The OMS model WD 28 – 43 bottom drive Wick Drain Installation Machine (WDIM) is designed to insert the wick into the soil and extract mandrel from the ground. WDIM is using vibratory (dynamic) forces and static forces while operating. When the sprocket drive is used, the mandrel sees only static forces. The vibro is activated when dynamic force is needed to insert the wick into tough soil. The model WD 28 – 43 WDIM operates in a frequency of up to 2000 vibrations per minute to provide maximum wick mandrel penetration rates in a wide variety of soils.