This is an original design for a ship that started with the idea, what if there was an immediate predecessor to the Constitution Class which also had a major refit? What would that look like?
I imagine the Endurance Class was smaller than the Constitution and of somewhat lesser technical sophistication. Nonetheless they underwent major rebuilds at around the same time as the Constitution class, though not to as massive an extent.
Length: 260m, beam: 121m, draft: 68m