Tobacco Tunnel

Project Overview: 30Ha Straight tunnel with a 42×49.5m Grading and Storage Shed.


  • This is the first stage of a 60Ha tunnel and utilizes only one heatsource. The heatsource consists of a 3.3m kettle with 3 banks of 3.3m x 1.8m of radiators. The furnace is stoked by a 300lb per hour stoker on an automated thermostat monitoring air and water temperature. There are 2x 3Hp fans and 1x2Hp fan blowing a maximum of 55 000cfm of air through the radiators into the tunnel.
  • The tunnel is 140m long and sloped downwards by 1.5m over the length of the tunnel. This slope decreases the labour required to push the trollies through the tunnel. A straight tunnel also has the advantage that the air does not have to turn any corners, so the airflow is more uniform throughout the tunnel. The temperature, humidity and wet bulb temperature are fully automated and controlled on a single board.
  • On an 8-day cure (1 day in the green-bay, 7 days in the tunnel), the tunnel is capable of curing 18 trolleys with 180 clips of tobacco per day. The tobacco is conditioned in the shed with an automated misting system.