Opinions vary widely regarding the actual cause of the Eastland Disaster on the morning of July 24, 1915. We believe there was no single cause. Rather, we believe the Eastland capsized due to the cumulative affects of many events, beginning with its original design and construction.
The Eastland was designed and built for speed. It was a narrow ship with a very shallow draft. This caused the Eastland to be very unstable in the water, a result of its short metacentric height. In fact, the Eastland had a history of near accidents and was known as a very "cranky" and top-heavy ship. Once contructed and in service, numerous modifications were subsequently made to the Eastland. These modifications added to the top-heaviness of the ship and made it less stable in the water. Lastly, the ballast system may not have been adequate, and the maximum passenger capacity may have been exceeded.
So it really was not a matter of if the Eastland would capsize, it was simply a matter of when. Essentially, it was a disaster waiting to happen.
DESIGN & CONSTRUCTION
With initial plans to carry fruit as well as passengers between South Haven, Michigan, and Chicago, Illinois, the design of the Eastland was influenced by the shallowness of the harbor at South Haven. The Eastland was to be loaded in the Black River in roughly twelve feet of water and would have to cross a bar where the depth of the water was also approximately twelve feet.
The Michigan Steamship Company was one of two companies that desired to run a steamship service between South Haven and Chicago. Both companies wanted to christen their new vessels as the "City of South Haven." The ship to be launched first would be entitled to secure the name.
The Eastland was designed and built with a very short metacentric height. This is likely the most significant factor in causing the Eastland Disaster.Although the Jenks Ship Building Company had a successful track record as a business, the Eastland was, in fact, the first and only passenger ship built by Jenks. With the exception of the Eastland, Jenks built freighters exclusively. (Note, freighters carry a more stable load, compared to passenger-carrying steamliners where the load of the passengers could shift while en route.)
The initial engineering designs called for a short metacentric height. This was based upon the assumptions of building a ship that was fast in the water, requiring a shallow draft, to be carrying freight.
After the metacentric height was determined during the engineering and design, 60 feet of length was removed from the Eastland (thereby making it less buoyant); it was also built with one additional deck (thereby making it more top heavy).
No tests were performed by the builders or the inspectors to calculate the actual metacentric height of the Eastland until years after the disaster.
Several physical modifications were made to the Eastland over the years prior to the disaster, which likely shortened the metacentric height even further from its initial design and construction.
The five gangways on each side of the Eastland were built relatively low on the ship. When the Eastland was not loaded with passengers and freight, the gangways were approximately four feet above the waterline. When loaded with passengers and freight, the gangways were approximately 20" - 24" inches above the waterline, at times as little as 12" to 14". When the Eastland would list - as was reported on several occasions - water frequently spilled over onto the main deck. (And when the Eastland capsized, the water that entered the ship on the port side added to the weight on the port side, likely accelerating the list to port and the eventual capsizing.)
The Cabin Deck was built with portholes opening into the cabins that comprised the deck. Later called the 'tween deck after the cabins were removed, the portholes did not allow for a promenade for the passengers. As a result, most passengers typically congregated on the upper deck for the open view and to wave to people on the wharf. This concentration of passengers made the Eastland more top heavy than would normally be the case with a promenade deck one deck lower.
The ballast system was comprised of twelve separate tanks and was not quick to respond to the changes in weight distribution on the Eastland.Because the water in the ballast tanks was pumped out through the same manifold by which water was admitted to the tanks, the ballast system could not bring water into one side of the Eastland while simultaneously pumping water out of the other side.
The ballast system did not allow water to be pumped from the tanks on one side of the Eastland directly into the tanks on the other side.
The ballast tanks had no meters to gauge how much water was in each of the tanks. When filling the ballasts with water, the chief engineer had to estimate the amount of water in each tank based upon how much time had elapsed. Note, the ballast tanks did have vents which allowed for a dipstick type apparatus to be used to measure the amount of water, but this was a slow, manual process that did not allow the engineer to make quick decisions.
The ballast system was initially designed for the Eastland to allow it to quickly shift from a shallow draft while on the Black River into a deeper draft while out on the lake. But because the tanks frequently were only partially filled with water, this introduced a free surface effect that affected the stability of the ship. For example, when loading passengers from the wharf on the starboard side, the port ballast tanks were partially filled with water to help compensate for the concentration of weight on the starboard side.
In an effort to increase the speed of the Eastland, an Ellis & Eaves induced draft system was retrofitted into the Eastland. The additional weight of this equipment likely reduced metacentric height of the ship, making the Eastland less stable than it was previously.
To produce a cooler, dryer air flow into the interior of the Eastland, a McCreery air conditioning system was retrofitted into the ship. As with the induced draft system, the addition of the weight of the air conditioning equipment likely reduced the metacentric height, making the Eastland less stable than it was previously.
For the 1915 season, several dozen tons of concrete were added to the 'tween deck and the main deck floors. This likely reduced the metacentric height and made the Eastland less stable.
As a result of the sinking of the Titanic and specifically its huge loss of life due to the lack of lifeboats, the LaFollette's Seaman's Act was signed into law on March 4, 1915, requiring that lifeboats and rafts be made available based upon the number of passengers rather than the gross tonnage of the ship.
On July 2, 1915, three life boats and six life rafts (an additional 10-14 tons) were added to the top deck of the Eastland making it all the more top heavy and further reducing the metacentric height.
Please direct questions and comments to the Eastland Disaster Historical Society at firstname.lastname@example.org.
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