“What would adding fenders or deflectors do”
fenders or deflectors are made of concrete and steel pilings and are built strong enough to deflect a ship from crashing into what the “fender” is designed to protect.
The concrete support structure for the bridge appears to be in good condition, except where the steel anchors on top that hold the roadway was ripped off. They may be able to re-use those for the rebuilt bridge section. (depending of course on damage)
It appears the entire pier above water on the south side of the bridge collapsed. The condition of the concrete structure below the waterline is unknown, but based on a direct hit likely has damage. From what I have read the water is about 50’-55’ there. The further an impact is from the anchorage point the greater the moment of inertia, that is the force acting on the structure. A 116,000 ton cargo ship hitting the top of a structure 50+’tall is not something a fender or bumper is going to mitigate. You have to design from the get go for that kind of force, you don’t just strap some protection to the bridge pilings. Plus the ship had slowed down before it hit the bridge, so even if the pier survived it’s still very questionable it would have survived a faster collision.
The whole answer to this issue was to have tugs escort these ships out beyond the bridge to the open channel. Clearly that wasn’t the protocol and now the consequences are being felt.