1. Design of Gantry Girders

2. Components of an Overhead Crane

3. Crane Notations

4. Data For Overhead Cranes
Load and other details of crane should be obtained from the manufacturers of cranes.

5. Typical Data for 40t Crane

6. Loads on Gantry Girder

7. Impact Loads

8. Maximum Load Effects

9. Max. S.F., B.M., and Deflection

10. Two Cranes at the Same Span

11. Max. BM for Two Cranes At the Same Span

12. Limiting Deflection

13. Profiles Used for Gantry Girders

14. Steps for Design
Assume that the lateral load is resisted entirely by the top flange of the beam plus any reinforcing plates, channels etc. and the vertical load is resisted by the combined beam.
Find the maximum wheel load: This load is maximum when the trolley is closest to the gantry girder. Increase it for the impact
Calculate the maximum bending moment in the gantry girder due to vertical loads.
To simplify the calculations, add the maximum bending moment due to dead load to the maximum wheel load moment

15. Steps for Design (cont.)
4. The maximum shear force is calculated. When the gantry is not laterally supported, the following may be used to select a trail section.
Zp = Mu / fy Zp (trial) = k Zp (k = )
Economic depth ≈ 1/12th of the span.
Width of flange ≈ 1/40 to 1/30th of the span
5. The plastic section modulus of the assumed combined section
Mp = Zp fy
where Zp is called the plastic modulus

16. Steps for Design (cont.)
6. Check for moment capacity of the whole section (as lateral support is provided at the compression flange) Mcz = βb Zp fy ≤ 1.2 Ze fy / γm0 <Mu 7. Check top flange for bending in both the axes using the interaction equation (My / Mndy)+ (M2/Mndz) ≤ If the top (compression) flange is not supported, Check for buckling resistance in the same way as in step 6 but replacing fy with the design bending compressive stress fbd.

17. Steps for Design (cont.)
9. Check web of the girder at points of concentrated load for local buckling or local crushing, and provide load carrying/ bearing stiffeners, if necessary.
10. Check for deflection under working loads

18. THANK YOU!