2.1  跨度 S                                                                                                                                                                   2.2  起重機高度 H                                                                                                                                                      2.3  起重機寬度 B  Crane width  起重機運行方向前后最外端的距離                                                                      2.4  小車軌距 K                                                                                                                                                          2.5  大車（起重機）基距 W                                                                                                                                        2.6  小車基距 W c                                                                                                                                                      2.7  緩沖器高度 H 1  Buffer height  大車緩沖器縱向中心線到起重機軌道頂面的距離                                      2.8  主梁底面位置 H 2  Position of bottom plan of main girder  主梁底面到起重機軌道頂面的距離                      2.9 司機室底面位置 H 3  Position of bottom plan of cab  司機室底面到起重機軌道頂面的距離                            2.10 主鉤上極限位置 H 4  Main hook approach to cane rail top  主鉤最高位置到起重機軌道頂面的距離          2.11 副鉤上極限位置 H 5  Auxiliary hook approach to cane rail top  副鉤最高位置到起重機軌道頂面的距離      2.12 主鉤左極限位置 C 1  Main hook approach to cane rail top （ left side ）  從傳動側看，主鉤橫向左極限位置
2.13 主鉤右極限位置 C 2  Main hook approach to center of crane rail （ right side ）  從傳動側看，主鉤橫向右極
2.14 副鉤左極限位置 C 3  Auxiliary hook approach to center of crane rail （ left side ）  從傳動側看，副鉤橫向左極限位置  
2.15 副鉤右極限位置 C 4  Auxiliary hook approach to center of crane rail （ right side ）  從傳動側看，副鉤橫向右極限位置    
2.16 司機室水平位置 L 1  Distance between cab and rail  司機室外端離起重機軌道中心線的距離                       2.17 司機室底長 L 2  Bottom length of cab  司機室底部長度                                                                                    2.18 起重機軌道中心至起重機外緣距離 b  Dimension from rail center to crane edge  起重機橋架方向的外緣離起重機軌道中心線的距離   
2.19 主梁上拱度  camber  主梁預制的由水平線算起的向上拱起量