Laser scanning was used to perform 3D scans of a column to ensure a conceptually identical reconstruction of it. Purpose and goal of the engineers was to replace a timeworn column of a major refinery in Hamburg (Germany).
Outdated technical drawings of the column
Only outdated technical drawings, originally created 35 years ago, were available that show the object in 2D and sectional views. As the past has shown, manufacturing drawings are usually not managed and updated in the context of plant and factory maintenance. Thus, all drawings were not reliable enough to use them for the project.
Furthermore, experience in the past has shown that around 90% of all installations do not fit properly if outdated drawings are the basis for rebuilding purposes of installations. This fact makes it necessary to use a real-world basis for planning decisions in order to professionally replace the column in a time-efficient manner. Due to precise digital representations and extremely accurate 3D data, laser scanning is an efficient and economic solution.
Conventional methods are superseded by 3D laser scanning
Poor visibility and obstruction of vision are a big problem for conventional methods. Furthermore, the column’s complexity and its extensions make measurements difficult to perform; and so is the interpretation of all measured points, which is extremely complicated and time-consuming. Furthermore, installation of the column will incur high costs if measurements are performed manually.
Particular attention may be drawn to the fact that laser scanning is a non-contact measurement method. Hence, it is an ideal basis for measurements and surveys of hard to reach areas, making it safer than other techniques. Conventional methods, i.e. tacheometry, disto and measuring tape, provide the engineer with a set of single points. The engineer will then create the CAD model on the basis of single points or aid constructions.
The challenge for designing engineers and planners lies in the correct interpretation and analysis of measuring points, which is difficult to accomplish if the engineer or planner has never visited the site or in the case of too few measurements.
In contrast to the method presented above, laser scanning will generate a complete and accurate representation of the entire column, enabling the planner to make use of the available information and laser scanner data at any time.
Laser scanning is the revolution for construction planning
Laserscanning Europe GmbH provided its expertise for the project and realized measurements, surveys and analysis tasks. It took only one day for the team of Laserscanning Europe to perform 22 scans of the plant, what resulted in a dimensionally accurate representation of the object in a very short time frame.
Modeling of the column according to drawings was done with Microstation and took only a few days. Another day was devoted to data synchronization, checking and creating the documentation. It goes without saying that it would have been an impossible task to accomplish in such a short period of time if conventional methods had been used.
