This is INCOFER, the government railway organization for Costa Rica. The railroads there have had a rough history over the last few decades. The banana operations have been abandoned, and the two major railroads (one on the Pacific side and another on the Atlantic side meeting in San Jose, but never offered actual through service) got hit by earthquakes, hurricanes and floods. I'm not totally sure if they are still running, but there was a tourist train plus freight (Dole containers out and steel in) at the port on one of the coasts. THe amazing thing is that since 2008 they have been slowly reopening lines around San Jose to provide commuter service! These are operated with either used Spanish FEVE DMUs, or the remaining conventional equipment complete with modern day advertising wraps. There is an active railfan group there and you will find regular postings on YouTube (search for INCOFER). There is quit a bit of derelict equipment, but they slowly are repainting the operable engines and repairing some of the wrecked engines.
For narrow gauge diesels, this is almost an operating museum. All but one of the operating engines are GE, pretty much as built.
There is one 1940s 45 ton siderod supposedly bought used from the US and converted to 42" gauge.
The 30 class are 52 tons built 1955-1957 for Costa Rica Northern that replaced steam - the other side of the country had been electrified years before (all electrification is gone). Think SP#1 - except two feet longer, a turbocharged engine for 500/450 hp, dynamic brakes, cab forward - all unique to Costa Rica. I thnk there are at least three operable, not bad for 60 years old!
The 50 class are GE U6B built 1966/1971.
The 75 class are U10B built 1979.
The 80 class are U11B built 1979 - this model is unique to Costa Rica.
Dan