The wire mesh and centertube are epoxy-bonded to the end caps .
该丝网和中心管是环氧树脂粘结到去年底的上限。
2
They stacked rocks with center holes (tube or doughnut shaped) from the surface to the deep stone layer as a guide for their drills (similar to today's guide tubes).
管状或中空管状的中心孔从地表到深石岩石层放满石头，以作为铁转的探头，作用类似今天的导管。
3
Then, cable lugs used through the traction rope sleeve center small LN tube pulled out.