sentences:  A teleradio consisted of a transmitter, a receiver and a loud speaker, which were transported in three metal boxes measuring 60cm x 30cm x 30cm.They were powered by car batteries, which were charged by a petrol engine weighing 30 kg.Moving them was difficult, requiring 12–16 indigenous people to help carry them.Feldt then conceived the necessity of the positioning of Coastwatchers so that they formed a virtual fence reaching from the Dutch border with New Guinea to the eastern side of the Solomon Islands.