113 Years Later and We’re Still Talking About Watertight Compartments

Earlier this week, a Portuguese-flagged cargo container ship collided with an American-flagged tanker just off the Humber estuary in Yorkshire, England. The American-flagged ship, the Stena Immaculate, carries aviation fuel for the US Air Force. The Solong, the Portuguese-flagged tanker, carries alcohol, which is far better than the toxic chemicals initially feared.

We still know very little about the circumstances of the collision other than the Solong, travelling at 16 knots, slammed into the port side of the Stena Immaculate, which was anchored offshore.

I decided to write a little post because I enjoyed this graphic from the BBC, which details why the Stena Immaculate has not yet sunk—and at the time of my writing is not believed to be in danger of—despite the large hold amidships.

The graphic uses a simple line illustration of a bulk carrier in both 3/4 and a frontal view. The first shows how vessels like the Stena Immaculate separate their cargo into distinct holds, often watertight, so that, should a collision occur, the damage will not flood the entire ship or affect the load of the cargo. For the latter, sloshing liquids, as one example, can alter the centre of gravity and negatively impact ship stability.

The second line drawing illustrates the value of a double-hulled vessel wherein the outer hull shields the inner hull from puncture and prevents massive flooding of interior spaces.

Of course on 11 March, we are a little over a month away from the anniversary of the sinking of RMS Titanic. (In)famously in that case the critical issue was the same idea of watertight compartments. She had enough of them, but crucially they did not rise to the top of the ship as they would have necessarily impacted the luxury of first and second class accommodations. Titanic also did not have a double hull—her bottom was, but this did not run up the ship’s sides to the level where the iceberg impacted the ship.

Overall, I really like this graphic. It needs no elaborate and detailed illustration. Nor does it need sophisticated animations. All it uses is simple line illustrations.

Credit for the piece goes to the BBC graphics department.

The Sinking of the Vasa

In 1628, Sweden launched one of its largest and most powerful warships not just in Sweden, but in all of Europe. She was to participate in the wars with Poland and Lithuania as Sweden sought to expand her growing empire. After two years of construction in Stockholm’s naval yard she set sail into a calm day with a light breeze.

After a strong gust pushed her hard to port, she righted herself and continued to set sail to a fortress to load 300 troops for the war. But only 20 minutes into her maiden voyage, a second gust of wind pushed her again hard to port so much so that water began to flood in via her open lower gunports. As the continued to rush in, she never righted herself and sank, not to be recovered for 300 years.

The recovery itself is a great story, but the question was why did she sink? This model in the large Vasa museum, built to host the recovered and preserved ship, shows just how dangerously she was designed. Take careful note of the faint blue waves signifying the waterline of the ship and how close they are to the lower gunports.

Note the waterline on the lower crossbeam of the barrel to which the model is connected
Note the waterline on the lower crossbeam of the barrel to which the model is connected

The short takeaway is that the ship was top-heavy and she needed to be both wider and deeper to support her displacement. I like the model here, but my one complaint with it is the waterline. Even when I was standing in front of it, I did not notice the waves at first. A little bit more emphasis or paint, perhaps to show the water beneath the ship, would really help to convey just how little of the ship was below the waterline.

Credit for the piece goes to the Vasa Museum design staff.

The Sinking of the Bounty

This time last year, the Northeast began to pick up what was left from Hurricane Sandy. There was a lot of rain, a lot of wind, flooding, and electrical outages. But not all the damage was ashore. In an excellent long-form narrative piece, the Tampa Bay Times covered the story of the Bounty, a functional replica of HMS Bounty from that famous story of a mutiny. This Bounty was used in the 1960s movie and had sailed ever since until it sank off Cape Hatteras, North Carolina.

A diagram of the Bounty
A diagram of the Bounty

The piece doesn’t makes use of some charts and graphics to explain positioning and familiarise the reader with terminology. It’s a fascinating though ultimately tragic story. And like so many of these long-form pieces, the credit list is extensive.

Credit for the piece goes to Michael Kruse, Don Morris, Maurice Rivenbark, Carolyn Edds, Caryn Baird, Barbara Moch, Mike D’Andrea, Bill Duryea, Alexis N. Sanchez, and Lee Glynn.