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| Name | Azobé |
| Other names | aba (Nigeria), akoga, akogha, akoura (Gabon, Guinea), azobé (Ivory Coast, France, Germany), Aya (Congo, Zaire), bongossi, (Cameroon, Germany), bakundu (Cameroon), bonkolé (Congo), eba (Nigeria), ekki (Nigeria, UK), endwi (Sierra Leone), esore (Ivory Coast), hendui (Liberia, Sierra Leone), kaku (Ghana), okoga (Cameroon). |
| Botanical Name | Lophira alata Banks ex Gaertn.f. (= L. procera A. Chev.). |
| Family | Ochnaceae |
| Origin | Tropical West Africa. |
| Tree Description | Grows to heights of 40 m (max. 50 m) with 25 to 30 m long, often oval-shaped, branch-free trunks and often a slight curvature. Diameters range between 1.5 and 1.8 m and the trunk base is often somewhat swollen. |
| Available As | Azobé is most often imported into the Netherlands as raw timber in lengths of 4 to 10 m, diameters of 0.5 to 1.5 m and sawn to size on order. Gradually, more timber sawn to size and finished products (sheetpiling) are being imported. |
| Wood Description | Heartwood when newly cut is reddish brown and discolours to dark red or chocolate brown, or even to a violet/dark red. Azobé has striking whitish yellow particulates in its pores. In general, the structure is fairly even. Interlocked grain results in alternating light and dark stripes in quarter-sawn surfaces. Plain-sawn surfaces show a vague striped patters caused by colour differences between fibres and pith. A broad 80 to 120 mm lighter-coloured transition zone occurs in freshly cut azobé between the heartwood and sapwood. Once dry, this unhardened heartwood turns the same colour as the heartwood. This transition zone wood is less durable than the rest of the heartwood. The 50 mm wide sapwood is sharply defined and has a markedly lighter colour than the heartwood. |
| Wood Type | Hardwood |
| Grain | Most often interlocked or irregular grain. |
| Texture | Coarse |
| Density | 940/1060/1100 kg/m3 at 12% humidity, 1100 to 1300 kg/m3 when green. |
| Working | Major |
| Drying | Very slow. It is advisable to protect the crosscut edges against splitting. Longitudinal splits can also occur rapidly. Azobé is particularly susceptible to distortion when drying (especially thin-cut timber). Given its applications, azobé will often dry out while in situ, which can lead to the abovementioned problems if insufficient attention is paid to such issues. |
| Workability | Despite its hardness, azobé can be machined fairly easily. Machine planing should be carried out with a shallow chip angle due to a strong interlocked grain in order to achieve a smooth surface finish. Freshly sawn timber has a characteristic tannin scent that eventually dissipates. Dry working blunts saws and chisels rapidly. |
| Fixings and Fasteners | Pre-drilling required. Iron has the tendency to corrode when in contact with azobé. |
| Bonding | Potentially problematic given its density. |
| Pliability | Very poor |
| Surface Finishing | Good, although hairline cracks can arise in the surface finish due to working. |
| Durability | Moulds - ground contact 1/2. azobé is very durable (Class 1) in salt and freshwater. The wood in the transition zone between the heartwood and the sapwood has a durability classification 2 (tested in compliance with ENV 807 Method 2). Explanatory Note: SHR Houtresearch Wageningen conducted research into azobé's natural durability on behalf of a group of timber merchants. The outcome of this research classified azobé heartwood into durability class 1/2 and transition zone wood into class 2. Research was conducted in compliance with European testing guidelines as laid down in ENV 807 Method 2. It has been common practice in recent years to apply this testing method to determine the natural resistance of new wood varieties to moulds in contact with the ground. Test results collected in compliance with ENV 807 Method 2, give an impression of the durability of woods in contact with the ground. Since there is no official way of converting natural durability as specified by NEN-EN 350-1 and NEN-EN 350-2 standards, only test values collected by ENV 807 Method 2 can be compared directly with one another. Termites D, marine burrowers D (under conditions found in the Netherlands and Belgium, M (under conditions found in southern Europe). |
| Strength Class | Azobé has been classified as a K70 wood according to NEN 5498:1997 and D60 (NEN 5480:1983, Quality Class A/B) according to NEN-EN 1912:1998. |
| Impregnability | Heartwood 4. Sapwood 2. |
| Peculiarities | - |
| Applications | Azobé is a very heavy, hard wood that is used extensively as construction timber in hydraulic engineering projects such as lock gates, guide piling, weirs, jetties, bridges, bridge decks, sheetpiling, walings, posts and rubbing beams. Wattle constructions made of thin azobé can be used for sheetpiling, fencing, cribs, mats and for road foundations. Other uses include sound barriers, reflector poles, fencing posts, park benches, wedges, keel blocks, bilge blocks, industrial flooring, crossbeams, dragline planking, weighbridge decks, floor ceilings and heavy machinery support structures. Azobé is very resistant to attack by acids and other chemicals, and is therefore particularly suitable for use in system support structures in chemical plants. Azobé is used to make the rails for the rubber-tyred Parisian metro system. |
| Quality Requirements | In 1983, Dutch standards appeared for azobé in the series, Kwaliteitseisen voor hout (KVH 1980), NEN 5480 Houtsoort azobé ['Quality Standards for Wood (KVH 1980), NEN 5480 azobé']. Azobé is listed in Dutch usage guidelines, NPR5493:1999, Kwaliteitsrichtlijnen voor loofhout in waterbouwkundige werken ['Quality Directives for Hardwood Used in Hydraulic Engineering Projects']. |
Source: Houtvademecum, 8e druk 2001