Chapter 3 - The Seawall Chronicles
Jun 02, 2019 11:47PM
With the financing securely in place for both the construction of the Seawall and the subsequent grade-raising, construction commenced on the first phase of the plan devised by the Board of Engineers. The wall against the sea would begin at the intersection of 8th Street and the Harbor, run south to the Gulf, then curve gently toward the west and run continuously from there to 39th Street.
Thus in preparation, four sets of railroad tracks were laid along this proposed route in order to facilitate the delivery of materials to the work sites. In just under two years this short stretch of track would convey 5,200 loads of crushed granite, 1,800 loads of sand, 3,700 loads of granite riprap, 4,000 loads of wooden sheet pilings, and 1,000 loads of concrete.
On October 27, 1902, the first piling was driven into place at 16th Street, and the Seawall’s foundation would be completed in its entirety before construction on the upper portion began.
Per the board’s instructions, the foundation measured sixteen feet wide and consisted of a total of seven parallel rows of pilings that would be driven into the ground along the line of the future wall. Four of these rows, set three and a half feet apart, consisted of round piles made of Texas yellow pine from Beaumont, each approximately one foot across and 42 feet long.
Behind the row of pilings closest to the beach side, three tight rows of 24-foot planks were also put in place by the pile driver to reinforce round pilings and to help prevent the undermining of the wall. Each piece of piling, whether round or rectangular, took roughly twenty minutes to drive into place.
Four machines manned by ten men apiece worked continuously and only stopped when either the dark or the weather prevented it. Other workers followed behind the pile drivers and dug three-foot trenches around the pilings which were then filled with concrete made from a mixture of crushed granite, cement, sand, and water.
Massive cement mixers were placed on platforms with wheeled feet that bridged the sixteen foot span of the foundation. They were then manually pushed along the foundation to efficiently deposit the concrete directly into the trenches below.
While the foundation was nearing completion, loads of granite riprap began to arrive from a quarry west of Austin, over 200 miles away. The instructions for selecting the granite were specific: one-fifth were to weigh in excess of 1,000 pounds, and at least half were required to weigh a minimum of 200 pounds, and they were to be placed along the toe of the Seawall to form an apron of rock between the wall and the beach.
Once the Seawall was complete the riprap would diminish the force of the waves on the wall and prevent the erosion of the beaches, but in the meantime it was used to anchor the wooden structures that would frame the upper portion of the wall.
Rising seventeen feet above the foundation with a concave face, this upper portion was the final step in the construction of the Seawall. Large wooden forms in the shape of the wall were hammered into place and steadied by beams braced against the large pieces of granite riprap, then they were filled with concrete.
The concrete mixer used for the upper portion of the wall was more than twice the size of the mixer used for the foundation, it even towered above the seventeen foot frame. Two mechanical arms stretched out from either side of the mixer- one arm moved the ingredients of the concrete from the railcars into the mixer, and the other arm swung the other direction toward the wall, dumping the fresh concrete into the frame.
Since the concrete took seven days to dry, and in an effort to prevent damage as the concrete settled, the upper wall was built sixty feet at a time, with tongue-and-groove joints built into the interior of each section to reinforce their connection. Working at a rate of one section per day, seven alternating, sixty-foot sections were completed at a time, and then workers would backtrack and fill in the ones in between.
This method of construction was also implemented to ensure the future integrity of the wall, making it flexible and giving it the ability to absorb the natural contractions and expansions that were bound to occur over time.
The original portion of the Seawall was completed on July 29, 1904, a mere twenty-one months from the day construction began. It extended nearly eighteen thousand feet, or just under three and a half miles, and it weighed an estimated forty thousand pounds per foot. Almost immediately upon completion it became a Galveston attraction all of its own, as people were eager to promenade along the magnificent sidewalk.
But even before the first person took an elevated stroll along the Gulf shoreline, Galveston had already come face to face with the impending reality of step two, the grade-raising. There was no turning back now; without elevating the grade Galveston was effectively inside of a bowl and any significant storm surge would be even deadlier than the one that inspired the wall’s construction.The Island’s position on the water was more vulnerable than ever, and the ingenuity and genius it was going to take to finish this task had yet to be discovered.