Southwest Pass Lighthouse built in 1965 Photograph courtesy U.S. Coast Guard

After winding its way south through America’s heartland, the Mississippi River separates into many channels before reaching the Gulf of Mexico. Today, the primary shipping channel is Southwest Pass. Marking the entrance to this pass is the most modern major light on the gulf, which consists of a six-sided, two-story building, with a smaller but similarly shaped tower projecting upward from its center. This superstructure, along with a boat dock and a helicopter landing pad, rests on a lattice of concrete pilings anchored in the floor of the gulf.

Like South Pass to the east, Southwest Pass has been served by several lighthouses, and its first tower was also built by Winslow Lewis. Lewis’ sixty-five-foot conical tower at Southwest Pass was put into service on April 18, 1832. Two unique features helped mariners identify this lighthouse: a daymark consisting of vertical black bands, and three windows built into the seaward side of the tower below the lantern room from which additional lights were exhibited. Unfortunately, the lower lamps were not properly ventilated, and the soot rose in the tower, blackened the glass planes in the lantern room, and added to the keeper’s workload.

During its first year of service, the Southwest Pass lighthouse was threatened by erosion. Measures to retard the encroachment of the river failed, and by April of 1837, the tower stood in ten feet of water. Later that year the tower toppled over and disappeared. This didn’t prevent a dutiful and resourceful keeper from exhibiting a light. A lantern was soon mounted from a tall pole, and the keeper continued his service, having only a small, squat hut for shelter.

The following year, Congress allocated funds for a replacement tower. The new tower inherited the same vertical markings of its predecessor, and was outfitted with two bay windows, which protruded from the gulf side of the tower, twenty-five feet below the lantern room. The windows held additional lamps, and as a mariner approached from the gulf aligned with the proper channel, the lights from the lantern room and the two bay windows formed a triangle.

Contractors from Massachusetts were selected to erect this second tower, and to oversee the work, the Treasury Department appointed Isaiah W.P. Lewis, nephew of Winslow Lewis. I.W.P. harassed the contractors and forced modifications to the foundation, which resulted in the tower becoming unstable after reaching a height of just twenty feet. I.W.P. was promptly removed from the site, and the contractors began anew on the tower, following a design by Winslow Lewis.

Not long after its completion, one side of the tower settled into the spongy land, leaving the tower five feet out of plumb. By 1850, the leaning tower was standing in a foot of water, and the Lighthouse Board was motivated to start planning for yet another tower at Southwest Pass. Difficulties in securing funding and the outbreak of the Civil War delayed work on a new tower for years. In the interim, the water surrounding the brick tower steadily rose.

In 1861, Keeper Manuel Moreno complained that both the tower and dwelling were flooded, and that flotsam was jeopardizing the structures. Informed of the ongoing Civil War by reports from river traffic, Moreno was also concerned for his own well-being. He pleaded for weapons to defend himself, and when the Union blockade was established at the delta, Moreno,loyal to the South, shielded the light so it could only be seen from upstream. On the morning of July 5 1861, armed Union forces landed at the station and removed the lens from the lighthouse. Moreno was left without a light, and was soon without a job, as all keepers in the area were discharged. After the delta region was secured by the Union, the tower was activated again.

Following the war, the Lighthouse Board renewed its petition for funds to replace the tower at Southwest Pass. Congress approved the request, and work began in 1870. Rather than construct a third brick tower at the pass, the new design called for a skeleton, metal tower. The spindly structure would be lighter in weight and disperse that weight over a wider foundation, hopefully allowing the tower to overcome the problems that plagued the previous towers. The tower’s central cylindrical spine was surrounded by a two-story dwelling at the base and eight lengthy supporting columns tied together with a web of iron rods. The tower was placed one half mile from the brick tower and secured to a foundation built on 185 piles driven to a depth of thirty-three feet. The new light, which was shown from a focal plane of 128 feet, was first activated on July 1, 1873.

On May 22, 1894, a conflagration erupted in the dwelling portion of the tower. When the fire reached the central cylinder, a rising column of air fanned the flames, which intensified the heat causing the iron spiral staircase to melt. The lantern room and entire central column had to be replaced.

In 1929, a light and fog signal were established at the end of the east jetty, which was constructed at the entrance to the pass. The jetty light was upgraded to serve as the primary entrance light in 1953. It performed this function until 1965, when the modern tower was placed in the waters just off the jetties. This substantial structure was in service until the fall of 2007 when it was demolished and replaced by a skeletal tower perched atop a platform supported by three steel piles.

Today, three of the lighthouses that have served Southwest Pass remain standing. Ships can readily see the evolution of lighthouse construction as they pass the stub of a brick tower, an iron skeleton tower, and a modern automated tower all found near the entrance to Southwest Pass.

References

1. Lighthouses, Lightships, and the Gulf of Mexico, David Cipra, 1997.