Mining capsule

Mining capsules were used to survey extreme environments and could be locked with a six-digit alphanumeric entry coder.

Ruslan locked River Song in one due to her interfering in his mining projects and later had Helen Sinclair join her due to his distrust of her. River was unsuccessful at guessing the key code and was only able to escape when Helen produced the Eighth Doctor's sonic screwdriver.

River and Liv Chenka locked the Eleven in one after River defeated him with Venusian aikido. He was saved by the Sonomancer and placed in his TARDIS. (AUDIO: The Sonomancer)