Abstract: Surface towing sack, a new vehicle for fuel transportation, is a cylindrical container. It is made of rubber and carries fuel or fresh water by floating on water. It can be used as a substitute for small barge or tanker and has unique advantages. The paper introduces the SURN 90-50 Towing Sack, including its working conditions, strength requirements, and technical specifications (oil resistance, wear hardness, maintainability, etc.). It consists of a sack, air blower, etc. The working principle for each unit is discussed. It is confirmed by China's experts that this system has such advantages as high safety and reliability, reasonable design, high quality, advanced technology, wide applicability, and high military, economical and social benifits.