(1) feature
1. without limit of geographical conditions, the simple gantry for lifting girder changes traditional construction way to lift concrete girder by using gantry crane and crane
2. with simple operation and low cost, it solves below problems:
a. gantry crane can not be transferred to any site, with assembly and disassembly, it costs a large number of labor and material resources
b. for crane, it demands too much on site. and the problem of high cost and low safety exists.
3. the simple gantry for lifting girder features low investment, reliable quality, simple maintenance and convenient transportation
(2) range of application
1. With a wide range of application, the simple gantry for lifting girder can be used in any place with concrete girder.
2. when there is a need for gantry crane in precast yard, the simple gantry will be a affordable choice.
3. when a transporter can not feed concrete girder directly to bridge construction machine, the gantry will lift concrete girder onto platform wagon to help feed girder, quite easy and convenient
4. when there is a temporary need to load and unload concrete girder
(3) advantages
1. compared with gantry crane
For gantry crane, there is a strict demand on site. it costs huge time, labor and material resources. 
As a special equipment, gantry crane could be put in market after being accepted by quality and technology supervision department and after training professional operating technicians
Due to the time limit for a project, a gantry crane will be leaved unused after a short time use. It is expensive
2. compared with a crane
Most concrete precast girder has a weight of more than 100t nowadays, at least 2 sets 60t crane can lift the girder. And only two cranes cooperate with each other well, crane accidents can be avoided, it features a low safety
Two cranes costs more .
(4) structural behavior
The gantry is welded of section steel and steel plate. With 4.5m span, the girder transporter can drive into the gantry, then the gantry lift concrete girder onto it. Usually span of the gantry is from 4.2m to 5.2m according to width of concrete girder
Under landing leg, there is a cross girder. Under cross girder, the wheel box is fixed. Jack cross girder with cylinder and hydraulic jack, than pull the wheel box ,the purpose of steering can be achieved
 
 
(5) economic benefit and application
1. With the low cost, the simple gantry can be used. repeatedly
2. It features light self weight, high safety, small power consumption, high efficiency, simple structure, convenient operation and strong adaptability.
3. it is specially suitable for construction site with small area, complicated terrain and less girder
To sum up, it received a good economical and social benefit to popularize the simple gantry for lifting girder.