The pipe racks are moved to and from their stored position by a hydraulic cylinder attached between the mast frame and the lower swing arm.

管架是通过一个装在支架框和下摇动臂之间的液压缸往返于其贮存位置的。

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The swing arms are fastened to the inside structure of the mast, and permit the pipe rack to be low-ered from the stored position to the centerline of the drill string.

两个悬臂则固定在支架的内部结构上，并允许管架从贮存位置降到钻柱中线上。

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