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                                                                    EXHIBIT 21.1
 
                    SUBSIDIARIES OF POWELL INDUSTRIES, INC.
 
<TABLE>
<CAPTION>
        NAME OF DOMESTIC SUBSIDIARY                        STATE OF INCORPORATION
        ---------------------------                        ----------------------
<S>                                             <C>
Powell Electrical Manufacturing Co.             Delaware
Powell-Process Systems, Inc. (Inactive)         Utah
Powell-ESCO Company                             Texas
Unibus, Inc.                                    Ohio
U.S. Turbine Corp. (Inactive)                   Nevada
Transdyn Controls, Inc.                         California
</TABLE>
 
<TABLE>
<CAPTION>
         NAME OF FOREIGN SUBSIDIARY                       COUNTRY OF INCORPORATION
         --------------------------                       ------------------------
<S>                                             <C>
Powell Foreign Sales Corporation                Barbados, West Indies
</TABLE>
