1820 150 foot Truss Bridge Kit. The 1820 N Scale Truss Bridge with Walkways & Railings is a beautifully detailed kit. She is a one of a kind beauty, and we believe that N Scalars will love to add her to their existing layout or even have it to display as a trophy on their desk or mantel! Vertical Clearance: Approximately: 1.75" (code 81 rail head) 23' 4" (160th scale) Length (end to end): Approximately: 11 15/32" (over-all) 153' (160th scale) Length (shoe- shoe): Approximately: 11 1/4" (center - center) 150' (160th scale)