The Plymouth Branch
This former Reading Railroad line ran between the Reading's mainline at Oreland and their Norristown mainline at a point west of Conshohocken, in Pennsylvania. The line was abandoned in segments under Conrail.
Thanks to Chris Ruhl for contributing information.
I would like to add that the connection with the trenton cutoff was only after Conrail took over.
Also near Haws lane this line crossed under the Fort Hill Branch(Fort Washington Branch/Creshim Valley Branch). That part of that branch is currently rt 309.
The Plymouth Branch started as The Plymouth Railroad Company. It was incorporated may 15th, 1836 and built a primitive, Horse Powered Tram road from Conshohocken to Corsons in the period 1836-1840 Manly to serve some quarries and lime kilns. By the late 1840s it seems to have become mostly inactive. At some point it fell under the financial control of the Philadelphia, Germantown & Norristown Railroad (PG&N) which operated a railroad from downtown philadelphia to germantown (Septa's Chestnut Hill East Line) as well as a branch to Norristown (Septa's Norristown Line). The PG&N eventually upgraded the original Plymouth RR trackage and in 1868 -1870 extended it from Corsons to Oreland where it connected to the North Pennsylvania RR. On December 1st, 1870, the PG&N, Including the Plymouth RR, was taken over by the Philadelphia & Reading RR Via a 999 year lease. in 1879 The Reading also took over the The North Pennsylvania RR system via a long term lease. In 1892 The Reading had opened a new coal terminal in port Reading in northern NJ to serve the market area of the New York City harbor. The Reading decided to try using the Plymouth Branch as a shortcut to bypass downtown Philadelphia for coal trains bound from the coal fields to Port Reading. To facilitate these through train movements, in 1896 a new track connection was built at Oreland from the Plymouth Branch to head south on the bethlehem branch, and another new connection built at Jenkintown to head up the Bound Brook Branch towards NYC and Port Reading. However, the use of the Plymouth Branch as a through rout was a failure, due to some short but steep grades, Lack of passing sidings, a tight curve at Conshohocken, as well as some bottleneck situations elsewhere on the line. On Several occasions, the Reading studied doing a total rebuild of the Plymouth Branch To handle heavy freight trains, but ultimately gave up and instead built a low-grade fright line in 1907-1915 through North and Northeast Philadelphia for its New York Bound Freight and coal trains. Passenger services on the Plymouth Branch ended in 1935. Local companies used the branch often. Remnants till remain in oreland but much of the track has been ripped up in the 70's and 80's along the line.