One tired old unit.

The last I ran #19 was 2002, and it pretty tuckered out then. It was abused by a previous operator, and when it was "rebuilt" in the early 1990s, it received two prime movers that were not reconditioned, just sold to the C&T as is.
I saw #15 and 19 "m.u.ed" as they crossed the Airport Road in Honolulu with a bunch of pineapple racks picked up at Pearl Harbor and was taking up to the Dole Cannery. So even back in 1966, they couldn't handle a train of any size on their own. These GE units were designed for switching, period. The #19 and the similar double-ended units the D&SNG have are not appropriate for use on mountain grades. Why? The trailing or "b" prime mover overheats and eventually the engine block develops the problems usually associated with any internal combustion motor that is always allowed to overheat. The big problem is that narrow gauge road diesels are rare, and harder to find than double-enders. There were less than a half-dozen railroads that used them in North America, and now (as far as I know) there are only two- the WP&Y and the Plaster City road in Southern California.