Houston and Galveston celebrate a new causeway in 1939.
Old Structure Built Only 25 Years Ago; Consulting Engineer Gives General Description of Big Job.
Editor’s note: This story originally appeared on Sunday Aug. 13, 1939. It has been edited for length.
The new Galveston causeway, connecting Galveston with the mainland, exemplifies the tremendous growth and importance of automobile traffic under our presentday civilization. It has been only about 25 years since the completion of what we now call the old causeway. That structure was built to replace railway trestles and a highway bridge, all destroyed by the 1900 storm.
During that short span of 25 years has come the major automobile development, with higher speeds necessitating wide traffic lanes, and a tremendous growth in the number of vehicles in intercity automobile traffic.
Significant Change
Another significant change affecting the need for new highway traffic facilities between Galveston Island and the mainland lies in the problems of what is now known technically as “urbanism.” That term is applied to the special technical problems incident to the populations in large cities.
Twenty-five years ago, Texas had little knowledge or experience with those urban problems. Today, Texas has a number of large cities and some of those problems are becoming acutely realized. One of the principal phases of urbanism is the necessity of providing for large peak volumes of automobile traffic concentrated at certain points and at certain hours.
Another interrelated phase of urbanism is the need for the more formal types of recreation. Today the masses in a great city can find their recreation only en masse The need for the new causeway has been accentuated by these factors, resulting in congested traffic peaks of travel for use of the marvelous beach facilities at Galveston.
Forty Feet Wide
The new causeway is 40 feet wide between curbs, providing four traffic lanes each 10 feet wide. To provide a safety space for occupants of stalled cars as well as for use of pedestrians, there is a sidewalk 2½ feet wide on both sides of the bridge between curb and railing. In order to obviate possibility of out-of-control automobiles leaving the roadway, the curbs are 14 inches high, and the railings at the outer line of the sidewalk space are exceptionally massive.
The new causeway parallels the old causeway at a distance of 535 feet, equivalent to a long city block therefrom, and is on the southwesterly side. This space from the old causeway was adopted to permit adequate room for separating the approach traffic ways on both the island and mainland sides. On the mainland end, the connection to present roadways from Houston, Alvin and Texas City will cross the main line Santa Fe tracks by an overpass. On the island end the roadway to the new structure is separated from the present boulevard by modern traffic-way with parking between the two directions of traffic.
Twenty-Five Feet Above Water
The main deck of the new causeway is 25 feet above mean low water, approximately nine feet higher than the deck of the old causeway. The underside of the lowest girders is over 18 feet above mean low tide, which will clear the crests of any storm waves anticipated. The type of piers was determined to give a maximum of stability with a minimum of obstruction to storm waves and currents. The piers consist of pairs of concrete cylinders either 10 feet in diameter or nine feet in diameter in the case of one-third of the piers, sunk to depths of 25 feet to 35 feet below low water level and giving a large embedment in the bottom of the bay. In addition, each pier cylinder is further supported by a cluster of 16 to 20 piles spreading out all around at their bottoms, which are from 40 to 60 feet below the bottom of the cylinders or 60 to 85 feet below low water.
Thirty-Nine Spans
The principal length of the bridging consists of 39 three-span units of reinforced concrete girder construction. Each of these units is 201.5 feet long between the armored roadway temperature expansion joints. Each unit has a central span of 72 feet between pier centers and two flanking spans of 63 feet. At each end of the bridging is a Ushaped abutment extending back 60 feet and connecting with long wing walls to protect the ends of the approach fills. These walls are of semi-massive reinforced concrete with interior buttresses technically known as counter-forts extending back into the fills. Heavy sheet piling and riprap enclose the abutment area and the toe of the fill. These embankments will be given some type of partial protection, pending availability of funds for the expenditure necessary for constructing storm – proof walls through their length.
Crosses Coast Canal
The new causeway crosses the Intracoastal Canal extension from Galveston Bay to Corpus Christi, which is now finally under construction and undoubtedly will carry considerable traffic. The drawspan in the causeway at this canal will have a clear width of 105 feet between fenders and unlimited vertical clearance when open. The roadway is slightly raised at the drawspan to provide an under clearance of 20 feet at its center above ordinary tide level, obviating the necessity of opening the span for small boats and barges.
Sound siren and flashing warning lights placed nearly 500 feet on either side of the drawspan will give initial warning to highway traffic when the span is to be opened. Following these preliminary warning signals will be additional “slow” and “stop” signals and finally double railroad crossing gates will give further protection to traffic.
Type of Drawspan
The drawspan is of the type known as a double-leaf bascule, each half of the span raising about a pivot. With normal opening of the span, both leaves together, the decks of the drawspan leaves rise above the adjacent fixed flooring, forming barricades which make it impossible for any vehicle to run off the bridge. Normal operation of the span will be by electric motors, but in case of failure of the main power supply both leaves can be raised by auxiliary gasoline engines.
The total cost of the main crossing, exclusive of connecting roadways and the Santa Fe overpass, will approximate $2,500,000.
Of this amount, $675,000 has been contributed by the federal government and the remaining funds by the Texas highway department. The project was initiated by the highway department under the chairmanship of Harry L. Hines and Gibb Gilchrist, state highway engineer, and completed under the administration of Robert L. Bobbitt, chairman; Julian Montgomery, state highway engineer.