The crane size was mostly met the loading requirements from value="80" tcsc="0" unitname="kg" w:st="on">80kg to value="5000" tcsc="0" unitname="kg" w:st="on">5000kg. And the bevel edge design enables the travelling trolley among the different tracks keep a better conformity, and decrease the possibility for dust accumulating on the tracks, which makes the trolley move much more smooth, as well share a longer service life. Compared to the other cranes, the operating force YKL-Track needs is less than 5 times. Besides, a retractable girder could be applied, as well, usually used in containers, trucks and the cross train situations.