Gules, on a pale Argent a railway spike Proper surmounted by a fleur-de-lis of the first.
On a wreath of the colors Argent and Gules, a winged wheel Argent.
Scarlet and white are the colors used for the Corps of Engineers. The railway spike represents the original organization as a railway maintenance-of-way battalion, and with the fleur-de-lis, alludes to service of the Battalion in France.
The winged wheel is taken from the World War I insignia of the Transportation Corps.
The coat of arms was originally approved for the 46th Engineer Regiment on 28 February 1942. It was redesignated for the 46th Engineer Construction Battalion on 13 November 1944. On 23 November 1953, the coat of arms was redesignated for the 46th Engineer Battalion.