The first girder: the bridge girder launcher can erect the girder independently without any auxiliary measures. While erecting the first girder, the position of the rear support leg bridge girder launchermeets the design requirement.

The last girder:

Step 1: Start the hydraulic pump station of the front support leg, pull back the cylinder of the front support leg. Rotary pull the front support leg manually.

Step 2: Shut down the hydraulic pump station of the front support leg. After the launcher is steady, start the hydraulic pump station of the front support leg. While erecting the last girder, the position of the front support leg meets the design standards.

Step 3: Shut down the hydraulic pump station of the front support leg. Transport the guide beam with the trolleys and the traveling mechanism of the auxiliary support legs. After the launcher has travels half of the span, lifting the guide beam off the piers with the auxiliary trolleys and the drive mechanism of the auxiliary support leg.

Step 4: The launcher works normally as the described operation manual.

6.4 The accuracy requirements under different construction conditions