Eucalyptus tereticornis, Eucalyptus blakelyi ssp. blakelyi. Family: Myrtaceae
Blue gum, red gum, red iron gum.
|Description and natural occurrence|
A medium to tall forest tree attaining 20 to 50 m in height and up to 2 m in stem diameter. The trunk is usually straight and clear for more than half its height. The major limbs are more steeply inclined than in other eucalypt species. The bark surface is smooth with white, grey and bluish patches where bark pieces have been shed. Rough dark grey to black dead bark is retained at the base of the stem.
This species has the most extensive latitudinal distribution of the Eucalyptus genus, extending from coastal southeastern Victoria to north west of Laura in North Queensland. It is also found in southern Papua New Guinea.
Colour. Heartwood ranges in colour from red to dark red. The sapwood is distinctly paler in colour.
Grain. Moderately coarse, uniform textured, usually interlocked.
Density. E. tereticornis 1010 kg/m3 and E. blakelyi ssp. blakelyi 1055 kg/m3 at 12% moisture content; approximately 1.0 m3 of seasoned sawn timber per tonne.
Strength groups. E. tereticornis S3 unseasoned; SD4 seasoned. E. blakelyi ssp. blakelyi (S3) unseasoned; (SD4) seasoned.
Stress grades. F8, F11, F14, F17 (unseasoned), F11, F14, F17, F22 (seasoned), when visually stress graded in accordance with AS 2082-1979, Visually stress-graded hardwood for structural purposes.
Joint groups. J1 unseasoned; JD1 seasoned.
Shrinkage to 12% MC. 8.6% (tangential); 4.8% (radial).
Unit shrinkage. 0.34% (tangential); 0.25% (radial). These values apply to timber reconditioned after seasoning.
Durability above-ground. Class 1 - life expectancy over 40 years.
Durability in-ground. Class 1 - life expectancy over 25 years.
Lyctine susceptibility. E. tereticornis sapwood not susceptible to lyctid borer attack. E. blakelyi ssp. blakelyi susceptible to lyctid borer attack.
Termite resistance. Resistant.
Preservation. Sapwood readily accepts preservative impregnation but penetration of heartwood is negligible using currently available commercial processes.
Seasoning. Can be satisfactorily dried using conventional air and kiln seasoning methods.
Hardness. Very hard (rated 1 on a 6 class scale) in relation to indentation and ease of working with hand tools.
Machining. The interlocked grain often makes it difficult to dress cleanly on the radial surface.
Fixing. No difficulty has been experienced with the use of standard fittings and fastenings.
Gluing. As with most high-density species, machining and surface preparation should be done immediately before gluing.
Finishing. Will readily accept paint, stain and polish.
Engineering. As sawn and round timber in wharf and bridge construction, railway sleepers, cross arms, poles, piles (including wharf piles), mining timbers.
Construction. As sawn timber in general house framing, cladding, fascia and barge boards, internal and external flooring, linings, joinery, fencing, landscaping, retaining walls.
Decorative. Outdoor furniture, turnery, joinery.
Others. Structural plywood, boat building (keel and framing components, planking), coach, vehicle and carriage building.
Sapwood. Grey or cream-red, distinct from heartwood.
Heartwood. Ranging from light to dark red.
Texture. Uniform with interlocked grain.
Vessels. Small to medium in size, uniformly distributed. Seasonal growth zones often evident. Tyloses present. Vessels appear to adopt a pink yellow colour due to associated parenchyma and deposits when viewed by lens in cross section.
Parenchyma. Abundant and diffuse, containing deposits and some resin.
Rays. Fine, visible only with a lens.
Burning splinter test. A match size splinter burns slowly to charcoal with no ash.
Boland, DJ, Brooker, MIH, Chippendale, GM, Hall, N, Hyland, BPM, Johnston, RD, Kleinig, DA and Turner, JD 2006, 'Forest trees of Australia', 5th edn, CSIRO Publishing, Collingwood Australia.
Bootle, K 2005, 'Wood in Australia: types, properties and uses', 2nd edn, McGraw-Hill, Sydney.
Hopewell, G (ed.) 2006, 'Construction timbers in Queensland: properties and specifications for satisfactory performance of construction timbers in Queensland, Class 1 and Class 10 buildings', books 1 and 2, Department of Primary Industries and Fisheries, Brisbane.
Ilic, J 1991, 'CSIRO atlas of hardwoods', Crawford House Press, Bathurst, Australia.
Standards Australia, 2000, 'AS 2082-2000: Timber - hardwood - visually stress-graded for structural purposes', Standards Australia.
Forest red gum
Last updated 04 August 2010