Autranella congolensis
Family: Sapotaceae
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Mukulungu

 

Other Common Names: Elanzok, Elang (Cameroon), Kabulungu (Zaire).

 

Distribution: Widely distributed throughout the dense equatorial forests.

 

The Tree: Reaches a height of 120 ft and more; boles straight, cylindrical, and clear to long lengths; trunk diameters 4 to 6 ft; sometimes buttressed.

 

The Wood:

General Characteristics: Heartwood red to reddish brown with darker streaks; sapwood grayish, not always sharply demarcated from the heartwood.  Texture is fine and even grain usually straight, sometimes interlocked; somewhat lustrous.  Dust is very irritating to mucous membranes.

 

Weight: Basic specific gravity (ovendry weight/green volume) 0.78; air-dry density 60 pcf.

 

Mechanical Properties: (2-cm standard)

 

Moisture content   Bending strength   Modulus of elasticity   Maximum crushing strength

            (%)                  (Psi)              (1,000 psi)                     (Psi)

12% (44)                     21,800            NA                              12,700

 

12% (44)                     23,000            2,150                           11,900

 

Amsler toughness 282 to 398 in.-lb at 12% moisture content (2-cm specimen).

 

Drying and Shrinkage: Seasons slowly and should be quartersawn to minimize degrade. No information available on kiln schedules. Shrinkage green to ovendry: radial 5.8%; tangential 7.4%; volumetric 14.8%. Reported to have a large movement in service.

 

Working Properties: Saws and machines fairly easily but with dulling of tools due to silica content; dresses to a smooth finish; difficult to glue; good ventilation is required to remove irritating dust.

 

Durability: Heartwood is rated as very durable though there may be slight termite attack. Resistant to dilute acids. Good weathering characteristics.

 

Preservation: Highly impermeable.

 

Uses: Heavy construction, flooring, furniture and cabinetmaking, acid vats,  turnery, joinery.

 

Additional Reading:  (3), (14), (44)

 

3. Bolza, E., and W. G. Keating.  1972.  African timbers-the properties, uses, and  characteristics of 700   species.  CSIRO.  Div.  of Build.  Res., Melbourne, Australia.

14.  France: Bois For.  Trop.  1954.  Mukulungu (Autranellaa congolensis).  Bois For.  Trop.  36:25-28.

44.Sallenave, P. 1955.  Proprietes et mecaniques des bois tropicaux de l'union  Francaise.  Pub.  Centre    Tech.  For.  Trop.  No.  8.

 

From: Chudnoff, Martin. 1984. Tropical Timbers of the World. USDA Forest Service. Ag. Handbook No. 607.