martesiawith some teredo, and at Colombo. The observations of the relative severity of
attack after 10^1 ⁄ 2 years of exposure were as shown in the following table:
Treatment Singapore Colombo
Coal–tar creosote to BS 144 Badly damaged Slightly to badly damaged
5% Celcure Very badly damaged Very badly to badly damaged
Coal–tar creosote with 1% of
copper napthenate Very badly to badly damaged Slightly to badly damaged
Coal–tar creosote with 5% of
copper napthenate Very badly damaged Very badly to badly damaged
It was concluded from the experiments that creosote gave marginally the best treatment
and that the addition of copper napthenate gave no advantage. Limnoria tripunctataare
tolerant to creosote but the species can be effectively controlled by the addition of
copper pentachlorophenate to the creosote. Although the range of preservatives available is
much reduced under EU Marketing Directives, creosote applied by qualified personnel
is still acceptable.
The Building Research Establishment (Farmer et al.(10.5)) lists the following timbers as
having heartwood resistant to borer attack. Those marked with an asterisk are believed to be
the best for marine work and their properties, durability, preservation and uses are described
in detail in the BRE publication.
African padauk (Pterocarpus soyauxii)
Afrormosia (Pericopsis elata)
Andaman padauk (Pterocarpus dalbergioides)
Basralocus (Angelique) (Dicorynia guianensis)
Belian (Eusideroxylyn zwageri)
Brush box (Tristania conferta)
Ekki (Lophira alata)
Greenheart (Ocotea rodiaei)
Iroko (Chlorophora excelsa)
Ironbark (Eucalyptus siderophloia)
Jarrah (Eucalyptus marginata)
Kapur (Dryobalanops spp)
Manbarklak (Eschweilera longipes)
Muninga (Pterocarpus angolensis)
Okan (Cyclicadiscus gabunensis)
Opepe (Nauclea diderrichii)
Pyinkado (Xylia xylocarpa)
Red louro (Ocotea rubra)
Southern blue gum (Eucalyptus globulus)
Teak (Tectona grandis)
Turpentine (Syncarpia laurifolia).
The sapwood of these timbers is liable to be attacked by borers, and if it is impossible
to ensure the removal of all sapwood the timber should be treated with creosote as a
precautionarymeasure. Greenheart fenders in Milford Haven were attacked in the sapwood by
teredo, causing about 10 mm of damage in five years.
The durability of piled foundations 485