Mississippi River Lighthouse - Frank's Island, Louisiana - 1820

Mississippi River Lighthouse - Frank's Island, Louisiana - 1820
Architectural Drawing by Henry Latrobe - 1817 - National Archives

A Brief History of the Frank's Island Lighthouse

In 1804, President Thomas Jefferson, having recently purchased the Louisiana Territory, envisioned a grand monument to serve as a navigational beacon to mark the entrance of the mighty Mississippi River. Benjamin Henry Latrobe, the renowned architect and engineer, was selected to design such a lighthouse. On paper, Latrobe’s “Lighthouse at the Mouth of the Mississippi River” was magnificent! The building materials consisted of brick, marble, and other stone; but the foundation of this heavy structure would have to be laid upon the soft clay that lines the entrances of the Mississippi River.

The site chosen for the lighthouse was a small island located north of the Northeast Pass of the Mississippi River called Frank’s Island. Although engineers determined the soil of the island to be adequate for the structure, no contractor at the time was willing to undertake such a foreboding task. After some prodding, the designer of American lighthouse reflector systems of the day, Winslow Lewis, finally accepted the challenge; but only under certain contractual terms – Congress agreed that he would be paid in full should the structure’s foundation fail. Finally, in 1818, construction on the lighthouse began.

In March of 1820, just days before the lighthouse was to be completed, the foundation settled and cracks began to form throughout the structure. The internal arches could no longer support the massive weight of the stone parapet. The columns fell to the ground and the walls of the Keepers Quarters collapsed. Without any support at its base, the lighthouse tower began to list. Deemed too costly to repair, the lackluster remains of what was to have been a magnificent structure were abandoned.

After spending over $85,500, a tidy sum in those days, and with no lighthouse to mark the entrance of the Mississippi River, Congress once again turned to Winslow Lewis, who made an offer they could not refuse. For just under $10,000, Lewis offered to build a second lighthouse on Frank’s Island and guarantee its foundation. On March 20, 1823, the lantern was lighted for the first time at the Northeast Pass Lighthouse. Lewis’ lighthouse served as a working navigational beacon until 1856. Over time, the lantern gallery was destroyed and the tower was in disrepair. By the 1950’s Frank’s Island itself eroded away and the lantern-less tower stood alone in the waters of Blind Bay. In 2002, encroached by the powers of a hurricane, the ruins of the second lighthouse fell over into the water. Unless the tides are extremely low, no sign of either lighthouse erected on Frank’s Island remains today…

Frank's Island Lighthouse - 1823

Frank's Island Lighthouse - 1823
Concept drawing of Winslow Lewis' lighthouse by author using scale drawing of tower by Samuel Wilson, Jr.

Friday, August 21, 2009

"The Weight" - Winslow Lewis’ Validation of Benjamin Latrobe’s Design for a Lighthouse at the Mouth of the Mississippi River

There is an underlying tone contained within this blog that demonstrates a lack of faith in the design, engineering, and construction abilities of Winslow Lewis. Even researchers who feel Lewis was “the right man at the right time”, such as Richard W. Updike, make these assertions with a certain lack of conviction. No matter what opinion one may have of Winslow Lewis, he did accomplish what was thought to be impossible… He was able construct a stable masonry lighthouse structure on the soft soil of the Mississippi River Delta. What makes this achievement more impressive is the fact that he went before Congress and guaranteed that he could do so despite Latrobe’s apparent failure to achieve the same. As a further credit to Lewis in these endeavors, he was able to repeat his success; but not without some failures in between.

The 1823 Frank’s Island Lighthouse stood for 179 years before it collapsed. It had sunken about 3 to 4 feet at the time it was surveyed by Samuel Wilson, Jr.; but it served its purpose without failure or disappointment until it was discontinued in 1856. Between 1831 and 1840, Lewis constructed several other lighthouses on the Mississippi River Delta. These challenges were met with very limited success. Towers at the South and Southwest Passes were undermined by water currents and collapsed. The only other success Lewis had with constructing a masonry lighthouse on the Mississippi Delta is the 1840 Southwest Pass Lighthouse. Even though the tower of this lighthouse was 10 feet shorter than that of the Frank’s Island Lighthouse, the second Southwest Pass Lighthouse began to list shortly after construction. Despite this flaw and a rather disappointing service record, the structure is still standing after 169 years.

Due to the mixed successes and failures of Lewis’ masonry towers on the Mississippi Delta, one could reasonably question whether his success with the Frank’s Island Lighthouse was a fluke. If Winslow Lewis truly knew how to erect a masonry tower on alluvium soil, why could he not faithfully duplicate his earlier success? The Frank’s Island Lighthouse tower was 75 feet tall – at least 10 feet taller than any of the other masonry towers he built along the Mississippi. Therefore, it was the heaviest of the lot. Even though weight was his major concern and criticism with Latrobe’s Lighthouse, Lewis achieved his greatest success in the area with the largest and heaviest structure he built. What kind of foundation did Lewis choose to erect the 1823 Lighthouse? Did he possibly borrow from Latrobe's foundation design, but chose to get it right the second time around? One may never be able to answer these questions without excavating the site now six or so feet under water. The only reference I could find relating to a foundation specification for one of these masonry lighthouses is taken from David Cipra's "Lighthouses & Lightships of the Northern Gulf of Mexico" regarding the original Southwest Pass Lighthouse...

"In 1842, a Congressman charged that the first tower was shoddily built 'on a foundation of old flatboat planks at a cost of $10,011.74' The construction contract had called for a foundation of pilings driven 40 feet, or as far as a 1,400-pound weight falling 26 feet could pound them."

I can only assume that Congress would have specified a foundation based on that of the proven 1823 tower’s design. It would also seem that Lewis’ limited success with these structures may have been hindered by his propensity to take shortcuts as he did with Latrobe’s Lighthouse. Regardless of his haphazard efforts, Lewis did get it right the first time, and this is where Lewis, himself, has inadvertently validated Latrobe’s lighthouse design…

What are you supposed to do if you are walking on the surface of a frozen pond and the ice begins to crack under your feet? You are supposed to lie down and spread your weight across as much of the ice’s surface as you can. By lying down on the ice, do you weigh less? No, you weigh the same; but by lying down, your weight is no longer concentrated within the area of your feet. Instead, it is spread across the entire area of your body. By spreading your weight, you are exerting less pressure across the overall surface of the ice. This is the same thought process that Benjamin Latrobe used in designing his lighthouse. On page 246 of the article, “Benjamin Latrobe’s Designs for a Lighthouse at the Mouth of the Mississippi River”, Dr. Michael W. Fazio offers an extensive analysis of the efforts Latrobe made to lighten the structure and to spread its weight over as large an area as possible. According to the article (Footnote 68), “The area of a 108-ft. diameter circle is 9156 sq. ft. A reasonable pile-mat bearing capacity for the blue clay soil would be about 1500 pounds per square foot; therefore 9156 sq. ft. times 1500 lbs. per sq. ft. equals 13,734,360 pounds, the allowable load that the pile-mat should have supported… If an average weight for the brick and stone masonry is assumed to be 150 pounds per cubic foot, then the total weight of the lighthouse was 36,000 cu. ft. times 150 lbs. per cu. ft. equals 5,400,000 pounds – well below the allowable load. Ruddock, in his report, said that the tower had a masonry volume of 24,667 cu. ft. and weighed 3,154,625 pounds.” Using Dr. Fazio’s analysis, one can divide the weight of Latrobe’s Lighthouse (3,154,625 pounds) into the load bearing capacity of the soil its weight was spread across (13,734,360 pounds) and conclude that the structure came in at only 23% of the soil’s load bearing capacity. Based on this analysis alone, it should be evident that weight was not cause of the structure’s failure.

Now, if one applies the same analysis to Lewis’ lighthouse, a different result comes to light. A truncated cone with a lower diameter of 28 feet, an upper diameter of 22 feet, and a height of 75 feet, has a volume of 37,000 cubic feet. Wilson's survey drawing indicates that Lewis' tower had two 18-inch thick brick walls, one inside the other with a 1-foot space in between. My conservative approximation would suggest that the tower was 25% solid, yielding a masonry volume of 9,250 cubic feet. The masonry weight of the tower would be approximately 1,387,500 pounds. Although the base of the lighthouse was 28 feet in diameter, let's assume that it sat on a foundation platform that measured 30 feet in diameter – less than 1/3rd. the diameter of Latrobe’s structure. This would yield a base surface area of 707 square feet, resulting load bearing capacity of 1,060,500 pounds. If my calculations are even remotely correct, then Lewis' tower weighed 327,000 pounds or 31% over the load capacity of the strata it sat upon! Even though Lewis’s lighthouse weighed about 1/3rd. less than Latrobe’s lighthouse, its weight was spread over a much smaller surface area. Perhaps this is why the structure had sunken 3 to 4 feet over the course of 111 years. However, if weight was the key flaw in Latrobe’s design, then Lewis’ lighthouse should have met a similar fate in as short a time. Instead, his tower, which exceeded the load bearing capacity of the soil it sat upon by 31%, continued to stand for 179 years. Winslow Lewis, through the success of his 1823 lighthouse, proved that it was not the weight of Latrobe's lighthouse which caused its untimely failure!

Friday, March 6, 2009

Aftermath of the Collapse

In a letter to the Secretary of the Treasury dated June 6, 1820, the Attorney General, William Wirt, expressed his opinion which diminished the responsibility that Winslow Lewis, et al, may have had in the failure of the first lighthouse erected on Frank’s Island. Here is the opinion in its entirety:


The contractor to build a light-house at the mouth of the Mississippi is not answerable for the failure of the foundation unless the choice of the same were left to himself.

June 6, 1820.
Sir: If the undertaker to build a light-house at the mouth of the Mississippi had contracted to build a house of particular dimensions, the choice of the foundation being left to himself, he would have been bound to have made a sufficient foundation to support the building, and would have been answerable in damages if it had failed. But, inasmuch as in the contract with Winslow Lewis the United States specify the particular foundation which they will have, I am of the opinion that, if the contractor complied faithfully with this specification in laying the foundation, he is not answerable for its failure. In this case, if either party is to be considered the insurer of the foundation, it is the party who made the selection – to wit, the United States; and the undertaker would, I think, in a suit against him, be permitted to retain so much of the advance as would cover the cost of the materials and labor furnished by him towards the work, so far as it went.
If, on the contrary, the foundation was not that for which the United States stipulated, then the undertaker is answerable on this bond, and would be forced not merely to refund the advance which he received, but to answer in damages for the breach of his undertaking.
I have the honor, &c., &c., &c.,


To the Secretary of the Treasury.

In this opinion, the Honorable William Wirt clearly leans towards the United States (and in de facto, Benjamin Henry Latrobe) as being to blame for the foundation’s failure since the specifications for the foundation were clearly defined within the contract. However, Mr. Wirt allows for a caveat that could totally overturn his opinion. If it were proven that Winslow Lewis and his sub-contractors did not follow the specifications as defined, then Winslow Lewis would be held responsible for the structure’s failure. It would appear that such evidence was never produced… Or was it???

According to the article, “Benjamin Latrobe’s Designs for a Lighthouse at the Mouth of the Mississippi River” by Michael W. Fazio, inspections of the damage and the resulting reports were corresponded over the period from April, 1820 to March, 1821. At first, these reports expressed optimism that the structure could be saved. It was clear from these reports that the “portico and keeper’s house were in ruins”. However, despite its listing, one inspector expressed hope that the tower could be saved “with proper direction from Latrobe.” But this direction never came as Benjamin Latrobe died of yellow fever on September 3, 1820. By March of 1821, another inspector, Major Jenkins “concluded that new construction would be more economical than repairs.” Without having access to these reports at this time, it is impossible for me to know whether any of these inspectors actually examined the foundation. But Dr. Fazio did locate one letter from Chew to Pleasanton, dated May 26, 1821, confirming that an inspection of the foundation had been conducted independently by an engineer named “Mr. Ruddock” from “Carolina”. Here is an excerpt of Mr. Ruddock’s report as printed in Dr Fazio’s article:

"[O]n breaking up the brick floor of the portico, I found a layer of mud, two feet thick all under the area of the same, and within the wall of the foundation, and it was evidently thrown in, by the workmen, for the purpose of saving about 59,000 bricks which by the contract should occupy the place which the mud does – under this mud, I found a layer of one foot thick, of stones and sand and some oyster shells – I thus came to the planking on the top of the timbers; and found nothing but soft mud and water, among the heads of the piles; although the contract said, the heads of the piles, among the timbers should be filled with shells or solid materials, - yet none were to be found here; I then thrust a pole two inches in diameter, down among the pilings, ten feet deep with the greatest of ease; and drew the same out again – this was done in the presence of several gentlemen who stood by and saw the whole; the water immediately rose to within two inches, of the top of the ground, being 4 feet above high water. Therefore to ascertain whether this water came from below the foundation, or whether it was lodged there by rains; I excavated a hole two feet square and 6 feet deep, in the virgin strata, at about 8 inches on the outside from where the pilings were driven – and at that depth I found no water; what I dug out, was a solid blue clay strata, that weighed 95 lbs. to the cubic foot….It therefore appears that this water was one cause of the tower sinking – another cause, of the sinking of the building, was, the workman having removed the scaffold poles too soon, before the work had gotten properly dry, and consolidated all together – The falling of the walls of the rooms, and of the parapet, and of the 20 stone pillars; was in consequence of bad work, and bad mortar – the arches were not sprung, in a proper manner; as the walls were carried up too high, before they laid off the arches – the consequence of this was, the walls at the heighth; were not sufficiently solid, and weighty to stand as butments; of the semi-arches, and when the weight of the parapet pressed upon the arches after the poles were removed, the walls split, and gave way, and consequently the whole work fell to the ground."

If we accept Mr. Ruddock’s report at face value, it is clear that Latrobe’s design for the foundation was not followed; the keeper’s house and its walls were improperly constructed; and the support scaffolding was removed too quickly. However, it is unclear from Dr. Fazio’s article just who Mr. Ruddock was and why he was qualified to draw such conclusions. A bit of research on my part found within the 1822 edition of Blunt’s American Coast Pilot establishes that Mr. Ruddock was the engineer on board the Aurora Borealis, the lightship stationed at the Northeast Pass while the second lighthouse at Frank’s Island was being constructed. (I have since submitted my findings regarding Mr. Ruddock to the USCG historian since this information also establishes that the Northeast Pass lightship was the first such vessel to be stationed outside of protected waters.) With all this in mind, it would seem that Mr. Ruddock’s report would have historically established Winslow Lewis as the individual responsible for the collapse of the first Frank’s Island Lighthouse. Unfortunately for Latrobe’s legacy, Beverly Chew, the New Orleans Collector of Customs, wrote a letter to Stephen Pleasanton accompanying Mr. Ruddock’s report stating, “that the sinking of the building cannot be attributed to the causes assigned in his report.” It seems as though the now apparent actual history of the Frank’s Island Lighthouse was skewed by Mr. Chew’s not-so-professional (in my estimation) opinion as to the cause of the structure’s failure.

As taken from Dr Fazio’s article: Ruddock concluded by saying, “Had I not have seen the necessity of interfering in this business; never should I have run myself into the trouble, expense, and hazards, that I, on this account have done, But from seeing my country fleeced of its resources; without an equivalent; by men who appear to be destitute of every moral and virtuous tie, that binds human society in union, I have felt my duty; and therefore, shall not shrink from the Task.”

It is an historical injustice that Mr. Ruddock’s report was apparently skimmed over – if not wholly disregarded. Mr. Ruddock was passionate about his findings and committed to his duty in reporting them…