This lecture was presented at the 3D Digital Documentation Summit held July 10-12, 2012 at the Presidio, San Francisco, CA
Designing the LiDAR Mission for Industrial Heritage: Cooperation Across the Fields
Heritage managers and digital documentarians may observe the same subject, but observe it through a contrasting set of filters. The focus of this paper is to present an approach by which the capabilities of 3D digital documentation can be adapted to compliment the interests of cultural heritage management and the public it serves. The case study selected for this discussion is the Quincy Mining Company Historic District, a U.S. National Historic Mechanical Engineering Landmark, located within the boundaries of the Keweenaw National Historical Park in the Upper Peninsula of Michigan. Management and interpretation of the Quincy Mine site is the responsibility of the Quincy Mine Hoist Association (QMHA), the major stakeholder and owner of the site that is the focus of this study. Initial discussion with QMHA confirmed that little was known of the digital technologies available in the support of documentation and preservation of historical structures. QMHA also lacked exposure to Virtual or Augmented Realities (VR, AR) digital distribution including social media. The primary goal of this project is to assist the QMHA in guiding a reality-based survey (e.g. laser scanning, photogrammetry, etc.) to collect data which may be formatted into digital products to educate the public and enhance the enjoyment, respect, and appreciation of the Quincy Mine site. The project outlined in this paper will demonstrate the greater utility of integrating a cultural heritage management perspective with requirements of the survey to document, preserve, and manage heritage resources.
The subject used for the study is a prominent landmark locally known as the “Quincy No. 2 Rock House”. Built to receive skips of ore from over 9000 feet underground, the 147 foot tall shaft house is one of four industrial structures of its type remaining from the 1840-1968 copper mining era. The QMHA provides public access to the ground floor however safety issues prohibit tours and interpretation of the upper regions of the structure. This paper will document the process of conducting a terrestrial LiDAR-based mission designed to collect interior and exterior three-dimensional (3D) data of the rock house and process equipment, and will ACQUIRE photographs of selected machinery for photogrammetry-based 3D modeling. Data collected during the mission will be archived for documentation, preservation, and production of three-dimensional digital models.
As the use of LiDAR becomes more prevalent in heritage management, experts in a variety of technologies will be called upon to determine new methods of using limited resources to prioritize project design based on mission statements, to archive data for management and preservation, and to deliver data in formats compatible for creating virtual environments and 3D digital products.
By design, LiDAR surveys are generally not connected to the mission statements or the public concerns of heritage managers who may be responsible for operation and promotion of the site being surveyed. Typically, civil engineering firms are called upon to plan and conduct laser scanning missions for heritage documentation and preservation. While these firms posses the equipment and expertise, operators are usually trained as classical surveyors and lack skills required by the heritage sector. Heritage managers, on the other hand, may not be familiar with emerging technologies yet have the need to communicate the value and significance of their sites within the natural cultural setting and social context.
The process presented in this paper will serve as a model for engaging engineering and heritage professionals in designing comprehensive documentation and preservation experiences that positively influence appreciation of the Quincy Mining Company Historic District and similar heritage sites.
This morning as I was getting a cup of coffee, there was a guy standing next to me. He saw the name tag and he says, “Are you coming to the Summit” and I said “Yes, I am,” and he said, “What do you do?” I said, “I’m an industrial archeologist,” and he said, “Great, what is that?”
Industrial archeologists study industrial heritage, the physical remains of industry related artifacts, sites, processes and systems within their cultural and historic context. The case study for today’s presentation illustrates this by example.
Built in 1902, the Champion Number 4 is the earliest example of ore lifting and processing technology remaining from Michigan’s copper mining era. This structure is a mechanism built specifically to raise skips of copper ore from thousands of feet underground, unload that ore into bins, distribute the ore to crushers powered by steam engine and then transfer the resulting mineral to rail cars for shipment to a stamp mill located on Lake Superior at Frieda, fourteen miles distant. From 1902 to 1967, the Number 4 contributed to a local economy providing a workplace for husbands and fathers of families living in Painesdale, Michigan.
The International Committee for the Conservation of Industrial Heritage, TICCIH, is the world organization representing industrial heritage and is special advisor to ICOMOS on industrial heritage. In the charter presented to ICOMOS for ratification, TICCIH describes industrial heritage as the remains of an industrial culture which are the historical, technological, social, and architectural or of scientific value. By its mere existence, industrial heritage reminds us of previous ways of living or being in the world and illicit memories, discussion, and debate.
This morning we’re going to compare two results of missions conducted at two industrial sites that formed the basis of this presentation. To navigate the process, the project will be divided into three phases, results, and then conclusions.
Phase 1 was our experimental phase, where observations were made at a rescue type mission at the Cliff Mine Stamp Mill House and Washroom Archeological Site, where wooden remains were very well preserved from being buried under stamp sand since, we are not exactly sure, probably 1870. In Phase 2, the development, observations from the Cliff Mine were considered in conjunction with the needs of the Champion Mine Site to design a hybrid approach to data collection, which would also support future technologies for heritage interpretation. In this phase, the typical laser scanning mission was taken apart to understand how the equipment and software worked, what it can do, what it can’t do, and apply that knowledge to the needs of heritage. Then in Phase 3, 3D documentation, the challenge was to reassemble the components into an approach by which the capabilities of 3D digital documentation for preservation can be adapted to compliment the interests of cultural heritage management by scanning from the archeology. The results of the two missions will be compared and conclusions will be made.
As we proceed, the technology term refers to the professional firms and other interests which may include private investors, foundations, and governmental institutions. Heritage includes the professions who represent the mission to encourage the study, interpretation, and preservation of historically significant industrial sites, structures, artifacts, and technologies. The design represents the rules and controls technology and heritage professionals will follow when conducting the 3D documentation mission.
In the summer of 2011, an excavation was proceeding at the Cliff Mine Site near Eagle Harbor, Michigan. The site presented a Cornish influenced stamp mill that utilized non-industrial milling and ore washing technologies. The architecture presented evidence of extensive modification to the mineral washing process showing newer technology was integrated within existing constraints. The grooves eroded in the wood, maybe you can see them in the center of this slide, provide evidence the industrial archeologist can use to determine and interpret how slope and speed of water relates to the amount of copper being produced by this process.
The field school research team included students interested in the neat factor of LiDAR survey and discussion of the complex architecture lead to the desire to perform a LiDAR mission. The hope was to create a virtual model to study the interrelated parts of the ore washing technology and provide a quick test of future collaborative opportunities between the IA’s and survey student teams. The archeologists agreed and arranged for Clearwater Surveying to conduct a survey pro bono. The team was lead by a Michigan Tech graduate experienced with the operation of the Regal LMSZ 420 I long range 3D terrestrial laser scanner. The 420 is a battery powered long range time of flight scanner tethered to a laptop running dedicated software. It has an Nikon 300 camera collecting RGB data to color the point cloud. It soon became apparent scanner placement would be compromised due to its mechanical design. The two meter minimum distance to work required for the scanner to be positioned away from the edge of the excavation. Compounding the problem, limited vertical angle of tilt restricted the scanner’s ability to collect data in regions obstructed by architecture and depth of the excavation.
On a second setup, the laptop power was exhausted requiring the crew to remove the battery from their pick up, rig jumper cables with alligator clips and then complete the remaining four scans. When the data was presented to the team leader, not only was he unsure of what to do with it, he didn’t have software that could open the files.
Observations from the Cliff Mine mission demonstrate a lack of communication and understanding about the scope of the project. While some good data was collected, it was not delivered in usable format. Mechanical design of the scanner limited access to the archeology, power problems caused unexpected down time, and data was not delivered in a form the team leader could use.
In fairness to Clearwater Surveying, they volunteered their time. The Regal was the only scanner available and the project was outside their area of training and expertise. This said, a considerable amount of good data was collected and the process provided an alternative method of documentation when time and complexity was a concern.
The experience raises an important question for the archeologist considering LiDAR for documentation. If heritage and technology have difficulty communicating at this level, is other significant industrial and material culture being lost or failing to be documented. Considering the increased attention LiDAR is getting in the marketplace, it can be argued that within the industry there is a tendency for the technology to drive its use or in this case, drive the bus. An internet search returns demos and videos taking viewers on tours around and through point clouds and 3D models. Typically these firms are not connected to the mission statements or public interpretation concerns of heritage professionals. They may also lack awareness of how their data collection methods could impact new applications and distribution technologies being developed for the heritage sector. Complicating this, are the instances where the technology is oversold and fails to deliver the expected wow factor. Heritage managers, on the other hand, may be unfamiliar with LiDAR language yet have a need to communicate the value and significance of their sites within the natural cultural setting and social context. This situation leads us to Phase 2, development.
In contrast to the Cliff Mine project, the terrestrial LiDAR mission at the Champion Number 4 was designed to collect interior and exterior 3 dimensional data which we archived for documentation and preservation efforts, archeological study of machinery processes, artifacts, and other material culture for future production of media products used in heritage interpretation.
I put this picture in here to give you an idea of the complexity present in the building. The Champion Mine site is owned by Painesdale Mine & Shaft Incorporated. There’s no public access or interpretation however, PM&S arranges chaperoned access to the ground floor upon request. The structure prevents significant integrity as evidenced by endless belts still connecting line shafts to the crushers, and hand tools hang where the workman left them when the shaft house hoisted its last skiff of rock on September 11, 1967. Manual controls are evident throughout the structure suggesting the mining company made few improvements to modernize the facility throughout its period of operation.
Now in Phase 2 of the restoration project, a local engineering firm has been retained to complete a partial shaft house settlement study and while the focus of this study is on soil erosion at the top of the shaft cap, a manskip is left in position from 1967, causing concern for the roof and supporting structure. PM&S is also accepting bids to measure and restore windows. This is complicated of course by the heights and the poor quality of the floors in the building. Initial discussion with PM&S confirmed that while the organization lacked exposure to virtual or augmented realities, they considered digital presentation and marketing channels including social media necessary to their survival. PM&S also realizes funds are limited as current restoration and conservation efforts are consuming all monies received from membership donations and sales of cookbooks featuring ethnic recipes and collections of oral histories.
The primary goal of this project was to assist PM&S by guiding a LiDAR survey to collect data which may be used for preservation and be formatted into digital products to educate the public and enhance the enjoyment, respect, appreciation and conservation of the Champion Mine site. A walk through and study of photographs reveal safety concerns, including missing steps and the rotting floors. There was no electrical service to the building so visibility was poor and adequate power for flashlights and equipment would be necessary. Exacerbating these concerns was the overriding requirement that the scanning would need to be completed in one day.
The visual excavation identified types and location of machinery, material handling, production processes and other material important for interpretation. To determine extra costs and consideration, an unscientific but workable plan was devised. The technician would approach the assignment as a surveyor contracted to scan the building and he was allowed to choose his preferred scanning locations. The industrial archeologist then made suggestions after the data collector locations were chosen. Any variance was recorded as additional or modified scans.
Phase 3 goes on to present an overview of the process. Bruce Bowditch of Leica Geosystems volunteered his time and equipment as he is interested in developing vertical markets for scanning equipment used in heritage. He’s been with Leica for seven years as plant sales executive representative scanning products for the eastern US, including Geosystems product sales and training. Before joining Leica, Bruce was manager of 3D Laser Scanning & Pipeline Services Group at Holland Engineering Inc. The industrial heritage interest will be represented by Painesdale Mine & Shafting Inc. My position is that of an industrial archeologist responsible for designing the LiDAR mission and assisting PM&S with their restoration and preservation effort.
The general concept is to determine preferred scanner locations and to capture archeological data such as the drop hammer and shive and cable as seen in this part of the photo. We didn’t understand how this worked until we actually looked at this piece. In this part of the crusher floor the dark circles indicate scanner placement to record the two forty ton crushers and tools left against the wall. Another detail was revealed on the right side of the picture. The profile of ore remaining in the bin near an area where the walls. For the exteriors, scanner positions were of course selected to capture the architecture and recesses and inside corners, such as seen in the center of this picture. Scanning was accomplished by a Leica HDS7000. This ultra high speed phase based laser scanner is capable of collecting more than a million points per second but did not have the optional camera kit at that time which applies the RGB values of the photo to the actual points. The lack of color capability wasn’t an issue as the interior would have required supplemental lighting and this was not an option. Operating at eye level, it rotates 360 degrees horizontal. The vertical field of view is 320 degrees collecting a dome of points overhead.
This radial pattern has two important properties; first, point cloud is most dense near the scanner and second, lower resolution data is recommended at short distances. This knowledge can be used in a mission that specifies significant objects to be collected such as this improvised rock breaking hammer. These objects will receive an optimized scan based on best resolution and quality for the scan distance to target. In some instances, the level of detail is such that the scan can appear as a black and white historic photo as seen here on the lower left.
For media presentation, unified point clouds processed in Leica Cyclone can be exported to Cloudworks for animation within 3DS max design. And the max environment point cloud models can also exist and interact with other computer generated imagery such as vegetation and historic landscapes. Throughout the day, a tally was kept of additional and modified scanning positions. The results were compared to provide a comparison of the two scanning placement theories. At the bottom, you’ll notice that Bruce added scans. It was difficult to keep our interest separated but after adding positions and working out the cooperative procedure, the mission moved more quickly. At one point we were on the mezzanine and we both noticed the ore cart tipping feature on the skip road at the same time.
The Cliff Mine Stamp Mill was an open air excavation where the three crew members logged six scans in six hours and twenty minutes. In contrast, the two man team plagued by missing steps, rotting floors, multiple levels and ladders with loose rungs collected fifty interior scans in seven hours plus six exterior scans in under two hours the night before. In this case, the additional time spent to acquire data for heritage added approximately one hour to the interior scanning data.
Taking a look at what PM&S received at the end of the mission, they received a complete data set of exterior and interior framing that can be referenced and incorporated with existing hand and total station measurements. They have an inventory of windows and sizes to obtain bids on window replacement costs and inventory of rotting or missing floorboards and steps. Scanning for heritage complemented the structural survey by collecting reflectivity of subtle rust patterns of internal and external sheeting. Note that this was achieved without any supplemental lighting.
PM&S will have a unified point cloud to be viewed in a point cloud viewer and file conversion for modeling in 3DS max design. Use will also extend to provide cutaways of the shaft house to use for structural analysis. As you can see in this image, the beams above this area are deflecting. PM&S will also receive data in a form to be used for marketing and products for heritage interpretation. I brought along an example of what can be done with this. This is not a part of the discussion but if you’d like to know more about it, this is a 3D print model of one of these historic mine shaft houses.
Before concluding this presentation, I’d like to acknowledge Painesdale Mine and Shaft Inc., for allowing us to use the building for the study and thank Bruce Bowditch and Leica Geosystems for the time and commitment that was applied to this effort.
This snapshot of the Amick Number 2 shaft house meeting its demise is the laser scan of 1966. Without physical reminders of previous ways of living and being in the world, the ability to read the past is impoverished. While industrial structures present significant challenges for documentation and preservation, they offer significant opportunities for the industrial archeologist to recognize the working class life and acknowledge that something important went on in there.
Heritage managers and digital documentarians have the opportunity to see the same subject and cooperate to document it digitally in 3D. John Cage, the pioneer of the non standard use of musical instruments wrote, “I can’t understand why people are frightened of new ideas. I’m frightened of the old ones.”
Mark Dice has over 35 years experience in video media production and is pursuing a Master of Science in Industrial History and Archaeology degree at Michigan Technical University in Houghton, Michigan. He earned a BME in Music Education from Kansas State Teachers College Emporia, Kansas and launched a video production company in 1976. In 1982 Mark designed and built the first portable multi-camera production system for projecting live concerts and has participated in over 400 live events. Mark is researching ways data collected by laser scanning can be used to develop educational products for the enhancement of Heritage Tourism.
Timothy Goddard has fifteen years experience with geospatial technologies in archaeology and is writing a dissertation at Michigan Technological University’s PhD program in Industrial Heritage and Archaeology. Tim received his Bachelor’s degree in Anthropology from the University of Arizona, Master’s in Applied Anthropology (Historical Archaeology emphasis) and Certificate in Historic Preservation from the University of Maryland-College Park.. Tim is integrating GPS/GIS, total station, remote sensing, database design, virtual reality, field data collection, and network design into the work processes of archeological, biological, and environmental safety. Tim is a second generation archaeologist, merging spatial technology with archaeology methodology for heritage applications.