Red Dust HoldingsLogo Design Contest

We are trying to mature our brand, to do this we need to develop a professional logo that is strong and bold but adaptable. To possibly include some form of an icon so we can use parts of the icon in different forms throughout our documents and website– similar to how Greenfield Technical Services has done this. Must include the letters RDH and also the words Red Dust Holdings.

Red Black Grey

Current logo attached, would like to 'mature' this but not re brand if possible. Digger can either stay or go.
Red digger logo attached is the best we've been presented with so far as a possibility of a new logo.