A different Blacks Ladder on 6 foot track?

I am reading "Day Walks" compiled by Wilf Hilder at http://sbw.org.au/images/Documents/Wilf%20Day%20Walks[1].pdf and was intrigued by the occasional reference to Black(s) Ladder as a way of getting from the 6 foot track to the explorers tree. For example these trips on page 30:
Given the context I don't believe this is the Blacks Ladder on the north of Radiata Plateau. But I can't work out how to decode the grid references. Anyone got any clues?
- Code: Select all
KATOOMBA - Taxi or bus - O'Sullivans Rd - Narrowneck R -
Narrowneck Trig Stn - Narrowneck Track - Dunphys Pass -
Fire Rd - Mitchells Ck - Six Foot Track - Pub Site - Blacks
Ladder (Canyon)(270.345) - Marked Tree - Katoomba.
23m.R
KATOOMBA - Taxi or bus - O'Sullivans Rd - Narrowneck
Track - Diamond Spray Falls - Red Ledge Pass (2595.3040) -
Glen Shale Mine (253.304) - Old Tramway Formation -
Dixons Rd - Six Foot Track - Black Ladder (Canyon 270.345)
- road - Convict Graves - Marked Tree - Katoomba. 10m.M
Given the context I don't believe this is the Blacks Ladder on the north of Radiata Plateau. But I can't work out how to decode the grid references. Anyone got any clues?