TCDD DE 24000 (stylised as DE 24 000 in painted registration numbers) is a type of diesel locomotive built for operations on Turkish State Railways (TCDD) by Tülomsaş. 218 units were built between 1970 and 1984 under license from Matériel de Traction Electrique (MTE) of France. The DE 24000 formed the backbone of the dieselisation of the Turkish railways during the 1970s. It follows the hood unit road switcher design, like most Turkish mainline locomotives. DE 24 000 is the most commonly found locomotive class in Turkey (431 units produced, more than 100 in usable state).

In addition to MTE, diesel parts were supplied by Chantiers de l'Atlantique, electric parts from Jeumont-Schneider, and mechanical parts from Forges et Ateliers du Creusot, all of which later acquired by Alstom.

During the 1970s the Turkish State Railways decided to replace their 800 steam locomotives with diesel. This quite-delayed task required the delivery of more than 400 diesel units. On February 15, 1968, TCDD and MTE signed an agreement for delivery of the DE 24000 along with the delivery of the smaller DE18000. To build up domestic competence on diesel engines, TCDD decided that the production would be done by Tülomsaş of Turkey. Only Tülomsaş-built units are still operational.

Blue trains (Mavi tren) and DE 24000

Main article: Blue Train (Turkey)

This section needs expansion. You can help by adding to it. (October 2016)

Blue trains are express passenger trains with 120 km/h (75 mph) timetable speed. They originally started replacing black trains (Turkish: kara tren), which are trains pulled by black steam locomotives with tenders. All cars of the blue trains had blue livery and were pulled by blue DE24000s. They are now pulled by TCDD E68000s and have regular livery but still retain their long-distance national passenger rail network status.

Overspeeding provision

These locomotives had been used over their power and speed ratings until 2004. Delayed trains were "force-fit" into the timetable by overspeeding up to 10% over timetable speeds. This required both overspeeding the prime mover and modifying the traction motors' final drive ratios. This practice was banned after the Pamukova train derailment.