Business Logo for Structural Engineer

We are a structural engineering business specialising in the design of steel structures for industrial applications. We would like a logo that presents a professional aesthetic. The name of the business is PSM Engineering. It would be good to have a symbol or logo that compliments the name and font. This could be an image type or stylised version of PSM.

The logo will often be embroidered onto shirts above the chest pocket.

Preferable colours are blue and grey/silver

Note it is for industrial not commercial highrise. It would be preferable not to have a building as a logo.