Seapower - October 2008

The Early Days of
Open Architecture

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 Horn.

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.