The Early Days of
In the August article “BMD Boost,”
some statements brought back
memories of the steam turbine
practice while I was employed in
the steam turbine activity of the
Westinghouse Electric Corp.
The article noted the new combat
computer program called Advanced
Capability Build 12, which will be
open-architecture software. In the
1960s, the Westinghouse Steam
Turbine activity applied a computer
to control steam flow, power output,
speed, response to potentially damaging conditions and occurrence, as
well as synchronization.
This first design was an AEH,
Analogue Electro-Hydraulic, design. This was followed by the DEH
Mod I, Digital Electro-Hydraulic
computer control system. More
operating functions were included
in this computer. This was followed
by DEH Mod II, which had two
computers for greater reliability as
well as allowing for manual backup
in addition to incorporating additional capabilities.
Mod II incorporated open architecture both in regard to software
and off-the-shelf commercial components. Considerable effort was
needed to qualify the software for
use from modification and upgrading of the Mod I programs.
[The article states]: “The new
software ‘is more modularized,’ so
if they change parts of it, they will
have to test only the new piece,
instead of the ‘end-to-end test’
required for changes to the current
software,” he said.
The “he” is Rear Adm. Joseph
In the late 1980s and very early
1990s, Westinghouse developed
the MEH, Modular Electro-Hydraulic, computer control system. If there was a failure in the
memory card performing a specific
function, that particular card
would be removed, allowing manual control of that specific function. All of the other operating
functions would remain under
computer control as their memory
cards functions were unaffected by
the failed card.
Moreover, if a particular function were improved, only that
function would have to be qualified and a new memory card would
The DEH system also used two
computers and was compatible
with an overall plant computer,
being a “drop” on the data highway
of the plant computer.
George J. Silvestri Jr.