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.
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.