Tesmec supplied the 1st CTSU to the Chinese market in the year 2005 and since then over 30 units have been supplied to all the main Chinese railway construction companies. In the past 10 years around 30000 kilometers of high-speed railway lines have been built in China, of which over 60% were electrified with Tesmec Constant Tension Stringing Units (CTSU).

In 2011 the Chinese National Railway Standard “Constant tension cable unrolling vehicle for overhead contact system in electrification railway” was drafted based on the technical specification of TESMEC CTSU Mod.CFB546 by the former China Railway Minister (now China Railway Cooperation).

Tesmec CFB546 was also used for the construction of the Beijing-Shanghai high-speed passengers dedicated line (PDL). With a total length of 1.318 km, it is the world's largest PDL project and it is the world's longest high-speed line ever constructed in a single phase.