No. 878 is a 350°F gas-heated tunnel oven from Grieve, currently used for drying water from aluminum parts hung on a monorail pass-through conveyor. The workload passes through a 24-in.-long insulated, unheated entrance vestibule, a 144-in.-long insulated heat zone with recirculated airflow and a 24-in.-long insulated, unheated exit vestibule.