Improved Method for Performing Surface Profile Assessments on US Navy Ships

Methods currently utilized for surface profile measurements, including replica tape and digital profilers, are both slow and labor intensive and provide only a single measure of the surface profile (the average maximum peak height).    For blasted steel surfaces, additional surface profile parameters such as the frequency of peaks per unit area, the highest peak in a given area, and the average roughness would provide additional information important to the proper adherence of both protective and nonskid coatings. 

In addition to surface profile, the topography (roughness) of newly applied and in-service nonskid cannot be characterized effectively in the field using current surface profile techniques.  Most nonskids have higher average maximum peak heights than the maximum range of commercially available replica tape.  Additionally, parameters including the density of ridges, the orientation of ridges, the extent of aggregate in troughs, and the slumping of ridges important to projected nonskid's performance are not obtained using  standard methods.

The Naval Research Laboratory has been exploring the use of non-contact laser based methods for measuring surface profiles of both blasted steel and nonskid surfaces.  The methods have been assessed for their ability to provide rapid (< 1 minute) high resolution (2 inch by 2 inch) and lower resolution (12 inch by 12 inch) scans of surface topology.  Further, an evaluation of these methods to characterize the topography of nonskid has been initiated.  Recent laboratory and shipboard studies have been completed using an NRL Surface Profile Tool based on laser technology.  These studies focused on the characterization of a variety of applied nonskid products on ship, as well as on laboratory analysis of blasted steel panels with different surface profiles.