marek tesina (asker) Dec 5, 2012:

Bohužel žádný kontext není, ale váš návrh by dával smysl. Uvidíme, jestli na něco nepřijdu já nebo některý z kolegů. Zatím díky.

Ales Horak Dec 5, 2012:

nemáte k tomu kontext? řekl bych, že je to skluz na trubky:

On a typical drilling rig as at 14, a hole 22 (commonly designated the "mouse hole") is located between the power-driven rotary table 23 and an inclined platform or so-called "pipe skid" 24 which is positioned between the pipe rack 15 and theadjacent edge of the rig floor 13. Thus, for convenience, the pipe-handling apparatus 10 includes an upright portable mast 25 which is inserted in the mouse hole 22 and suitably braced or secured below the rig floor 13 as required to maintain the mastin a generally-upright position. A ring 26 is arranged near the upper end of the mast 25 for securing the cable 16 at a selected height above the rig floor 13.