Shipyard workers would sometimes refer to that hull as Gigantic, but only in a joking way.
And you need to read posts more carefully.
Even today, in such organizations as NASA, it is not unusual to give informal names to major assemblies rather than refer to them by numbers that can be many digits long and are vulnerable to transposition or other errors.
The “Gigantic†notation
in red would indicate that someone at Hingleys did just that.
The appearance of “Gigantic†in the LNWR correspondence would follow from the colloquial use of “Gigantic†by Hingleys, and is not independent proof of anything.
The very article you cite indicates, by the paucity of references to “Gigantic†among the voluminous H&W documents, that “Gigantic†was never an official name for that hull.
If you come down on Christmas morning an find that someone has taken a bite out of one of the cookies you left, that is hardly irrefutable proof of the existence of Santa Claus.
