Alternative timber to natural forest teak for shipbuilding

Lead Institute HF Institute of Wood Research

Investigation of alternative timber to natural teak with regard to their applicability in shipbuilding

In shipbuilding, teak (Tectona grandis, family LAMIACEAE) is traditionally used for the production of high-quality wood decks. As a result of the over-exploitation in its area of natural distribution, the availability of teak has decreased considerably. Furthermore, the importation of teak from Myanmar is currently prohibited due to EU sanctions.

Background and Objective

As a result of the overexploitation of teak in its natural distribution area Indochina (India, Sri Lanka, Myanmar, Thailand, Laos, Vietnam and Cambodia), the availability of natural resources has decreased considerably. Only in Myanmar (Burma) major resources are currently available, however, they are no longer permitted to be imported since the implementation of EU sanctions in June 2021. Based on this current (market) situation, the BMEL instructed the Thünen Institute to evaluate alternative timbers. Recherches have shown that tropical timber, e.g. Afzelia, Iroko and Itaubá, have comparable physical-mechanical properties as well as a high natural durability which correspond to the requirements for high-quality deckings. Compared to natural forest teak, no or only limited long-term experience in the utilisation as ship decking with high loads (working deck) are available for the selected timber. In this context, the properties of the alternative timber are being tested on an experimental facility (upper deck of the marine sailing ship Gorch Fock).

Target Group

Shipbuilding (Wood industry) and science (property testing of alternative timber)

Approach

For a comparative testing of the suitability of the alternative timbers, in particular as a high-quality deck on the sailing ship Gorch Fock, the following characteristics (properties) are tested in the laboratory and in practical use (test field on the upper deck of the Gorch Fock):

Moisture absorption and release (incl. speed) under changing climatic conditions
Dimensional stability (deformation behaviour during moisture changes depending on the anatomical directions)
Surface treatment and quality (cracking, leaching of wood components, UV stability and absorption of treatment agents).
Abrasion resistance and slip behaviour
Machinability for repairs

Accompanying to the monitoring of the alternative timbers on the test field (Achterback) of the Gorch Fock, artificial weathering tests and mechanical tests (impact bending strength) are carried out at the Thünen Institute of Wood Research in order to obtain comparative values of the wood properrties compared to natural forest teak.

Our Research Questions

Testing of the suitability of alternative timber (Afzelia, Iroko and Itaubá) under real operating conditions in shipbuilding (especially for a working deck)