Most of their worlds have a TL of 14, so they can design and build their own ships. Why they would bother with something as insignificant as a Kinunir is a mystery, as is why the Imperium donated a Kinunir in the first place.
Hans
Because it needs retconning to either the Imperium donating a real battle cruiser or the Kinunir redesigned as a HG2 70kt state of the art TL15 warship.
Otherwise the battle of the two suns and the donation to the Vegans is laughable at best...
As Mike points out, there's a bit of a bump in 1979 around what kind of ships the Imperium has and what size of ship is a battle cruiser or not.
Re-reading the introduction to
High Guard, my interpretation is that the book was designed to be a generic set of instructions for building any kind of ship (at almost any scale) players wanted to build. But nowhere doe the book suggest that every scale within
High Guard should be available in every
Traveller game. It is a set of rules to be used as the players wish. Moreover, the text does not suggest the the Traveller OTU has ships of a scale larger than those found in Book 2.
Here is the text:
Traveller assumes a remote centralized government (referred to in this volume as the Imperium) possessed of great industrial and technological might; but due to the sheer distances and travel times involved within its star-spanning realm, the lmperium is unable to be everywhere at once. As a result, the lmperium allows a large degree of autonomy to its subject worlds, calling only for some respect for its overall policies, and for a united front against outside pressures.
To monitor the space lanes, the lmperium maintains a Navy. Because these forces can never be everywhere at once, local provinces (subsectors) also maintain navies, as do individual worlds. This three tiered structure of Imperial, subsector, and planetary navies produces a flexible system for patrolling space, while putting the limited resources of the lmperium to best use.
High Guard deals with the navies of the Imperium, of subsectors, and of worlds.
Note that the text is explicit:
Traveller assumes the PCs will adventure in an area remote from some sort of centralized government. What that government is is not defined. The generic term used for the rule book is "The Imperium" for the purposes of the book. But it clearly is not
the Imperium of the OTU. (If this seems puzzling, re-read the text.)
The fact that
High Guard allowed 500,000 ton ships didn't mean that they had to exist in a
Traveller game, nor that they had to be part of the OTU. As Miller has said in a quote I posted elsewhere, GDW was only beginning to build out the OTU in 1979 -- two years after the release of the original boxed set.
I suspect that in 1979 -- when both
High Guard and
Adventure 1 The Kinunir came out -- Miller was still working with the assumption of a "Small Ship" universe of Books 1-3 for the adventure. His Battle Cruiser was, after all, only 1,200 tons. Either 1,200 tons is a big deal... or it isn't.
In Adventure 1 it was a big deal. In later supplements, as OTU took over, the
potential of ships in
High Guard became the default.
I can only work with the text of Adventure 1, High Guard, and Miller's quotes to come to this conclusion, but it seems to fit.
Because, as both Hans and Mike point out, there's a bump in exactly whether the Kinunir is a Battle Cruiser or not. Clearly it was a battle cruiser in Adventure 1. But as the ships got larger and larger in the OTU, it wasn't one at all.
