Boiler Explosion CSI

 

Captain James Haviland hauled himself out of the little yawl and onto the main deck of the wrecked sidewheeler. Bayou City was practically new, having been launched just a year before at Brownsville, Pennsylvania and purchased specifically for the Buffalo Bayou trade by John Sterrett. She was a big boat, at 275 tons and 165 feet in length, a Houston Navigation Company stable mate to that company’s Island City, capable of bringing loads of 250 or more bales of cotton to Galveston in a single trip during the season. She had been a grand boat, but not now. Now, she was a wreck, pushed up against the bank of the bayou to keep the channel clear for other boats. She’d blown up her boilers around one o’clock on the morning on September 28, 1860, while making the passage up Buffalo Bayou from Galveston. Now, two days later, it was the job of Captain Haviland and his fellow U.S. Steamboat Inspector, Israel Clark, to figure out what happened, even as efforts continued to find the bodies of victims and compile accurate lists of the dead and missing.

Fifty-year old Haviland was well-suited for the work. He was a steamboat master and pilot himself, having run steamboats between Galveston and landings on the Brazos for years. In 1842 Haviland’s boat, Lafiitte, was swamped and sunk while making the fifteen-mile passage in the open Gulf of Mexico between San Luis Pass, at the western end of Galveston Island, and the mouth of the Brazos River. This event helped shape his subsequent career, for several years later he turned his practical engineering skills to developing canal dredging equipment and took on a job as superintendent of the Galveston and Brazos Canal, an effort to create a sheltered, inland route between West Galveston Bay and the Brazos. The project took more than two years, opening in January 1854. The canal itself, the part cut through dry land, was short, less than five miles, but dredging and other improvements extended another thirty miles through an existing series of bays and lagoons to Galveston. The canal was only a very modest commercial success – it was found to be too narrow in some places, too shallow in others, and altogether too crooked – and it was found additionally that the steamboats’ sidewheels chewed away at the soft banks of the dredged channel, making repairs and upkeep an ongoing struggle. In spite of Haviland’s best efforts to keep costs to a minimum, within the years the Galveston and Brazos Navigation Company found itself $72,000 in debt. Regardless, the very existence of the canal must have been of great satisfaction to Haviland, for whom the loss of Lafitte more than a decade before would have remained a vivid memory.

Clambering over the wreck of Bayou City, Captain Haviland now faced a different challenge. Contemporary descriptions suggest that entire forward part of the boat much have been a splintered shambles. Picking through the wreckage, Haviland, and Clark their assistants discovered that the boilers had failed along their bottom surface, the blast wrecking the deck beneath them. The boilers themselves went the other way, crashing up through the main salon and cabins above, before falling back down into the hull of the boat. Following them down into the cloud of scalding steam and water came smashed cabin paneling, furniture, bedding, luggage, crockery, at least one passenger and the boat’s master. Passenger Thomas Westrop “had fallen in among the boilers, and died soon after being raised.” Captain James Forrest, who had been on the upper deck of the boat, was dropped down into the wreckage as well, but managed to extricate himself with only minor injuries. There were at least ten dead, total, including Isaiah Irvin, Speaker of the Georgia House of Representatives, and two African American men among the crew, who were property of Captain Forrest.

Now Haviland’s job was to figure out why.

Catastrophic boiler failures were dramatic not only for the resulting physical destruction to the boat, but also for the terrible, scalding burns they often caused. There was little real treatment for them, and if victims did not succumb quickly to shock, dehydration and infection usually finished them. Mark Twain’s younger brother, Henry Clemens, was fatally scalded when his boat, Pennsylvania, blew up her boilers on the Mississippi near Memphis in 1858. Twain recalled arriving at the public hall in Memphis where the injured had been taken:

The sight I saw when I entered that large hall was new and strange to me. Two long rows of prostrate forms — more than forty in all — and every face and head a shapeless wad of loose raw cotton. It was a grewsome [sic.] spectacle. I watched there six days and nights, and a very melancholy experience it was. There was one daily incident which was peculiarly depressing: this was the removal of the doomed to a chamber apart. It was done in order that the morale of the other patients might not be injuriously affected by seeing one of their number in the death-agony. The fated one was always carried out with as little stir as possible, and the stretcher was always hidden from sight by a wall of assistants; but no matter; everybody knew what that cluster of bent forms, with its muffled step and its slow movement, meant; and all eyes watched it wistfully, and a shudder went abreast of it like a wave.

Doctor Peyton, a principal physician, and rich in all the attributes that go to constitute high and flawless character, did all that educated judgment and trained skill could do for Henry; but, as the newspapers had said in the beginning, his hurts were past help. On the evening of the sixth day his wandering mind busied itself with matters far away, and his nerve-less fingers “picked at his coverlet.” His hour had struck; we bore him to the death-room, poor boy.

The explosive force and scalding steam from a boiler explosion were so great because, unlike many seagoing vessels, Western Rivers steamboats operated with “high pressure” machinery. The relatively small, lightweight engines used on the boats required a correspondingly high pressure of steam to produce a given amount of force, necessitating much higher steam pressures than on a seagoing steamship of comparable size, where the diameter of the main engine cylinder might be several feet across. Such a large engine might operate successfully under a single atmosphere, about 14.7 pounds per square inch, above the normal, ambient pressure of the atmosphere. By mid-century, though, the much smaller-diameter cylinders of the riverboats required steam pressures upwards of ten times that amount, with typical boiler operating pressures of 125 to 140 pounds per square inch above ambient.

This very high pressure is part of the reason for the high prevalence of scalding in cases of boiler failure. Under ordinary circumstances, fresh water boils at sea level at a temperature of 212° F. Adding more heat will not increase the temperature beyond that point; the water will just boil away faster. In a sealed container, though – say, a pressure cooker on the kitchen stove top or the boiler of a steamboat on Buffalo Bayou – the temperature of the water and the steam it produces will continue to increase, building up more pressure and raising the boiling point of the water still further. At a typical operating pressure of 120 pounds per square inch – 8.3 atmospheres – the boiling point of water climbs to around 340° F. This is known as superheated steam, water vapor at a temperature much higher than could be achieved in the open atmosphere. Under such conditions, a sudden, catastrophic loss of pressure containment – the collapse of a flue within the boiler, or a major breach of the boiler’s outer shell – would cause most of the hundreds of gallons of superheated water to flash almost instantly to superheated steam, rushing outward to envelop the boat and its crew and passengers. Though the temperature of the steam would drop rapidly as it expanded into the open atmosphere, only a few seconds’ exposure to the blast of superheated steam could easily cause a fatal scalding.

It was the aftermath of just such an event that Captain Haviland and his fellow U.S. Steamboat Inspector, Israel Clark, were tasked with investigating in the aftermath of the Bayou City explosion in the early autumn of 1860. Haviland and Clark determined that there had likely been a sufficient level of water in the boilers, and ruled that out as a likely cause of the disaster. The boilers themselves were nearly new, having been in service only a few months. But the inspectors soon focused on an accumulation of scale, a calcified layer of salt and other minerals, that had formed on the bottom part of the boiler, “as thick as the iron of which the boiler is composed.”[5] The accumulation of scale was always a problem on river steamboats, which ran tremendous volumes of dirty water from overside through the boilers, but it would have been particularly troublesome for the Buffalo Bayou boats, that spent half or more of their operating time in the salt water of Galveston Bay. Scale is a poor conductor or heat, and a thick layer of it prevents the heat from furnace gases being transmitted efficiently to the water inside the boiler. The metal shell of the boiler thus gets hotter — and softer — until it eventually collapses under the weight and pressure of the superheated water within.

Removing scale from the inside of a steamboat boiler was hard, dirty work, usually involving hammers and chisels to knock the concretions loose. Haviland and Clark, in interviewing the boat’s surviving crew, discovered that this vital work had not been done for several days before the disaster, allowing a dangerous quantity of scale to accumulate in the boiler. The inspectors revoked the licenses of Bayou City’s two surviving engineers, Numa M. Whitson and John Curly, for “ignorance or neglect of duty” in not keeping the boilers properly clear of scale, and allowing it “to accumulate on the boilers of that boat to such a degree as to cause the fatal explosion heretofore reported.”

Comments are closed.