HH ships in FT?

HH ships have inpenitrable wedges above and below the ship, connected on
each side by sidewalls. Now, the sheilds can be used to represent
sidewalls,
but I have some questions relating to if the systems ideas I`m going to
try
and explain would be beter or worse than normal FT systems (hope that
makes
sense).

Wedge/main drive & sheilds/sidewalls
The use of wedges alows you to roll them to interpose them between your
ship
and the enemy ship, thereby interdicting direct fire against you.
Against
this, you have to include the fact that you cannot sheild the front or
aft
of the ship. Also, because of the separate sides of the sheilds, as
forced
by the drive system, you have to include 2x sheilds (1x per side), for a
level one sheild protection. Would the fact that you have to pay twice
the
mass/cost of a normal sheild outwheigh the fact you would only lose one
sides sheilds at once, not all sheilds on a single threshold check (for
a
single screen level). Now, we have to weigh the cost of the drive
capable of
stopping any direct fire weapon (at the same time preventing your direct
fire weapons), against the cost of having to provide twice the sheilds
for
the same level of protection. My gut feeling is that you would be at a
slight disadvantage (cost/mass wize, tactically etc.), as opposed to a
normal ship, and that to over come this disadvantage, that every 5% mass
for
drive gives you 1.5 thrust (opposed to 1) for twice the cost of normal.
I
would say that sheilds/sidewalls have no effect againt missiles, and a
rolled to interpose wedge stops 50% of missiles (rounded down. i.e.-you
assign PDS against the salvo incoming, roll to see how many hit, roll to
see
how many PDS stops, the half the remaining missile are stopped by the
wedge,
rounded up (yes, a wedge could stop any remaining missiles from getting
through)).

This is just a rough idea at the moment, awating insparation for any
source
(i.e. HELP, this seems to be confusing me at the moment. I may work it
out
in a couple of days, but any help is apreciatted).

BIF
"Yorkshire born, yorkshire bred,
strong in arms, thick in head"