Most of the public might not recall Pittsburgh tram loop dubbed the M-LOOP.
It was located among the maze of trolley tracks that laced Pittsburgh's South Hills Junction.
This was built to allow the PCC type "T" trolleys such as #1717 seen here---to short turn back out---at South Hils Junction instead of continuing onto Downtown Pittsburgh.
This M-LOOP was built off of the tracks that carried the BROWN LINE ((ex-52 ALLENTOWN)) out onto Warrington Avenue.
Many "T" lines once ran that way including the #44-KNOXVILLE, #48-ARLINGTON and after 1969--the #53 CARRICK.
With the final withdraw of the PCC type "T" cars in 1999, such loops became redundant. As of 2026, some of the switch work is still in place for the old M-LOOP but the tight curve is gone.
This image was captured for history by Bryant Schmude (("MR CONDUCTOR")) in the mid-1980's.
AS A FOOTNOTE---On the hillside spot where Schmude stood to take this image years ago, was once the grade of the Pittsburgh & Castle Shannon Railroad. It operated from 1871 until parts were electrified in 1912 into the line now the "T".
This was a narrow gauge steam railroad upon which most of Pittsburgh's Overbrook ((Blue & Silver Lines)) "T" now operate.
The P&CS RR actually ran around a horse shoe curve to the hillside--opposite this trolley--to enter a 1000ft tunnel under Mt Washington...
