...and as the article says, "Furthermore, some of the world's main waterways such as the Suez Canal and Singapore Strait also restrict the maximum dimensions of a ship that can pass through them.", which explains why the list consists of large fleets of ships all almost exactly the same size.
Much like Panamax being the largest ship size which can traverse the Panama canal, there's a corresponding Suezmax[1]. Sort of like the old story of the Space Shuttle's SRB size being dictated by old Roman road design, it's interesting how modern design is influenced by historical limitations we might not consider.
The Shuttle SRB design still was dictated at least in part by the segments being transported by rail - each individual segment could be only as heavy, wide and long as the cobined stretch of railway from the factory would allow.
It influences other rockets as well - for example the Proton:
The long thin tanks you see mounted on the first stage are not drop tanks or additional boosters, its the tanks holding the first stage fuel, with the central core holding all the oxidzer.
Thats because the core stage is limitted in width by what you can ship to Bayokonur by rail, especialy IIRC one specific rail tunnel on the route. So they ship the core stage and the additional fuel tanks on separate rail cars and then bolt them in place on the cosmodrome.
In similar manner Falcon 9 is limitted to 3.9 m of width as that is the maximum you can ship over the US highway network without special care.
If you want to go bigger, you need special aircraft and barges, or build the thing in place like it is currently being done with the SpaceX Starhip.
One of the main roads near where I live is a Roman road. It's fascinating that the new buildings being built along it have their design constrained, in some way, by a decision made 2000 years ago.
