国内外林业企业都广泛地采用龙门起重机与装卸桥进行木材的装卸作业。截至1977年底苏联森工企业一共投产了3350台龙门起重机、装卸桥和塔式起重机,其中900多台装卸桥和塔式起重机采用了抓具装置。目前我国林业企业已采用了几 Domestic and foreign forestry companies are widely used gantry crane and loading and unloading of the bridge for loading and unloading operations. As of the end of 1977, a total of 3,350 sets of gantry cranes, loading and unloading bridges and tower cranes were put into operation by the Soviet Union’s industrial and mining enterprises, of which more than 900 were used in the loading and unloading bridges and tower cranes. At present, China’s forestry companies have adopted a few