Ramky Engineering and Consulting Services has started the construction work on the Gabon special economic zone (GSEZ) in West Africa. The Rs 380-crore project is on a turnkey basis and involves design, engineering, procurement and construction of the 1,000 acre SEZ. GSEZ is a joint venture between the Gabon government and Singapore-based OLAM, a commodities trading company. Ramky would develop internal infrastructure, including, boundary wall, fencing, landscaping, roads, and drainage, a release said.