Designed in 1960 by the N&W as the H-11 class which is an enlarged PRR H-39 70-ton hopper. In 1964, the size was increased to 12' 3" high, cubic feet increased to 3433 and weight capacity increased to 90-100 tons. Over 130,000 have been built. Three distinctive characteristics highlight this class of hopper: roping eye with integral end buffers, end slope sheets that are at a steeper angle than the hopper sheets, and 13 riveted side posts with the middle two panels wider than the rest. Other features include wine door locks and full-height side ladder stiles.