16' Lowboy Trailer Plans. 7,000 lb gross capacity. The effective bed length is 16' and the width is 6'6". Empty weight is 1800 lbs and tongue weight is 180 lbs. The 14" high side rails are made of square tubing and the lower frame is angle. Steel is optional for this wooden deck trailer. Ramps are stored in easy access rear pockets. Ramps have variable placement. Fender braces double as side steps. Square tubing tongue with 2" ball coupler. Two 3500 lb axles with leaf springs make up the tandem assembly. One or two axle brakes optional. Three big sheet with Seventeen steps to build this heavy duty 16' lowboy trailer.