„Gules, a lowered anchor Argent between two escutcheons Argent; right an errected key gules with averted bit, left a crowned and armed azure lion rampant gules.“ The arms were granted in 1938 and show the symbols of the the patron saint of Electorate of Cologne (key) and Duchy of Berg (lion). The anchor symbolises the locatiion by the Rhine river.
This image is taken from www.ngw.nl – Heraldry of the World –  an international civic heraldry site by Ralf Hartemink. ngw.nl/heraldrywiki/index.php?title=Rodenkirchen (Köln)

Stadler, Klemens; Deutsche Wappen - Bundesrepublik Deutschland. Angelsachsen Verlag, 1972, Band 7 S. 84.
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