texas] the first blocks, which were twelve inches long and irregular in shape, were laid down without any foundation in the virgin soil, and they began to sink, each to a different depth. "About the roughest thoroughfare in the world resulted," recalled one man. "Going over it in a vehicle was as wearing as riding a camel, and the people began to beg the City Council to give them back the original black, waxy mud." Trial and error disclosed that the wooden blocks worked better if cut into uniform eight to ten inch sections and spread on a bed of six to eight inches of gravel. The spaces between the blocks were packed with sand and then covered with coal tar or pitch...

Throughout the United States a variety of woods were used for paving blocks. Soft pine and cedar predominated, although oak, cypress, hemlock, Washington red cedar, cottonwood, mesquite, Osage orange (bois d'arc), redwood, Douglas fir, tamarack, longleaf yellow pine, shortleaf pine, Norway pine, and blackgum were also utilized...

The decay of wood paving blocks is due to fungi, produced by heat, air, and moisture. Creosote, obtained by distilling coal tar, wood tar, or water-gas tar, was used to preserve the wood, especially when the blocks were to be installed in wet areas. The success of a wood pavement depends on the quality of the creosote oil, not only to preserve the wood but also so that it will neither expand nor contract...

On the subgrade, a concrete foundation was poured. A thin cushion of sand or mortar was placed on the concrete to seat the wooden blocks, which were laid with no joint more than 0.125 inch, using nothing but whole blocks. After the blocks were placed, they were rolled by a steam roller until the surface was smooth and brought to grade and contour of the finished pavement. After the blocks were thoroughly rolled, a fine sand, cement, or bituminous (coal-tar pitch, asphalt, etc.) material was used to fill the joints...

* and Chicago (nice link, hat tip to Steve), and Cleveland (hat tip andiscandis).

7 comments:

  1. There are a few left here in Chicago too. Nice little article: http://forgottenchicago.com/features/chicago-infrastructure/wood-block-alleys/

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  2. Excellent, Steve. Added to the post.

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  3. There's one (Hessler St.) left in Cleveland, too.
    http://en.wikipedia.org/wiki/Hessler_Street_Fair

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  4. I ran track in high school and one of the small towns we went to had an outdoor wood track made just like this. They were very strict about no one wearing spikes on their track. I wonder if it is still there.

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  5. The most famous one in Chicago (just South of North Ave between State and Astor) was torn up recently. I went by this weekend and there was still a small pile of uprooted blocks. The link Steve posted has an image before the blocks were removed.

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  6. Hey Minnesotastan!
    This is the second time I find your blog in the first position of my google search. You sure have interesting topics! I am trying to find old pictures of wood block paving - with limited success so far.

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    1. Yes, the blog has achieved a rather high Google Search ranking because of all the outgoing links to quality sites plus a lot of links to here from good places. Good to see you back. If you don't find enough photos on Google Images, you might try the old fashioned library catalogue search for out-of-print books. Or write to a wood industry spokesman or a wood-products company.

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