We are principally engaged in the provision of vessel chartering services to transport dry bulk cargo. As at 31 December 2018, we own and operate a fleet of 70 vessels consisting of tugboats and barges which mainly navigate waters around the Indonesian archipelago.
Our tugboats and barges are used to transport mainly thermal coal, sand and other quarry materials, with the transport of thermal coal from coal mines to thermal power stations and cement companies which operate their own thermal power plants in Indonesia. We enter into freight or time charters which range from a period of one to five years. Our freight charters typically involve domestic routes in Indonesia from Kalimantan to various ports in Java and Sulawesi while our time charters involve mainly domestic routes around the Sumatra Island.
Our fleet of tugboats and barges has an average age of less than 16 years which is the estimated useful lives of such vessels under normal wear and tear conditions. All of our tugboats are installed with Global Positioning System (GPS) to assist in deploying our vessels more efficiently as the GPS enables us to track and monitor the routes and locations of our vessels on real time basis.