| 摘要 |
Structures and apparatuses such as tank cars that have ladders associated therewith are disclosed which have, at the ladder top, two arrays of a plurality of horizontal rungs suitable for a climber using a ladder to horizontally grip by hand. The arrays form an opening through which a climber can leave or access the ladder while gripping the horizontal handgrip rungs of the arrays. The cross-section of the horizontal handgrip rungs is substantially round and should not exceed 2 inches in diameter. The preferred cross-section of the rungs is within the range of from about ¾''-1 '' in diameter.
|
