Yes, Johnson Avenue was south of Jamaica Station and fed the Dunton Electric Car Shops which was in the same location. It had a yardmaster's cabin at the switch which was just west of the Sutphin Boulevard overpass, south of the secondary tracks.
The yard tracks had a significant grade to them which made the place challenging at times when equipment had brakes cut out. It was built as a freight team yard and lead to the Shops.
The yard was used for shop equipment that was destined to go into Dunton Shops. There were several significant accidents in the yard. An old style double decker got away down the hill and wound up sticking out over the retaining wall of the Van Wyck Expressway, as did an M-1. And yes, a car inspector was crushed by a self-charging M-1 in the late 1980's.
Dunton Shops, which were horribly outdated and went back to 1913 were closed in the 90's and demolished to make way for the Airtrain project. They were replaced by the Hillside Shop.
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The Long Island Tool
"... overzealously discharges his duties;
...a "tool" of the administration"