It is a motor driven mechanical compactor useful for soil compaction into 100mm or 150mm dia moulds. Two sets of rammers are provided, one of 2.6kg. And the other of 4.89 kg arranged for 310mm and 450mm fall respectively. For compaction soil into 150mm dia moulds, 100mm face dia rammers having weight of 4.89Kg is used. Where as for 100mm dia moulds, they are of 50mm dia. The rammer assembly is provided with a ratchet and pawl arrangement to lift it from the top of the soil layer. When the rammer reaches the required height the pawl release the rammer, which falls freely on soil surface. The release mechanism is connected by an arm moving up and down which is connected to a reduction gear coupled to the motor through another arm. An automatic blow counter fitted to the compactor is used to set the number of blows. The base plate of the specimen mould is to be fitted to the rotating base plate of the instrument which makes 1/5th revolution per operation. Operation on 230 volts, 50 cycles, single phase, A.C. supply, Moulds are to be ordered separately.