Forest red gum
Scientific name
Eucalyptus tereticornis, E. blakelyi ssp. blakelyi. Family: Myrtaceae
Other names
Blue gum; red gum; red iron gum
Description
- Medium to tall forest tree.
- Grows 20–50m high.
- Stem diameter up to 2m.
- Trunk is usually straight and clear for more than half its height.
- Major limbs are more steeply inclined than in other eucalypt species.
- Bark surface is smooth with white, grey and bluish patches from bark shedding.
- Rough, dead bark (dark grey to black) is retained at the base of the stem.
Occurrence
- The most extensive latitudinal distribution of the Eucalyptus genus.
- Extends from coastal south-eastern Victoria to northwest of Laura in North Queensland.
- Found in southern Papua New Guinea.
Appearance
Colour
- Heartwood ranges in colour from red to dark red.
- Sapwood is distinctly paler in colour.
Grain
- Moderately coarse, uniform textured, usually interlocked.
Uses
- Engineering: sawn and round timber used to construct wharves and bridges, railway sleepers, cross arms, poles, piles (including wharf piles), mining timbers.
- Construction: 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.
Properties
- Density: E. tereticornis is 1010kg/m3 and E. blakelyi ssp. blakelyi is 1055kg/m3 at 12% moisture content; about 1.0m3 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 according to AS 2082—2000: Timber—Hardwood—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 more than 40 years).
- Durability in-ground: Class 1 (life expectancy more than 25 years).
- Lyctine susceptibility: E. tereticornissapwood not susceptible to lyctid borer attack; E. blakelyi ssp. blakelyi is susceptible to lyctid borer attack.
- Termite resistance: resistant.
- Preservation: sapwood readily impregnates with preservative, unlike the heartwood, where penetration is negligible using available commercial processes.
- Seasoning: satisfactorily dries using conventional air and kiln seasoning.
- Hardness: very hard (rated 1 on a 6-class scale) to indent and work with hand tools.
- Machining: interlocked grain often makes it difficult to dress cleanly on the radial surface.
- Fixing: no difficulty using standard fittings and fastenings.
- Gluing: as with most high-density species, machine and prepare surface immediately before gluing.
- Finishing: readily accepts paint, stain and polish.
Identification features
General characteristics
- Sapwood: grey or cream red, distinct from heartwood.
- Heartwood: ranges from light to dark red.
- Texture: uniform with interlocked grain.
Wood structure
- Vessels: small to medium, uniformly distributed; seasonal growth zones often evident; tyloses; vessels appear pink-yellow due to associated parenchyma and deposits when viewed by lens in cross section.
- Parenchyma (soft tissue): abundant and diffuse, containing deposits and some resin.
- Rays: fine, visible only with a lens.
Other features
- Burning splinter test: match-size splinter burns slowly to charcoal with no ash.
Research and resources
- Boland, DJ, Brooker, MIH, Chippendale, GM, Hall, N, Hyland, BPM, Johnston, RD, Kleinig, DA and Turner, JD 2006, Forest trees of Australia, 5th ed., CSIRO Publishing, Collingwood, Australia.
- Bootle, K 2005, Wood in Australia: Types, properties and uses, 2nd ed., McGraw-Hill, Sydney.
- Ilic, J 1991, CSIRO atlas of hardwoods, Crawford House Press, Bathurst, Australia.
- Queensland Government, DAF 2018, Construction timbers in Queensland: Properties and specifications for satisfactory performance of construction timbers in Queensland. Class 1 and Class 10 buildings, Books 1 & 2, Department of Agriculture and Fisheries, Brisbane.
- Standards Australia, 2000, AS 2082—2000: Timber—Hardwood—Visually stress-graded for structural purposes, Standards Australia International, Strathfield, NSW.