T explains that the ramp was originally used to walk horses on their way between the stables on Shan Kwong Road to the racecourse:
Down close to the race course between Wong Nei Chung Road and Yik Yam Street, there was (and still is) a ramp for the horses. Back then there was metal fences on both side but part of the fences had been removed decades ago.
Henry Ching adds:
I think the ramp was built sometime in the mid-1950s. Before that, there was a fairly long flight of steps situated about half way into the alley, which stretched across its entire width. The ramp for the horses was built on the centre section of the steps. It stopped the horses from using the lower part of Shan Kwong Road. But it relegated pedestrians to two narrow passages on each side of the ramp. That alley was convenient for residents to get to the bus and tram stops without having to walk all the way down Shan Kwong Road and back along the tramlines.