Introduction |
The Standard Malaysian Name for the timber of
Neobalanocarpus heimii (Dipterocarpaceae). Vernacular names applied
include penak (Peninsular Malaysia). The name chengal is so popular,
that many other species have been given vernacular names bearing the
name chengal. Neobalanocarpus is a monotypic genus. The sapwood is light
yellow and sharply defined from the heartwood, which is light
yellow-brown with a distinct green tinge, darkening on exposure to dark
purple-brown or rust-red. Also known as Chengal (Brunei); and Chan Ta
Khien, Chi-ngamat, Takian Chan and Takian Chantamaeo (Thailand). |
Botanical Name |
Balanocarpus heimii. Family: Dipterocarpaceae |
Natural Durability |
The timber is classified as naturally durable and is
normally very resistant to termite attack and fungal infestation. Under
graveyard test conditions, untreated specimens of size 50 mm x 50 mm x
600 mm lasted 9 years. Treated specimen of the same size and test
conditions lasted about 19 years. Untreated railway sleepers of size 238
mm x 125 mm x 1,950 mm laid under severe environmental conditions gave
an average service life of 19 years. |
Uses |
The timber is suitable for all forms of heavy
construction, railway sleepers, heavy duty furniture, laboratory
benches, bridges, marine construction, boat building, telegraphic and
power transmission posts and cross arms, piling, mallets, flooring
(heavy traffic), decking, vehicle bodies (framework and floor boards),
fender supports, cooling towers (structural members), staircase
(balusters, carriages, handrails, newels, risers, stringers, treads,
bullnoses, round ends and winders), columns (heavy duty), door and
window frames and sills, tool handles (impact), carving works and other
uses where strength and durability are required. |
Texture |
Texture is fine and even, with shallowly to deeply interlocked grain. |
Density |
The timber is a Heavy Hardwood with a density of 915-980 kg/m3 air dry. |
Shrinkage |
Shrinkage is fairly low, with radial shrinkage averaging 1.1% and tangential shrinkage averaging 2.6%. |
Defect |
Small pin-holes, caused by ambrosia beetles boring
into the living trees, are a common and characteristic defect of
chengal. These small holes are often numerous, but although unsightly,
they are only in exceptional cases sufficiently numerous to impair the
strength of the timber. These ambrosia beetles die when the timber is
seasoned and thus the damage is restricted almost entirely to that which
occurs in the green timber. Big trees of chengal are sometimes hollow
at the centre and badly attacked by large borers, and occasional trees
are seriously infected by a fungus (Fomes spp.), which initially gains
entry through broken branches or other wounds and eventually reduces the
timber to a dark pulpy condition. With the exception of pin holes, the
timber of chengal is free from knots and other defects characteristic of
sawn timber. |