This is a very recent and sad story and it breaks my hearth to write about it. Today Hürriyet newspaper reported about an attempted sabotage on board of Turkish submarine TCG Gür.
I am sure that, we will hear more about it in the coming days, but as today the story is as follows:
A petty officer, whose name is withheld, was on watch at 30th December 2016 on board of submarine TCG Gür. He made several (unauthorized) trips to the machinery department and dropped pieces of metal, nuts and similar things into the main diesel engine of the submarine.
The petty officer was arrested on charges “attempt to destroy the sea transport vehicle belonging to the State’s Armed Forces'” on 5th January 2017.
I am happy to hear that there was no damage to the submarine and at the attempted sabotage was thwarted.
TCG Gür is the first boat of the second batch Type 209/1400 class submarines. She is commissioned in 2003 and is one of the most advanced submarines in our navy.
devrimyaylali.com 
Very sad state of affairs !
A sad development indeed. Hopefully, this was a lone incident, by a troubled man. And, not anything else.