汽车单车原木运输时,目前普遍采用封顶绳(钢丝绳或铁线)防止车箱板外张,打结后用绞杠或手动棘轮绞紧。这种方法的缺点是:①装好原木再揽封顶绳,车箱板在装车过程中已受原木挤压而外张。封顶绳不可能使外张的车箱板恢袋原状。另外由于人力揽结封顶绳张紧力不足,在行车途中车箱板会继续外张,长此以往车箱板会过早损坏。②当前伐区、贮木场装卸车 At present, the top rope (wire rope or wire) is used to prevent the outside of the trunk plate from being stretched out when the bicycle is transported by wooden logs. After the knot is tied, the strangle or the manual ratcheting is tightened. Disadvantages of this method are: ① installed wood again enveloping ropes, car plate in the loading process has been squeezed by the logs outside. Rope can not be outside the top of Zhang Caibao restitution. In addition, due to lack of manpower knot cap rope tension, in the traffic car plate will continue to Zhang, the long run will be premature damage to the board. ② cutting area, storage yard truck