Sic transit Overbrook
Approaching Castle Shannon: Abandoned Overbrook tracks, Spring 2000. Stage II should bring LRVs to this ancient right-of-way --Roger DuPuis photo.
The story of Pittsburgh's Overbrook trolley line is as tortuous and precarious as its hillside right-of-way. Viewed by some as a lost cause when it was suspended in 1993, reconstruction of the line was underway in 2000.
Rail service through the Saw Mill Run Valley along this historic right-of-way began in the 1870s with the Pittsburgh and Castle Shannon Railroad. The P&CSRR was a narrow gauge, single track steam line. Its lifeblood was freight--mainly coal--but trains also carried passengers between 14 stations along the route.
Despite its name, the line's trains did not carry passengers straight through to the Golden Triangle. Trains brought passengers to Warrington Avenue, from which point two incline rides were necessary to reach river level at Carson Street. Passengers first rode up the back side of Mt. Washington on one incline, then changed to another for the ride down the front of Mt. Washington to Carson Street. From there, most riders probably finished their trip into town on city streetcars.
The latter incline--known as the Castle Shannon Incline--operated until 1964 under Pittsburgh Railways ownership. Its large cars accommodated passengers and automobiles, and postcards proudly, though questionably, proclaimed it the only incline in the world with a curve. Meanwhile, coal reached the city via a coal tunnel connected to an incline down to Carson Street.
Pittsburgh Railways leased the P&CSRR (except for the coal tunnel and its incline) from the Pittsburgh Coal Co. in 1905. PRCo. obviously had other plans for this route, and began planning for its electrification. In 1909, Pittsburgh Railways' Charleroi and Washington interurbans began running over the right of way, which had been equipped with dual gauge track to accommodate broad gauge PRCo. cars and narrow gauge coal trains. Previously, the interurbans had reached town by way of the increasingly congested Mount Lebanon route.
Coal trains were restricted to night operation after interurban service began, and were dropped altogether in 1912. Despite many changes over the years, including the addition of a second track over a significant part of the route, the ghost of the old narrow gauge operation could be seen in the form of narrow gauge tracks retained as guard rails at various points along the line. Moreover, engineers surveying the route for Stage II reconstruction in the late 1990s discovered ancient mine shafts under the right-of-way, which were a contributing cause of land subsidence and instability.
Over its long history, the new line would carry interurbans and local routes. In addition to the two interurbans, the tracks have historically been served by routes 35, 36, and 37 and their renumbered LRT-era counterparts. In addition, an short connection west from Overbrook linked up with the tracks of Route 39 Brookline. This connection was built in conjunction with the initial electrification project, and a loop service via Brookline was operated for a few years.
This corridor has commonly been called the Overbrook line, after the section of Pittsburgh through which it runs. So when one hears talk of the "Overbrook line" (on this website and elsewhere), this refers not to a single operating route, but to the tracks between South Hills Junction and Castle Shannon which carried multiple routes, as noted. Only route 37 Shannon formally used the name (a.k.a. Shannon-Overbrook), while PCCs using the tracks in later years carried the legend "via Overbrook" on destination signs.
From downtown, Overbrook-bound cars crossed the Monongahela River on the Smithfield Street Bridge, rattled across Carson Street, and entered the 3500' Mount Washington Tunnel. Both ends of the tunnel opened onto some of the most fascinating real estate in the railfan universe.
At the tunnel's base was the intersection of Carson and Smithfield Streets. At one time this intersection hosted 12 trolley lines. Trains of the B&O and PRR ran along a right-of-way parallel to Carson Street along the base of Mount Washington, while the Pittsburgh & Lake Erie's imposing station was situated across Carson Street on the north west corner of the intersection. Rising above it all was the Monongahela Incline--inclines until 1935, when the separate freight incline beside the passenger incline was closed.
At the top of the tunnel was the famed South Hills Junction. At this point, eight different carlines fanned out in four directions. The junction also was home to the tunnel carhouse complex and its distinctive administration building. At this location, cars running via Overbrook branched off to the southwest, immediately beginning their ascent to the hillside right of way.
South of the junction, the line encountered highly steep terrain. Cars passed over four single track sections with passing sidings, bridges and trestles. After hurtling across the long trestle high above Saw Mill Run Boulevard in the valley, the line returned to double tracks. The high- speed right of way followed the old railroad line south and east to Castle Shannon Boro, where it connected with the former interurban tracks running south from Mt. Lebanon, latterly served by route 38A. Until 1932, PRCo. operated an interurban carhouse here, using rebuilt P&CSRR structures. Route 37 turned back at Castle Shannon, while the interurbans and routes 35 and 36 continued towards points south.
The interurbans were discontinued in 1953, as noted elsewhere, leaving Overbrook to be served by local routes 35-37. These were renumbered in the 47 series as part of the new LRT system, when a new route was added, 47S South Hills Village via Overbrook. All of these routes were served by PCCs, as the line could not accommodate the new heavy, articulated LRVs. Instead, the Stage I LRT system ran between downtown and South Hills Village via the rebuilt Mt. Lebanon Beechview route.
The Shannon-Overbrook, Library and Drake lines were retained as conventional trolley routes. While some remedial work was done, time and the dwindling PCC fleet took their toll. In 1988, 36 aging PCCs were placed in dead storage following inspections which revealed serious deterioration of brakes and other components in many of the cars. PAT simply could not afford put this many cars through its PCC heavy rebuild program, which had proved considerably more expensive than originally predicted. With so many cars out of service, PAT found itself unable to hold down schedules on the Overbrook routes.
PAT was not able to rebuild Overbrook for LRT operation at that time, but concluded that the outer end of the Library line could conceivably accommodate LRVs with some fairly minor upgrades--namely widening the line's narrow track centres. Obviously the big cars could not run through Overbrook, so route 47L Library via Overbrook was replaced by new route 42L Library via Beechview in 1988. Intended as a remedial solution until Overbrook could be upgraded, operation of route 42L continues in 2000, and will remain in effect until Library cars can return to the rebuilt Overbrook tracks circa 2004.
On June 6, 1993, the remaining Overbrook rail services were suspended due to deteriorating track, structures and power supply. PAT was busy just then rebuilding the Mount Washington transit tunnel, an important project which started the same day. The system still didn't have the money to embark on its Stage II LRT plan, under which Overbrook would tentatively be rebuilt. Rail routes 47 Castle Shannon via Overbrook and 47S South Hills Village via Overbrook were suspended, replaced by Shannon-Overbrook buses between Castle Shannon and Downtown Pittsburgh. The outer end of route 47D Drake survived as a shuttle between Drake Loop and Castle Shannon, where through passengers transferred to and from LRVs or buses to complete their journeys.