Site Problem:

Installation of Steel stairs on the 64th floor in one of the highest towers in KAFD. The installation presented challenges due to the weight of the load and due to access issues.

The weights of the various steel stair pieces, ranged from 300 to 1000kg, making manual installation not possible.

The service elevator’s capacity was less than 2.5ton and the length was only 3m, so arranging large lifting equipment was not feasible.

Solution:

Spider Plus did the site survey and after checking all site conditions, obstacles and access problems, we were able to propose the following solution to effectively undertake the installations. We went with a mini spider crane that can lift more than its own body weight. A crane that only weighs 2T, but can lift up to 2.9T. We went with the URW295 mini spider crane.

Why Spider crane URW295?

1. Can fit in the lift
2. Compact enough to move through corridors
3. Self-weight within the range of the service lift
4. Load capacity and boom length is enough for the installation
5. Small outrigger reactions – lower ground bearing pressures

Procedure involved in installation

1. Spider crane set in center of the floor
2. The pieces of the steel spiral stairs were brought in pieces using jack trolleys.
3. Web slings were used to lift the pieces of stairs by spider crane to assemble
4. Pieces of stairs were assembled by welding
5. The weight of steel pieces was from 300kg to 1000kg.
6. The height of the spiral stair was up to 7m