Field tests of different tropical wood species in sea water
M Westin, P Larsson Brelid
A number of tropical timbers have been tested according to EN 275 at Kristineberg Marine Research Station in Sweden since 1999. Most of these tests have started during the last 5-8 years.
Wood species included have been Lophira alata (Azobé/Ekki), Minquartia guianensis (Manwood/Acaria), Chlorocardium rodiei (Greenheart), Cyclodiscus gabonensis (Okan/Denya), Shorea spp. (Bankirai), Dicorynia guianensis (Basralocus/Angélique), Tectona grandis (Teak) and Handroanthus spp. (Ipé). Only one of the wood species included have shown to be highly resistant to marine borer attack, Manwood/Acaria, which is also the wood specie that performed best in a marine test in Portugal (Williams et al. 2007). The test group of Manwood/Acaria is still rated “sound” after 22 years in our test. The performance of the other species is surprisingly poor with e.g., average life (time to failure due to shipworm attack) of only 3.8 years for both Greenheart and Okan/Denya. This seems to be in line with speculations about increased borer activity on the Swedish West coast causing increased shipworm attack on harbour constructions of tropical wood, mainly Azobé. In our test Azobé got an overall rating of “Failure” after 8 years in test.