T-18, the new FRA Gage Restraint Measurement System (GRMS) vehicle procured in May 2004, is a state-of-the-art deployable GRMS vehicle which utilizes a 5th split railroad axle to laterally load the head of both adjacent rails of railroad track in order to measure rail motion under a combined vertical and later load for the detection of weak ties and fasteners. It has a unique suspension system which maintains alignment and apply continuous loads perpendicular to the rails regardless of the roll, pitch or vertical movement of the carbody on its suspension, or the curvature of the track; lifts and lowers split axle for testing and stowage; and orients split axle so that wheels are tangent to rails as track curvature varies.