I have a book, US Cruisers, which (I guess) extensively discusses
development of ships of this class. It uses a term throughout that I
cannot find a reference for.

        The term is : STS     Does anyone recognise this abbreviation ?

 It refers to armor on upperworks mostly, although there is reference
to STS being installed on barbettes. Amount of armor is usually listed
in pounds. As in 25 lb STS installed around the "X" area...

I guess it is "steel", but what is this acronym ? Super Tough Stuff ?
Special Tungsten Steel ? Simply Tin Slag ?

While I'm here, can anyone define "abaft" for me ? I can't figure out
if that's behind, beside, or just "over there" !

        Many TIAs,

Additionally the cost of building it now would be too great (at $5,000/lb
to LEO....).  Also, IIRC, we have signed treaties stating we will not
base weapons in space (nukes that is...).

 Will

As an aside, it may have made sense at the time the DSBF was conceived,
but it is very hard to imagine that one would want to used large *manned*
vessels as launching platforms with current or future technology.

Remember, you don't *have* to do a complete sky search.  It suffices to
track each ship continuously, starting when it leaves port.  With passive
tracking, this can be done without alerting the ship.

As a practical note, also, nuclear-pulse engines are extremely expensive
to run.  (The Orion people assumed that fission-free bombs would become
available in the 1960s, but they didn't.)

The instruments on the Solar Max satellite -- which wasn't even designed
for gamma-ray astronomy! -- detected the USSR's Topaz experimental
satellite reactors quite well at quite substantial distances.  In fact,
the Topaz tests interfered quite noticeably with Solar Max's observations
of the Sun.

These particular problems can be circumvented somewhat by operating the
ion drive only intermittently, and by trying to point the emissions in
harmless directions.

Actually, I think the argument is fundamentally flawed, simultaneously in
opposite directions. :-)  First, I don't think even large space-based
radars are going to be able to fight the inverse-fourth-power law well
enough to be useful.  However, second, the most important point of
tracking DSBF ships is not to be able to find and destroy them during a
protracted war, but to be able to track them during peacetime, so that
attack forces can be positioned quietly and secretly to destroy them at
the very start of the war.  It's not necessary that such attack forces
be large vessels or that they trail the DSBF ships around, because the
bad guys don't need to be able to destroy the DSBF ships on a moment's
notice -- it suffices to be able to destroy them at a pre-planned time.

"Gosh, what a shame, all your DSBF ships were destroyed simultaneously
by meteorite impacts.  What an amazing coincidence that this happened
just as we invaded West Germany.  Of course, we had nothing to do with
it, and there's no cause to get hasty with your other nukes.  You'll
notice that *we* haven't used any nuclear weapons."

In any case, this is all a bit silly.  The same effect as DSBF can be had,
at vastly lower cost, with well-hidden missile bases on the Moon.  The
Moon is too large to search effectively, it provides ample background
clutter to hide low-powered bases, and lunar bases can be hardened against
attack much more easily.

(Of course, it's still a very expensive project that violates assorted
treaties and is impossible to justify since peace has broken out.)