In fact, it is one of those great ironies of history that the Eastland disaster was caused by the government’s reaction to the sinking of the Titanic – specifically, by the La Follette Seamen’s Act of 1915, named for the “Progressive” Republican from Wisconsin, Senator Robert La Follette, which among other things required additional lifeboats and rafts on all American passenger ships. The mandate of the La Follette Act extended even to Great Lakes steamers, even though they were built differently – their hulls had much shallower drafts – than trans-Atlantic liners, making them unstable and top-heavy when loaded with the extra lifeboats and rafts the Act required. The owners of the Eastland, in partial satisfaction of the provisions of the La Follette Act (which was set to come into force later in the year 1915), added a number of boats and rafts to the ship’s top deck, just three weeks before the Western Electric picnic. The addition of those lifeboats, which were never used – the ship had capsized and sunk too quickly for them to be any use – was a crucial cause of the disaster. Something caused the ship to list to one side; and before it even left its dock, the ship overturned, trapping many of the victims in the lower decks.To be precise, not all shallow-draft steamers are tender. There's something called the metacentric height that affects a boat's stability. A ship with a low metacentric height and partially filled ballast tanks can get you into trouble very quickly. Something like this befell Eastland well before she was fitted with the additional lifeboats.
Early in her career, Eastland had a very close call. On July 17, 1904 after leaving South Haven, Eastland was running at full speed with a load of 3,000 passengers. About 1.5 miles out into Lake Michigan, the ship, for no obvious reason, began listing to port by some 12 to 15 degrees. Her ballast tanks were partially full. The crew reduced speed, ordered the passengers off the upper decks and shifted water in the tanks to right the vessel. In some 10 minutes the ship straightened up, but immediately began to list more severely to starboard; some 20 to 25 degrees. With further filling of the tanks and shifting of the passengers, the list was corrected and the Eastland proceeded to Chicago. This was a very close call. Had the ship capsized, she would have continued over until she floated keel-up, with a huge loss of life.There's a book by transport historian George Hilton about the Eastland capsize that makes use of what naval architects have learned about tender boats. The list to starboard as a consequence of flooding to correct a list to port is an illustration of the difficulties that arise on a boat with a low metacentric height and partially-filled ballast tanks. I had some observations about the Eastland capsize two years ago, with links; here is the Eastland Disaster site.