Kariba Dam Spillway Rehabilitation Project
For the installation of temporary cofferdams our client requested to design and manufacture a portal frame which could install and remove 40T cofferdam parts and move them from one sluice gate to another.
Hebetec designed a portal frame suitable for use on top of the existing dam. Strandjacks of 40T and 70T are used for lifting, jacks are used to slide the portal frame to other positions. The complete portal frame can be operated from one control station. The project started in 2020 with the portal crane active from January 2021. It is expected to finalize in 2025.
The unique challenges include the fit on the curved dam layout as well as designing a structure with easy of transporting and assembling on site.
As there is a considerable long down time between the lifting of the cofferdam parts, the solution was chosen to use a sliding system for skidding and a strandjack system for lifting. These systems require minimal maintenance during standby compared to wheels and winches.
The provision of strandjacks and skidding system proved to be a cost effective solution.
Facts & Downloads
| Year of construction | 2021 |
| Length | 26m |
| Width | 16m |
| Height | 27m |
| Capacity | 40T |
| Skidding system | Teflon on Steel |
| Lifting jacks HA-70: | 1 |
| Lifting jacks HA-40: | 2 |
| Hydraulic pumps PA-4-8 II: | 1 |
| Hydraulic pushing jacks: | 2 |
