How to reconnect overhead crane main girder segments?

Apr 01, 2021

 In actual design, overhead crane main girder length(span) has to suit the width of workshop. Most of the time, its span more than 11.9m.

However, the max inner length of one 40' container is 11.9m. For convenient transportation in container, we have to implement segmented design of main girder.

For example, one overhead crane main girder has a span 20m, then we will design the main girder as 11m &9m segments. At end of segment girder, flange plate with match drill holes are welded for future connection.

After fabricating is finished, main girder segments are connected with high strength bolts.

The connection between main girder and main girder, between main girder and end girder shall use high strength bolts .  

High strength bolts pre-tightening torque shall follow below chart:

Bolts materials Bolts type	M16	M20	M22	M24	M27	M30
8.8 grade	190	370	500	640	950	1300
10.9 grade	265	520	700	900	1350	1800

Please note:

1. In design, Kevino fully consider the camber of main girder after connection;

2. The segment connection position has to avoid mid-span, because mid-span bears the largest load in operation;

3. Bolts connection between main girder and main girder shall be M24,10.9 grade,  the pre-tightening torque value shall reach 900;

4. Bolts connection between main girder and end girder shall be M20, 10.9 grade, the pre-tightening torque value shall reach 520.

Above is brief introduction from Brenda in Kevino Crane.

For any more details about us, please feel free to visit our website: www.kevino-crane.com 

For any inquiry please talk with Brenda via:

Email: brenda@kevino-crane.com

Mobile/ Whatsapp: 0086-15290802640