derrick floor sills是什么意思

用法例句

Natural vibration analysis of the drilling platform of ZJ30/1700CZ rig;

ZJ30/1700CZ钻机钻台固有振动特性分析

8 meters, while the foundation tower above the ground a certain distance and have a certain breadth, workover drill floor cannot span the foundation to set down.

8米,而抽油机基础又高出地面一段距离,并且具有一定的宽度,现有的修井钻台不能跨跃基础摆放,必须拆除基础才能进行大修作业。