The trolley traveling system of all the bridge cranes and gantry cranes designed and manufactured by HXME are developed based on digesting and absorbing foreign advanced technology, combine with years of technical research and development experience of the relevant Institutes, and in compliance with GB/T3811-2008 "Crane Design Specification" GB/T14405-2011 "Universal Bridge Crane" and other standards, and by referring to relevant foreign crane standards and the mainstream models of bridge crane prevailed by the European Handling Association. It is energy-saving and emission reduction, economical and environment-friendly, especially suitable for underground factories, new factories and hoisting, transporting, moving large tonnage valuable objects in place. The first bridge crane designed by HXME team was the 80/20t bridge crane in Ningbo Beilun Power Plant, which was developed in year 1990 and put into operation in year 1992. The first gantry crane was 2x20t gantry crane supplied to Fuchunjiang Power Plant in year 1994. In the past 30 years of development, it has provided more than 1,000 units of bridge cranes and gantry cranes to many big companies at home and abroad. It is the most advanced and most mature low-clearance trolley structure in the industry in China. The single-trolley bridge crane ever manufactured by HXME is with maximum rated lifting weight of 800t, and the double-trolley bridge crane is with maximum rated lifting weight of 500t+500t. HXME has the design and manufacturing capacity of 1500t bridge crane; The gantry crane ever manufactured by HXME is with maximum rated lifting weight of 900t shipbuilding gantry crane.