a locomotive underframe cng fuel storage system including : a crashworthy enclosure including a removable side panel and a permanent side panel welded into place ; and at least one cng cylinder module , wherein each cng cylinder module includes a plurality of cng cylinders stacked vertically , secured to a vertical wall , and separated by a horizontal plate , wherein the horizontal plate extends towards but does not contact the vertical wall when the vertical wall is planar and , further wherein , the horizontal plate supports the vertical wall from moving further out of plane when vertical axial weight causes the vertical wall for move out of plane towards the horizontal plate .