For thousands of years sailors have chosen the best areas for transit and commerce. These areas have become our modern ports and harbors.
In many areas new port infrastructure was simply built right on top of the old structures. This is a workable strategy in areas where the bedrock lifts cleanly out of the sea to form a solid foundation. The cultures of the Mediterranean and Aegean Seas were able to fashion durable ports from their geology. Some of these ancient ports are still visible today.
When settlers reached the new world they found few natural ports but a vast quantity of margin lands. Much of Chesapeake Bay was described as “marshy” by early accounts. The James River, the Mississippi River, and later parts of the Great Lakes would earn a similar or possibly more derogatory description.
Industrial Age Port Facilities
In the United States we built our ports much like our European cousins during the industrial boom of the late nineteenth and early twentieth centuries.
Waterways were the roads of serious commerce since the routes over land were unsuitable for the heavy volume of cargo brought by the expanding economy. Cities grew up around these areas and larger structures were built to accommodate transfer and storage of cargo.
In many cases timber was the cheapest material to construct these facilities. Large tree trunks treated with pine or petroleum tar were driven into the soft shore side and riverfront soils to support the enormous weight of the structures above.
Ports: The Second Generation
The First World War led to a weakening of isolationist ideals that gripped much of the world including the U.S. Now there was a need to move goods and commodities at an increased rate to supply troops and markets overseas.
By this time the generation of sail had stepped aside for the generation of steam and streamlining. Steel hulled vessels were much harder on dock surfaces since much more force is generated by a heavier vessel even if it is moving at the same speed. The inertia would splinter the wooden face and break piles.
Concrete was making a popular resurgence at the turn of the century and it was deemed the best material for new port facilities. In Europe ports were constructed of traditional materials since concrete was expensive and the costs of war had taken their toll. The newest concrete building technology was ferro-concrete which incorporated a steel skeleton to balance the effects of the brittle concrete. Together steel and concrete resisted bending and compression. This method, which has many steps and uses expensive materials, was out of reach for all but the most robust economies.
Since the best locations were already occupied by the existing port it must have seemed simple to demolish one and build on top of the remains.
The Common Port Problem
This is where we finally get to the real root of the problem. Ports that were once built of wood resting on wooden pilings were now built of concrete and steel but usually resting on the same grid work of preserved wooden piles.
Pumps and coffer dams did allow for some more substantial footings to be placed at some high cost projects. The Brooklyn Bridge footings were constructed far below the surface of the river and engineers at the time were as eager to promote their new methods as today’s engineers are to promote their new device of the hour.
Without much oversight these many large and small ports were built. Seaports and small local commodity ports were all built in the same manner. This building continued to parallel the industrial boom in North America swelling to a frantic pace during the Second World War.
Shipping Port Facilities Today
The durable and impermeable concrete port is a problem onto itself. The surface wears very well and many of these places are permanent in the memories of at least two generations. Like mountains, we see them as static and unchanging.
In reality the soft soils along our waterways have been sneaking into deeper waters as the hard surface runoff erodes under and around seawalls, berths, abutments, and piers. What we don’t see is that the material that once encased the tops of wooden piles is now gone. Now much more weight is placed on the pilings by the concrete above.
These pilings are now exposed to air which also causes faster deterioration. Contact with air allows both aerobic and anaerobic bacteria to act on the wood and it is exposed to more extreme conditions than when buried.
These pilings will eventually fail and cause the structure to collapse or otherwise become unusable. Augmenting the structure with modern steel piles retrofitted through the existing ferro-concrete is possible but expensive. A less costly approach is using a corrugated steel panel which is driven like a pile but has interlocking edges to make a vertically stiff but horizontally flexible wall.
The iron curtain wall, as it is called, is expensive and not suited to all locations.
Replacing all of the deteriorated facilities in the U.S. would cost trillions of dollars. There is little political ambition to approach the subject so it will likely take private industry to demand action. Our demands for dredging have gone unheard for more than a decade and there is still no serious plan to solve that problem so there is little hope for our waterfronts.
Including our maritime assets in the long term discussion about aging infrastructure is essential since there will be few containers to move on the nation’s highways and railroads if our ports are not safe, modern and efficient.