Meet our Industrial EngineerOctober 10, 2018
Nkosinathi MthethwaJanuary 16, 2019
Luke Mafuma, an engineer in MBB’s Grahamstown office, assisted with MBB Nelspruit’s installation of the Malawi Nchalo (Illovo) conversion of 460 ha from sprinkler to drip irrigation as part of their yield recovery programme. His role as the Project Manager and Resident Engineer saw him spend about four months on the estate, staying on site 28 days at a time.Many challenges were experienced, similar to those of the first phase, which soon became known as “lessons not learnt.” These challenges included:
- Difficulty in meeting project deadlines, resulting in the risk of cane seed being too old to plant.
- Delayed land preparation resulting in costly power harrowing in order to achieve acceptable seed beds.
- Onerous procurement practices. Most purchase requisitions needed at least 5 signatures for approval. Many requisitions had to be referred to headquarters for approval, even for goods purchased locally.
- Late delivery of steel fittings and motor control panels thus having to resort to the use of temporary fittings.
- Contentious quality control, with the contractor not heeding instructions.
- Limited dedicated transport for project workers resulting in reduced productivity and delays.
- Technical constraints included:
- Shallow groundwater levels resulting in collapsing trenches, as well as requiring dewatering over extended periods before work could recommence.
- Extremely high sediment load in the water which clogged the filters, requiring excessive backwashing. Alternative settling methods were then planned.
Ground water in the pipe trenches
Clogged filters opened for cleaning
On a personal level, the conditions for work were extreme. The heat of summer months in Malawi is not to be taken lightly, seriously limiting productivity. It was not unknown for dehydration or skin rash due to exposure being experienced.
The results of this work, however, are enduring. The well-installed and operating drip irrigation of sugarcane on this estate is likely to boost yields significantly. The water saving technology of drip irrigation is also helping reduce the water footprint, something that plays strongly into the industry’s efforts towards climate change resilience strategies. The job well done will enhance sustainability and may become the standard in irrigation technology in the industry.
Skin rash due to sun exposure and heat
Filter banks with valve clusters