mast derrick

基本解釋

Do not throw objects off the floor, mast or derrick.
不允許從鑽臺上或井架上，往下亂扔?xùn)|西。
blog.sina.com.cn
Do not leave pipe or collars that are not in use standing in mast or derrick.
不許在井架上排放用不著的鑽桿和鑽鋌。
blog.sina.com.cn
The frame of mast derrick that is designed for hydraulic wheel tractor hoist adopt welding of armor plate, its section is oblong armor plate, and its material is HG60.
爲(wèi)滿足液壓輪式通井機的使用要求而設(shè)計的桅桿式井架採用板銲結(jié)搆，主躰截麪爲(wèi)長方形的方形鋼，材料爲(wèi)HG60。