derrick boom

基本解释

Otherwise, adjust the derrick boom. Fix the shaft seat on top, and fix the shaft at bottom.
推动门扇应滑动顺畅，否则调节吊轮的吊杆、上固定转轴座、下固定转轴。
The opening hatch cover method also not to be satisfied that using the warping head of cargo gear not through derrick boom open the hatch cover because using derrick boom is not safe.
开舱盖的方法不令人满意，起货设备传动轮弯头在开舱时不穿过吊杆，原因为使用吊杆不安全。
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The derrick boom rests to be renewed as Chief Officer requirement because the rests are too high and too thin and not safety for navigation. Also the deformed positions to be corrected.
吊杆支座应按大副要求换新，因为支座太高、太薄不能满足安全航行，同时需纠正变形。
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