Mad about Science: Big ships

By Brenden Bobby
Reader Columnist

Earlier this week, tragedy struck in Baltimore when the container ship the MV Dali collided with the supports of the Francis Scott Key Bridge, which brought the entire bridge down into the harbor. At the time of the writing of this article (March 26), there had been one confirmed death and six lives presumed to be lost.

Immediately, the internet was abuzz with chatter about how such a thing could possibly happen or how anyone could be so irresponsible as to crash a container ship into a bridge. The details are still unfolding, but it’s important to know that these ships are huge. The MV Dali is 299.92 meters long (almost 984 feet) and has a gross weight of about 95,000 tons. A Mack truck loaded to about 25 tons takes roughly 10.5 seconds to brake to a full stop at highway speeds and even more if conditions are wet.

The USS Gerald R. Ford. File photo.

As huge as it is, the MV Dali doesn’t even come close to being the largest ship on the ocean. One ship that’s almost 50% bigger than the MV Dali is even designed to carry people for leisure.

The Allure of the Seas is an Oasis-class cruise ship that came with a price tag of $1.2 billion. Owned and operated by Royal Caribbean International, this ship is 360 meters long (1,181 feet), 72 meters high (236 feet) and has a gross tonnage of more than 225,000 tons. 

This behemoth is designed to carry as many as 6,780 passengers at maximum capacity, as well as a crew of 2,200 people. The Allure of the Seas is basically Sandpoint at sea.

As you can imagine, this cruise ship isn’t designed to go very fast. Something that heavy isn’t capable of breakneck speeds; however, with three engines putting out 27,000 horsepower, this brute is fully capable of outpacing Usain Bolt with a top speed of about 26.5 miles per hour. (In case you’re curious, Usain Bolt topped out at 23.35 mph on dry land.)

It’s hard to put the hugeness of this vessel into perspective. The most infamous ocean liner that served a similar purpose was the RMS Titanic. Huge for its time, spanning 269 meters in length (882.5 feet) and with a gross tonnage of 46,329, this doomed vessel was a minnow sitting next to The Allure of the Seas. Despite being smaller even than the MV Dali — which crashed into the Francis Scott Key Bridge — the Titanic sported some serious power under the proverbial hood, with boilers feeding two steam engines with an output of 46,000 horsepower. Unfortunately for the Titanic, that level oomph likely exacerbated the dire effects of slamming into a giant block of ice.

The Allure of the Seas doesn’t have to worry about icebergs, as it primarily sails half-week trips to the Bahamas. However, hurricanes and intense wind on a structure that huge are very likely to be a concern.

The largest vessel we know of in U.S. military service is the USS Gerald R. Ford, a 333-meter-long (1,092.5-foot) aircraft carrier that cost more than 10 times as much as The Allure of the Seas — in excess of $13 billion. 

Powered by two A1B pressurized water nuclear reactors, this ship only needs to be refueled once every 25 years. It comes equipped with four surface-to-air missile launchers, three automated Phalanx CIWS automated weapon systems, four 25mm machine gun systems and four 50-caliber machine guns for good measure. 

If this doesn’t sound like a tremendous amount of firepower for a warship of such size, that’s because the USS Gerald R. Ford is a carrier and the entire span of its deck is for launching aircraft. The weapons onboard are essentially a last-ditch effort in case small-arms combatants somehow get close enough to nearly board the ship.

Fitting of a war vessel, this ship can easily outpace the cruise liners by topping out around 35 mph. And it’s tough. Before the ship was even brought into service, the Navy detonated large explosives in very close proximity to the ship as a part of its final shock trials. This ensures the ship will withstand direct fire and won’t join the Titanic in Davy Jones’ locker. These blasts aren’t like anything you’ve seen on the Fourth of July. For such trials, the Navy detonates a 40,000-pound explosive, which carries the equivalent force of a 3.9-magnitude earthquake.

The final ship we’ll look at was the largest ship ever built in human history. It was an older ship with a slew of names, but was originally built as the TT Seawise Giant from Yokosuka, Kanagawa, Japan. It spanned 458 meters (1,502.6 feet) and was capable of carrying 4.1 million barrels of oil. It had the greatest displacement of any ship in the world at 657,019 tons.

A ship this size was not built to go fast, and it capped out around 19 mph. 

When you consider something that was nearly the length of Travers, Centennial and Great Northern Parks combined moving at 19 miles per hour, that’s an engineering marvel if you’ve ever seen one.

The ship was in service from 1979 until 2010 when it was finally scrapped. During its service it was actually struck by bombs and lit on fire during the Iran-Iraq War in 1988. Now that one’s one tough boat.

Stay curious, 7B.