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Union Railroad Company: Serving Pittsburgh's Steel Mills

Published: July 25, 2024

By: Adam Burns

The Union Railroad Company, headquartered in Pennsylvania, is a historically significant shortline that has been instrumental in supporting the region's industrial operations for over a century.

Established in 1896, the Union Railroad primarily serves the greater Pittsburgh area, focusing on the transportation of raw materials and finished products for heavy industries, particularly steel manufacturing.

The company is owned by Transtar, Inc., a subsidiary of Fortress Transportation and Infrastructure Investors, following its acquisition from U.S. Steel in 2021.

The railroad covers approximately 200 total miles (including all yards and sidings), linking critical industrial sites such as mills, factories, and warehouses. Its network runs through key locations including Braddock, Clairton, McKeesport, and Duquesne.

One of the defining characteristics of the Union Railroad is its specialization in the transport of raw materials like coal, coke, iron ore, and limestone, as well as finished steel products.

This specialization has allowed the railroad to maintain a steady business for more than a century despite fluctuations in the broader economy.

The railroad's infrastructure includes extensive yards, such as the large North Bessemer Yard, and multiple sidings and spurs, facilitating the efficient shunting and staging of railcars.

Its primary customers currently includes the three plants of the USS Mon Valley Works: the Edgar Thomson Steel Works, Irvin Works, and Clairton Works.

Union Railroad's big Baldwins were known as "Buffaloes" on the system. They were twice modified, first in the early 1960s when they were re-engined with EMD engines and GP18 hoods; then later, the short hoods were chopped during the latter 1960s. Doug Kroll photo.

History

The current Union Railroad resulted from the merger of five different railroads between 1906 and 1915.  Its heritage, and eventual creation, is thanks to Andrew Carnegie, Pittsburgh's steel tycoon who wanted direct control of the railroads serving his mills. 

Initially, URR operated from East Pittsburgh to Hays, covering a distance of 6 miles, built between 1894 and 1907.

In 1900, Carnegie formed the Bessemer and Lake Erie Railroad, taking exclusive ownership and securing a 999-year lease on Pittsburgh, Shenango and Lake Erie Railroad. This arrangement persisted even after U.S. Steel acquired Carnegie's interests in 1901.

The Union Railroad was subsequently expanded to serve multiple mills in the Mon Valley region. It managed various switching tasks within each mill, delivered raw materials arriving via interchange with Bessemer & Lake Erie, and facilitated the transfer of finished products to major regional railroads, including the Pennsylvania, Baltimore & Ohio, and Pittsburgh & Lake Erie.

Union Railroad MP15DC #31 pulls a string of gondolas past a standing coke train lead by #10 at East Pittsburgh, Pennsylvania on January 11, 2024. Doug Kroll photo.

In 1906, the B&LE leased, and subsequently sold, the segment of track between North Bessemer and East Pittsburgh to the Union Railroad.

At its zenith, the URR serviced eight major steel mills and numerous other businesses, including:

• USS Homestead
• USS Rankin
• USS Edgar Thomson
• USS Duquesne-National
• USS National Tube & Pipe
• USS Clairton
• USS Irvin rolling mill
• Grant Steel (Duquesne, PA)

The URR utilized four bridges to cross the Monongahela River:

• Port Perry Bridge
• Clairton Bridge,
• McKeesport Connecting Railroad Bridge (Riverton Bridge)
• Carrie Furnace Hot Metal Bridge (Rankin Hot Metal Bridge)

By tonnage hauled, it was one of the busiest railroads in the United States. Unlike much of the steel industry, the URR embraced modernization, exemplified by the construction of a state-of-the-art yard and dispatching center in Duquesne in the early 1950s.

However, the subsequent decline of the steel industry in the United States led to a significant reduction in the Union's operations.

Steel Mills

**U.S. Steel Homestead Works – Homestead, Pennsylvania**

Steel operations ceased in 1986, and the site was razed in the late 1980s. It was transformed into a commercial shopping area known as The Waterfront, which opened in 1999.

**U.S. Steel Carrie Furnace – Rankin, Pennsylvania**

Now part of the Rivers of Steel National Heritage Area, this historic site provides a glimpse into the region's industrial past.

**U.S. Steel Edgar Thomson Steel Works – Braddock, Pennsylvania**

Andrew Carnegie's first steel mill, completed in 1875, remains operational. It is the oldest integrated steel mill in the world, sustaining its legacy of continuous steel production.

**U.S. Steel Duquesne Works – Duquesne, Pennsylvania**

Steel operations ended in 1984, and the facility was razed in the late 1990s. The location is now home to the RIDC Park, which includes a U.S. Steel Training Hub.

**U.S. Steel Mon Valley Works – Irvin Plant – West Mifflin, Pennsylvania**

Constructed between 1937-1938, this plant remains active with rolling mills and finishing operations.

**U.S. Steel Clairton Works – Clairton, Pennsylvania**

While steel mill operations ended in 1984, the facility’s coke operation continues. It is the largest coking facility in North America, producing coke and related by-products.

**U.S. Steel National Works – McKeesport, Pennsylvania**

The original steel operations ceased in 1987. However, pipe and tube operations resumed in 2011 after the purchase of the remaining pipe mills from Camp Hill Corporation.

These facilities, each with its unique history and evolution, reflect the dynamic changes within the steel industry and the ongoing impact of U.S. Steel in Pennsylvania.

Diesel Roster

Union Railroad MP15DCs #10, #21, #25, and #19 have a loaded coke train pulling up out of the Monongahela River valley and under the George Westinghouse bridge at East Pittsburgh on January 11, 2024. Doug Kroll photo.

Current Operations

Today, the principal transportation activity involves moving iron ore from the North Bessemer interchange. Coke for the Edgar Thomson plant is received from the Clairton works and interchanged at Dexter yard.

The URR also transports slabs from Edgar Thomson to Irvin works and finished steel products (coils) from Irvin works to various interchanges. Currently, the only operational bridge for rail traffic is the Port Perry Bridge.

For internal mill services, the Edgar Thomson plant uses its own switchers to handle hot metal subs and tressel unloading.

URR crews employ EMD locomotives for general switching duties within the mill, including moving loaded ore and coke cars to staging yards, spotting and pulling the caster and slab mills, and transporting scrap and flux cars into the Basic Oxygen Process (BOP).

Following the closure of the Riverton Bridge in 2008, there is no longer a direct rail connection between the URR network and McKeesport Tubular Operations ("Camp Hill").

Switching duties at McKeesport Tubular are managed by the McKeesport Connecting Railroad (MKC), another Transtar subsidiary, using Union Railroad motive power.

The Duquesne Coal Docks remain operational, unloading scrap metal from barges for Edgar Thomson and coal barges for interchange with Norfolk Southern in the Kenny Yard.

The URR continues to serve the Mon Valley and has expanded its customer base to include Dura-Bond pipe coating at the former Duquesne Works site and General Electric in West Mifflin, handling special oversized generators.