As owner’s engineer, we provided design, tender preparation and evaluation, contract management, construction monitoring, client liaison and technical support.
Key facts
- At the start of our involvement, the new Gaborone central business district already had demarcated plots and some basic services, such as water, sewage and roads.
- Electricity to the district was required for the developers to be able to start constructing buildings.
- The district land stretches across approximately 1.5sq km.
- Our scope of services covered the design, installation and commissioning of single core 300sq mm and 240sq mm and three-core 11kV power and fibre-optic cables.
Challenges
- The cable routes to be selected constituted various possible permutations in the plethora of plots, streets and other services.
- The cable routes to connect the main substations intersected a major railway line and major road crossings. Installation works had to be performed with minimal disruptions to the district’s traffic.
- There was the threat of damaging other services previously installed.
Solutions
- We had to determine the optimum cable routes that covered all the plots.
- Sleeves were put under the road/railway and the cables were fed through to the other side on all road and rail crossings using thrust boring techniques.
- Close coordination with other service providers was essential and manual digging was implemented where there was danger of damaging other services when excavating cable trenches.
Value and benefits
- Our use of spare cable ducts on rail and road crossing points allowed for future additions and replacement of cables with minimum disruption to traffic in the district.
- Hand digging saved money by not damaging and disrupting the services already in place.