Col (POL Army) Mariusz Ochalski is a graduate of the Railway Technical School in Warsaw , after passing his secondary school leaving exams in 1994 he began his military service as a cadet at the Faculty of Mechanics at the Military University of Technology in Warsaw. In 1999 he was appointed to the position of commander of an engineering machinery platoon in the 1st Brzeski Tadeusz Kościuszko Engineer Regiment . In the following years he served in the same unit in the positions of commander of an engineering machinery platoon, educational officer in the headquarters of the engineering machinery battalion and deputy commander of an engineering company. In 2002 he took over the duties of commander of an engineering company, which he held until 2007. As part of the SON duty, commanding an engineering company, he participated with his sub-unit in the mission to help the North Atlantic Alliance after the earthquake in Pakistan in October 2005. In 2007, he took over the duties of chief of staff of the engineering support battalion in the 1st Engineer Regiment, and at the end of 2007 he began his service as a specialist in the Command of the Engineering Troops, DWLąd, where he was responsible for preparing engineering subunits for SON duty and participation in the MINURCAT mission in Chad . In the period from July 2010 to July 2013 he served as head of the training team at the Military Engineering Centre of Excellence (MILENG COE) in Ingolstadt, Germany. Since August 2013, he has been a specialist in the Command of Military Engineering in Warsaw, and after the change in the command structures of the Polish Armed Forces, in the Military Engineering Directorate (ZIW) of the Inspectorate of the Branches of the Military of the General Command of the Branches of the Armed Forces. From October 2014 to September 2017, he commanded an engineering support battalion in the 2nd Mazovian Engineer Regiment named after Maj. Gen. Tadeusz Kossakowski, alias "Krystynek" . From September 2017 appointed to the position of senior specialist in the Operational Department of the ZIW. From December 9, 2019 appointed to the position of commander of the 5th Engineering Regiment in Szczecin - Podjuchy . Currently, he serves as Deputy Head of the Military Engineering Directorate of the General Command of the Branches of the Armed Forces.