Iran Heavy Diesel Manufacturing Company (DESA), is an Iranian company which is a manufacturer of heavy diesel engines from 200 to 3500 kW for railway, marine and power generation purposes.

The Iran Heavy Diesel Engine Mfg Co. (DESA) company was established in 1991 in Amol with the aim of developing industrial production of diesel engines; a factory of over 10,000m2 was constructed on a 80ha site, with facilities for quality testing and research and design.

[2] The company produces diesel generators for permanent and emergency electricity supply.

[3][4] The company is also assembling 16V 4000 MTU type diesel engines[1] for a contract for 150 IranRunner locomotives for passenger trains to be manufactured by Siemens and the MLC (Mapna Locomotive Engineering and Manufacturing Company).

The first 30 units will be supplied by Siemens, the remaining 120 will be primarily manufactured domestically capacities and expertise over six years.