That ship had a 10,000 TEU capacity and was actually hauling a little under 5,000 TEUs. An empty container weighs a little over 5,000lbs, and a full one can be up to 67,000lbs.
If you do the math, you find that it’s just an astronomical amount of momentum, and there’s no effective defense for a bridge that needs support in more than 30 or so feet of water.
Throwback to the scene in The Day After Tomorrow where the cargo ship comes to an almost instant halt after impacting a bus wreck under water. For some reason it managed to stand out as ridiculous even in that movie.
I just saw in a YouTube video yesterday that they actually built a full-size model of the ship (or at least the bow area) and the bit of town it hit. The director didn’t want to use CGI or miniatures.
He spent a full quarter of the movie’s budget on that one scene.
there’s no effective defense for a bridge that needs support in more than 30 or so feet of water
You put in sheet piling 50 meters upstream, and you fill the box with rocks. That's state of the art practice, nowadays, but that bridge was 50 years old.
In 1977 (and in 1972, when construction began), vessels of this size did not exist, and certainly were not allowed in the harbor[1]. But over time, they were given authorization, despite the fact that they could collapse the unprotected bridge like a load of toothpicks.
The real crime here is that there was no retrofit to protect the pylons. It was almost certainly considered and rejected due to cost.
The Oil Tankers of the 70s were the largest vessels ever built. Today the largest container vessels are starting to creep up to their size, but not weight.
The container vessel in question is tiny compared to e.g. the Seawise giant or Batillus Class.
If Baltimore had been anticipating VLCC traffic in the 70s, then presumably the bridge would have been built accordingly and this incident would not have led to a collapse.
According to the marine traffic track shown in the YouTube analysis above, the ship looks to have been heading through the channel, but then nosed in right under the bridge. Would have sailed right past upstream dolphins, and rammed the pylon from the inside anyway.
the modern practice is layers of defense; in addition to building a bridge that doesn't fail at a single point of failure, you also generally design what's around a bridge pier to stop or at least slow down the ship (by, say, running aground onto a bed of rocks around a pier)
"A notable example of dolphins used to protect a bridge is the Sunshine Skyway Bridge across the mouth of Tampa Bay. In 1980, the MV Summit Venture hit a pier on one of the bridge's two, two-lane spans causing a 1,200-foot (370 m) section of the bridge to fall into the water, resulting in 35 deaths. When a replacement span was designed, a top priority was to prevent ships from colliding with the new bridge..."
The MV Summit Venture was a 33,900 deadweight tonnage ship. MV Dali was a gross tonnage of 95,128. Nearly 3× as large. It's questionable whether dolphins would have totally prevented such a tragedy.
Yet similarly, expect dolphins to be brought up as a key component of resiliency for any designed replacement bridge.
Jeasus - seriously - if that was an inbound shipment then it would be worse - this appears to have been leaving - which would infer that the TEUs were more empty than full.
North America has lots of land and oil. Timber (Canada), plastics, and corn fertilised by nitrates that were made using fossil fuel energy. Corn probably doesn’t ship in containers but corn-fed beef and poultry do?
Some import products are crazy cheap because cross-planet shipping is basically free because it's the reverse end of a trip carrying valuable stuff. But they mainly applies to ships returning from low development level regions.
While the majority is bulk, the US does export a lot of industrial machinery. It's just not stuff you normally think about - like the large hvac systems on the roof of large buildings or the caterpillar earth moving equipment/parts to make roads.
Apparently, I was wrong - they are reporting it as a "fully loaded" -- but that does not mean the TEUs were full of goods and services... but thats what they are calling it. So I have no Idea.
Unless ImportYtei.com can get the bills of lading for that ship....
You put it ahead of the pylon so that even when the dolphin or bollard is destroyed, it redirects the ship to—at worst—a glancing blow with the pylon.
You don’t need to dissipate every joule of kinetic energy in the vessel. You just need to redirect it away from the pylon. That horizontal component can be done with bollards and dolphins sufficiently that even a relatively direct original angle should only damage the fenders. From what I see, there were zero such protections around this bridge.
Nothing can protect against a direct hit. But most hits aren’t direct, and those can be redirected without catastrophic pylon failure.
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If you do the math, you find that it’s just an astronomical amount of momentum, and there’s no effective defense for a bridge that needs support in more than 30 or so feet of water.