From VTA and SIA to “Self-Referencing" for assessing and evaluating breakage safety of defective tree-stems.


Frank Rinn developed resistance drilling in the 1980s, invented and owns corresponding patents and trademarks (RESISTOGRAPH®) in more than 30 countries.

In the 1990s, Frank invented sonic tree-tomography and developed ARBOTOM®, patented internationally in 1999, for tree-stem and root-plate assessments.

In the 2000s, Frank explained on various conferences and in countless many workshops around the world, why the specific Visual Tree Assessment (“VTA”) thresholds (t/R>1/3! & H/D<50!) are not principally wrong but similarly inappropriate for evaluating the breakage safety of the typical mature urban and veteran tree as the “SIA” (Static Integrated Assessment) stability calculations are fundamentally wrong.


Based on bio-mechanical science, published by the few independent researchers in this field that are not led by economic interests (Niklas, Spatz, Telewski, Fratzl, Evans, …) Frank then developed a new method for evaluating the breakage safety of defective stem cross-sections of mature and veteran trees (by “Self-Referencing”) – and tested it successfully at thousands of trees in various countries.

The results fundamentally contradict established methods and call into question much of what is practiced in tree-risk-assessment and -management since 25 years (following professorial advices): the practical application of the VTA-thresholds and SIA calculations for assessing the breaking safety of the corresponding trees leads to an unnecessary and irretrievable loss of (urban) green, mature and veteran trees, biodiversity and valuable habitats because trees are pushed into a deadly as costly downward spiral by too much pruning and cabling. This is also a waste of (public and private) financial resources - and for this reason alone, public authorities in particular should have an interest in putting an end to this misguided kind of tree-risk management.


Karl J. Niklas (Cornell University, NY/USA), since long a world leading bio-mechanical scientist, clearly confirmed that the SIA stability calculations are fundamentally wrong as the VTA tree safety thresholds are inappropriate/inapplicable and described Frank’s “Self-Referencing” concept as “without doubt the most elegant method” he has ever seen for determining the breakage safety of defective trunks, far above other concepts and “totally defensible in court”.


Because the "leading" professional/scientific journals and many tree-care conferences on the one hand still present VTA/SIA and corresponding product marketing under the cover of alleged science, and, on the other hand reject criticism of these methods, we have set up our own publication platform, where you can read (and re-read) our corresponding articles as online-e-books.


Since the beginning of our company in 1988, our own research as well as our developments of technologies (resistance drilling, sonic tomography, tree-ring analysis, ...) and methods (timber inspection concepts, tree-ring cross-dating, tree-safety-self-referencing, ...) have not been financed by universities or taxpayers money, but from our own funds. We generate our income mainly in our own tree- and timber inspections as well as by tree-ring analysis-tools for dendro-chronology. Furthermore and in contrary to competitors, our diagnostic devices and methods are not promoted by only allegedly independent tax-paid professors from public Universities under the curtain of science. Therefore, we cannot give away our know-how for free but have to charge a fair and reasonable compensation for reading our online e-books.

But, workshop attendees, members of professional & environmental organizations, students and customers (having bought our diagnostic devices) get significant discounts (up to 100%). If you have a group of, for example, 15 arborists, you can book a real/live workshop at the tree or an online-seminar and then all attendees will get free access to the corresponding online-e-books. The same applies to Universities and other educational institutions, professional and environmental organizations - they all can obtain discounted bulk-licenses for members, staff and students. Just contact us in case you are interested. 


The issue "ArboSpectrum 2021/01" explains why VTA-thresholds and SIA-calculations are fundamentally wrong and similarly inappropriate for the breakage safety evaluation of the typical (and mostly mature urban) trees to be inspected in terms of safety. And, it describes how to do this job better by using “Self-Referencing”. The second issue "ArboSpectrum 2021/02" describes the bio-mechanical and mathematical basics of “Self-Referencing” and how to practically apply this method at the tree.


More documents are planned, some are in preparation, describing other aspects of technical examination of trees, tree-rings and timber structures as well as on efficient documentation in expert reports, crown-cabling, uprooting-safety, safety of multi-stem and leaning trees. If you have ideas for other topics we should publish, let us know. And, if you have interesting and valuable contents to share, submit a draft - we will check if this could be published in a future issue of ArboSpectrum.




Why did it take so long?

It took a few years longer than originally planned to publish these documents because we had to spend a large part of our time and financial resources for protecting our major inventions and patents (resistance drilling and sonic tomography) against plagiarism and, since 2011, for defending our “intellectual properties” against endless court proceedings. One of our main competitors had applied to courts (in Germany and USA) to cancel our trademark RESISTOGRAPH® (for more details, see: www.resistograph.com). Fortunately, after nearly 10 years of litigation, all courts recognized that the thousands of pages of claims and complaints against our RESISTOGRAPH trademark had no merit and no legal substance. And so, all trademark cancellation requests were dismissed by the judges as wrong and unfounded. But unfortunately, as the owner of the "intellectual property", we had to bear our own efforts and lawyer’s fees. The plaintiff did not achieve its goal of forcing us into bankruptcy (due to the huge costs incurred in defending our trademarks in court), but, a complex court case, driven by our corresponding competitor, concerning the misuse of our trademark RESISTOGRAPH® on a well-known Internet video platform is still ongoing. All this delayed our projects by more than 10 years.







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