Jamshedji Construction Machinery Co. Supplies Self-Travelling Double Beam Screed Vibrator. Jamshedji Construction Machinery Co. Is an ISO 9001: 2008 recognised company manufacturing a wide range of construction machines like pumps, mixers, cutters, rollers, rammers and vibrators. The Self-Travelling Double Beam Screed Vibrator only requires guiding along the formwork and is dragged by two operators. The Self-Travelling Double Beam Screed Vibrator does not need to work in concrete and is operated by electronic drive motor of 2 H.P.