Background:
Lester Franks was asked to provide an accurate 3D model of the Pyroclon (preheater) shafts at Cement Australia's Railton plant. This structure which is used in the production of cement had been in situ for considerable time and had experienced a build up of debris in unknown internal locations. Also, entry and exit points for maintenance were required to be determined. The pyroclon tower is a complicated and confined structure with limited hatches for internal access.

Methodology:
In order to access the internal structure, specially designed frames were constructed upon which to mount the laser scanner. Control points were accurately surveyed on the frames and brackets, and also selected internal structural locations. The pyroclon tower consists of seven levels, with small entry hatches available at most levels.
The mounted scanner was positioned within the tower and high resolution scans performed. The scans were calibrated against the surved control, joined and modelled to produce a 3D image.
The image was unwrapped so that the internal facing surfaces could be viewed as an outward facing model, for examination by the mechanical engineering team.
Design drawings of the original tower were not available, however drawings from similar structures were obtained so that comparisons to design could be conducted, and unscannable areas filled in.

Results:
A 3D model of approximately 20 mm accuracy was produced. Data was provided in multiple sectional views, together with DXF export and VRML file for client viewing within Internet Explorer. The innovatively obtained model was fit for purpose.