Shield
Per fess Argent and Gules in chief a spur gear, in base a shovel fesswise, handle to sinister, counterchanged.
Crest
On a wreath of the colors Argent and Gules, a fleur-de-lis and a double axe head per cross of the first charged with a wavy bar fesswise Azure.
Motto
AGENDO GNAVITER (By Doing Diligently).
Shield
In the scarlet and white of the Engineer Corps, the functions of the organization are aptly illustrated in the gear and shovel, both symbolizing the mechanical and hand tools necessary in the performance of their work.
Crest
The fleur-de-lis is used to symbolize France, and the double axe head is placed to represent the unit's action across her border. The wavy blue bar is used to symbolize the Rhineland. The two blades of the axe refer to the two campaign honors awarded the unit during World War II.
The coat of arms was originally approved for the 377th Engineer Battalion, Organized Reserve on 14 October 1942. It was redesignated for the 377th Engineer General Service Regiment on 15 September 1943. It was redesignated for the 577th Engineer Battalion (Construction) and amended by deletion of the Organized Reserve crest on 8 March 1955. The coat of arms was amended to add a crest on 15 February 1967.