The locomotive's design was started at the CBKPTK (Central Design Bureau of Railway Stock Industry) in Poznań.
The design was finally made in 1961 by the ZNTK Poznań (Railway Stock Repair Works).
It was powered by 75 hp diesel engine and had a mechanical transmission, driving two axles by cranks and connecting rods.

From 1965, the locomotive entered series production, with a factory designation WLs75 (WLs stood for Wąskotorowa - narrow-gauge, lokomotywa - locomotive, spalinowa - internal combustion engine, practically diesel engine).
Until 1975, 86 were built.
They were built for 750 mm gauge and 785 mm gauge.
Two locomotives were made for 900 mm gauge, for a park railway in Silesian Park.

The locomotives were only used in Poland.
It was hoped, that it would be acquired by Polish State Railways (PKP), but the railways found it too weak and were not interested.
As a result, they were manufactured for the industry, mostly sugar works, smelters, steelworks and others.
Two were used by the Polish Army.
A production was relatively low, because most buyers preferred much cheaper 50 hp 2WLs50 locomotives.
The locomotive's design was started at the CBKPTK (Central Design Bureau of Railway Stock Industry) in Poznań. The design was finally made in 1961 by the ZNTK Poznań (Railway Stock Repair Works). It was powered by 75 hp diesel engine and had a mechanical transmission, driving two axles by cranks and connecting rods. 
From 1965, the locomotive entered series production, with a factory designation WLs75 (WLs stood for Wąskotorowa - narrow-gauge, lokomotywa - locomotive, spalinowa - internal combustion engine, practically diesel engine). Until 1975, 86 were built. They were built for 750 mm gauge and 785 mm gauge. Two locomotives were made for 900 mm gauge, for a park railway in Silesian Park.
The locomotives were only used in Poland. It was hoped, that it would be acquired by Polish State Railways (PKP), but the railways found it too weak and were not interested. As a result, they were manufactured for the industry, mostly sugar works, smelters, steelworks and others. Two were used by the Polish Army. A production was relatively low, because most buyers preferred much cheaper 50 hp 2WLs50 locomotives.
WLs75