In the application of drilling machinery, the air-leg rock drillcan only drill small-aperture, medium-shallow blast holes; the heavy-duty rail-type rock drill can also drill deep blast holes through the post, but the en.
[pdf] Kulluk was an ice-strengthened that was used for oil exploration in the Arctic waters. She was constructed by in in 1983 and operated in the Canadian Arctic until 1993 when she was mothballed for over a decade. In 2005, she was purchased and extensively refurbished by Shell PLC for drilling off the .
[pdf] The and the topsides of the Perdido were constructed separately and then assembled in its final position in the Gulf of Mexico. The Perdido's hull or spar was constructed by in . A barge shipped the 22,000 tonne spar 13,200 kilometres (8,200 miles) from the to the Gulf of Mexico. After floating the spar, it was towed to its final home above the Alaminos canyon 320 kilometres (120 miles) fr.
[pdf] 
