The origin of the T+

A tailor-made protection of paintings against shock and vibration during transport

"What should the packaging for a certain object or a class of objects look like, so that it provides maximum protection of the valuable cultural goods during transport?" This is the question of all questions before a tailor-made, object- or object class-specific packaging is designed by TURTLE. 

Along with the 9 other “Agents of Deterioration”, physical forces, such as caused by shock and vibration, represent one of the main threats for cultural goods during shipping. The result of consequent development and research regarding the transport of paintings with a lowlevel of structure-born noise is a painting holder with a novel vibration isolation and shock absorption concept. The TURTLE T+ development is based on the TURTLE corner blocks, which have been applied successfully in transporting paintings for many years. However, recent research shows that packing paintings with foams and elastomers does not produce the desired result in reducing vibrations. In addition to the correct dimensioning of the foam and elastomer mounts with respect to their shock absorption performance, creeping effects need to be considered. Since a wide range of paintings needs to be transported, the choice of the foam and elastomer is typically derived from the demands of the heaviest painting. As a consequence, lighter paintings experience an amplification of vibrations and hence degraded shock absorption. To achieve both vibration isolation and shock absorption, wire rope isolators are used in the TURTLE T+ instead of foam or elastomers for a wide range of paintings (from 0.7 kg to 42 kg). Furthermore, two configurations of TURTLE T+ are used as appropriate for the paintings. 

Vibration and shock testing are an indispensable step for the validation of newly developed parts and structures. Accordingly, in addition to the presentation of the T+ concept, this video presents the implementation and the results of the extensive vibration and shock testing campaign aimed to evaluate the effectivity of different types of crates and mountings including the T+. A total of five different types of crates with five different types of mountings have been tested. 15 canvas and panel painting dummies of various sizes and weights were used as test objects. The composition of the painting materials was known. According to recent research an equivalent stress concept based on modal velocities and geometric factors obtained from simplified finite element models is proposed. The measurement method includes real transport and transport simulation on a 1-D shaker. Additionally, the vibration response of the dummies to simultaneous excitation in 3 spatial directions on the 3-D shaker has been investigated. The nominal value of the excitation signal was derived from measurements during real transport. The vibration response of the dummies was acquired with lasers and strain gauges. This way, the values of mechanical stress occurring in the dummies could be determined.

However, due to the non-linear properties of the painting dummies, which are also present in originals, as well as the 3-D excitation, effects occurred that needed to be captured simultaneously on the entire surface with 2 high-speed cameras. The conclusion is that with the use of the T+ there are no high frequencies at the canvas, it is limited to 18 Hz. This is exactly how the T+ is calculated.

We managed to decrease excitation of the canvas above 18Hz to nil AND additionally a 50% reduction of the amplitude and frequency range.

We would like to thank  TU Berlin , especially the Coordinating Office for Women’s Advancement and Gender Equality, for their financial contribution to this project from the Joint Programmes for Female Scientists. We are also very grateful to Martin Engelke, expert on efficient vibration and environmental testing at  IMV Europe . And Ralf Lichtenberger, CEO of  LIMESS Measuring Technology , for supporting us with their expertise, time and equipment for this project. We also thank Christian Dindorf, Head of Bosch Center of Competence for Vibration at  Bosch , Schwieberdingen, and his team for their hospitality.

We are very happy to have found the way to offer this exceptional tailor-made protection for paintings. For more information please contact info@turtlebox.com.