Clinker silo steel structure – Case Study

Project execution: 

A 650t crane was rigged up and lifted the ring beam assembly above the silo. Stay cables were used to secure the ring beam at 44m. Two 250t cranes are used to connect the rafter assembly (25t each). Once the rafters have been assembled, the silo’s load is gradually released.

The entire penthouse set (150t) of dimensions (15m x 15m x 22m) is lifted and placed on top of the ring beam with a rafter.

As per the scope we initially lifted the 40m long conveyor in tandem with 450t and 250t cranes and erected it over the existing column and silo.

Challenges of the project:

• The main crane had to hold the ring beam above the silo for 15 days. During these days, the rafters and purlins were installed, increasing the load from 70t to 135 tons.
• The rigging arrangement of the penthouse assembly was designed to lift the load with minimal stress on the steel structure. Detailed load analysis was done, and counterweights were added to the structure to ensure the COG of the load remained at the centre of the structure.
• Since the site is near a mountain, the wind speed created a tunnel effect, and the load surface area is also large, we had to calculate the permissible wind speed.
• To complete the project, a complex rigging system was created.