Designing pit emptying technologies: combining lessons from the field with systems thinking

The ideal pit emptying machine has been envisioned to be safe, hygienic, and economical, while being mobile and lightweight, allowing access to pits located away from main roads. The machine should be robust, should be amenable to easy operation by a few personnel, and can be maintained using local expertise and supplies. Using the insights from a recent workshop and our own field experience, we discuss the challenges of designing such a machine, and broaden the discussion to include the entire system of pit emptying, collection, and transport. We classify pit emptying technologies according to the type of pit (e.g., wet pits with little trash, wet pits with lots of trash, and dry pits with lots of trash), and argue that designing technologies accordingly should be the focus in the future. A systems approach that includes transport optimisation, sustainability of small businesses, and operator safety and training is advocated.