engineer reconnaissance of the enemy, terrain and objects; construction (arrangement) of fortifications (trenches, ditches and communication trenches, shelters, bunkers, dugouts, etc.) and organization of field deployment of troops (residential, logistical, medical); organisation of engineering obstacles, including installation of mine fields, production of blasting, organisation of non-explosive obstacles (anti-tank ditches, scarps, counterscarps, stakes, etc.); clearance of areas and facilities; preparation and maintenance of traffic routes of troops; creation and maintenance of ferries across water barriers, including construction of bridges; extraction and purification of water in the battlefield