Actually with a well placed nuclear warhead placed directly under the ship, it could be thrown out of the canal and into the nearby desert clearing the canal route /s
Those were what, 300kiloton’s ish? So if we go to 1+ megaton we’d be good. Seems reasonable if we go up to 3-4 megatons, maybe we’d even end up with a big enough crater one of these ships could pull a three point turn next time?
A better way would be to explode one medium sized nuke under the ship, wait a few seconds then explode another and then start exploding nukes behind it until it's going fast enough.
Project Orion did contemplate a 400m diameter ship weighing 8 million tons....
>Proposed uses for nuclear explosives under Project Plowshare included widening the Panama Canal, constructing a new sea-level waterway through Nicaragua nicknamed the Pan-Atomic Canal, cutting paths through mountainous areas for highways, and connecting inland river systems.