The flow-line method adopts the combined double-block sleeper model and produces the sleepers on the assembly line according to the prescribed technological process.

To make a double block sleeper, a steel wire or bar is installed in a removable modular sleeper model, stretched, then filled with concrete and vibrated on a specially designed long gauge vibrator. After the vibration is completed, it is moved into the steam curing pit for wet and hot curing. After the concrete has hardened and reached a certain strength, loosen the steel wire or reinforcement and release the mold. This technology is mainly used in the production of prestressed concrete twin block sleeper in China.

The process characteristics of the current sleeper assembly process in China are as follows:

1. Using the 2x5 combined model, 10 double-block concrete sleepers can be formed at one time. 2. In order to adapt to the 2 x 5 combined model, 1 x 5 combined vibration table is adopted, which is equivalent to each pair of parallel double-block sleeper cloth! A unit countertop.
3. The molding of concrete double-block sleeper adopts the technology of secondary vibration.
4. The twin-block sleeper assembly line generally adopts roller conveyance, forming an annular closed technological process, realizing the continuity and rhythm of the twin-block sleeper production process, and reducing the non-productive transportation in the workshop.
5. The current double-block sleeper assembly line has gradually developed into a multi-functional assembly line.