Bridge Girder Launcher

(1)Feed-in girder

1.Before feeding-in girder, check rear part support of bridge construction machine to avoid excessive subsidence at rear part of the machine when feeding-in girder

2.As transporting girder, there should have someone to pay attention to support to avoid colliding with bridge construction machine. And there should have someone to be responsible for operating girder transporter

3.As transporting girder, it is forbidden to have workers standing on rear part of the girder or scaffold floor to avoid falling objects hurting someone

4.When bridge construction machine begins to feed girder, the girder transporter should push in the girder slowly. At  the meantime, appoint someone to watch it so that the girder will not collide with transporter or bridge construction machine

 

(2)Bundle girder

1.as bundling girder, install and align iron tile on both sides to make wire rope in the center of iron tiles. Check whether wire rope ties a knot, twists or hitches with a stem or some else

2.the distance between hoist point and end point of the girder on one side should be equal to another side so that the winch will not overload for unequal carrying capacity

3.Jack line to bundle the girder should keep vertical and an inclined hanging is forbidden. It is forbidden to vertically or horizontally push iron carrying pole by brute force to hang jack line so that as lifting girder violent swing won’t happen or sudden slip of wire rope to cut off steer wire and crush girder is avoided

 

 

(3)Lift girder

1.Trying to lift girder once is needed before operating any lifting girder. Named, after bundling the girder, the winch should have brake test for 2-3 times, then lift girder a little to check whether wire rope is in slot position and iron tile to protect girder leaps up and moves off or not. If not, it can work.

2.The winches should act in an unified way and with an even carrying capacity. Phenomena such as overload and violent swing for precast girder are strictly forbidden.

3.It should maintain a level to lift, move and drop the girder. If it is founded an incline, adjust it at once. In order to have a convenient dropping girder, sometimes it is allowed to have a little but not big longitudinal incline.

4.Phenomena such as disordered reel and slot position of wire rope, crushed and broken cable are avoided. All obstacles to prevent girder from moving must be cleaned off.

5.The precast girder should move in a higher position. Moving in a lower position is easy to have an accident due to violent swing

6.As moving the girder, there should be specially-assigned personnel on piers to monitor operating situation of precast girder. especially when the girder will move to the exact position, monitoring personnel, commanding personnel and driver should be in careful and close cooperation to avoid girder from colliding with front outrigger. If necessary, monitoring personnel on abutment could pull limit switch to keep a safe environment.

7.The bridge construction machine is forbidden to lift girder with overload. 

 

(4)Drop girder

1.it is forbidden not to take measures to jack and pull horizontally the girder when dropping girder is done

2.as dropping girder, there must have chain hoist at front and rear part as a protective measure. The chain hoist must be fixed in a firm place.

3.When there is a distance of 200-300mm between girder and support, affirm support and transverse equipment are in order, then dropping girder could be continued.

4.When dropping girder is ready, two lifting jacks on one end should be in a synchronous up and down to avoid accidents for inclined precast girder.

5.When bridge construction machine horizontally moves the girder, there should have someone to monitor transverse moving trolley. When the girder is installed, use wedge aor wheel stopper to fix travel wheel of trolley to avoid sliding.