Union Railroad: History, Route, Roster

Published: July 25, 2024

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

Model	Builder	Road Number	Serial Number	Completion Date	Heritage/Notes
SW1500	EMD	1-5	72605-1 thru 72605-5	11/1972	-
SW1500	EMD	6-9	72673-1 thru 72673-4	9/1973	-
MP15DC	EMD	10-14	73645-1 thru 73645-5	7/1974	-
MP15DC	EMD	15-21	74667-1 thru 74667-7	6/1975-7/1975	#15 renumbered 34.
MP15DC	EMD	22-24	756070-1 thru 756070-3	3/1976	-
MP15DC	EMD	25-26	766013-1, 766013-2	12/1976	-
MP15DC	EMD	27-33	766057-1 thru 766057-7	2/77	-
SW1001	EMD	101-103	756071-1 thru 756071-3	3/1976	-
65-Ton	Whit 65DE-19a	401	60347	11/43	Ex-USA 7977 (acq 12/46); to Cliff Quarries
		402	60433	3/44	To Chicago Gravel 504; ex-USA 1350 < USA 8427 (acq 12/46); to Cliff Quarries
		403	60407	3/44	To Armco National Supply Div 37; ex-USA 1311 < USA 8401 (acq 2/47)
		404	60427	4/44	To Marble Cliff Quarries 404 > Beaufort & Morehead 65; ex-USA 1347 < USA 8421 (acq 12/46); to Armco National Supply Div 37
		405	60377	2/44	To Chicago Gravel 505; ex-USA 1306 < USA 8136 (acq 12/46); to Armco National Supply Div 37
		406	60361	1/44	To Hagerstown & Frederick 1; ex-USA 8120 (acq 3/467)
		407	60346	11/43	To American Aggregates 407 r# 11587; ex-USA 7976 (acq 3/46)
		408	60350	11/43	To Johnstown & Stoney Creek 1 r# 3 > NYCTA 20000 r# 9; ex-USA 7980 (acq 12/46)
		409	60363	1/44	To Hagerstown & Frederick 2 > American Aggregates 12335 > Blue Rock Transportation 12335; ex-USA 8122 (acq 3/47)
		410	60442	15/44	To Etna & Montrose 410 > Deitch Iron & Metal 4105; ex-USA 1353 ex-8436 12/46
S1	Alco	451, 452	75234, 75349	6/47	451 To Mears Coal (same #) and 452 to C & K Coal 452 > RLCX 709
		453-454	75351, 75352	6/47	453 to BEDT and 21 NYCH 21 and 454 To Glen Irvan Coal > Trojan Coal Co
SW1	EMD	455 - 468	7502-15	6-8/1949	455 to United States Steel - Clairton Works #? 456 to LRS 114 458 to LRS 115, to NCYR 115 460 to United States Sugar Co 148 462 to JSC 462, to TCKR 462 463 to LRS 116 464 to LRS 119, to NCYR 119 HS 119 465 to LRS 117 466 to MVRY 466 467 to MVRY 467 468 to LRS 118
		469 - 470	8531, 8532	2/1950	469 to JSC 469 and 470 to LRS 120
		471 - 476	7/1950	10901-10905	-
VO1000 (Baldwin)	500 - 501	62404-05	9/1940	To PBR 329 (2) and PBR 357
VO1000 (Baldwin)	502 - 505	64203-06	7-8/1941	502 To Universal Iron & Steel Co 502
				504 To Track & Maintainance Equipmernt Co 504
				505 To PBR 353
S2 (Alco)	506	69548	8/41	To Tube City Iron & Metal
S2 (Alco)	507	69549	8/41	Birmingham Rail & Locomotive > Weirton Steel {parts supply}, scrapped
S2 (Alco)	508	69550	9/41	To Lenawee County 2
S2 (Alco)	509	69551	9/41	To USS Thomson slug 115 r# 5-M
S2 (Alco)	510	69552	9/41	To Weirton Steel Co. 222
S2 (Alco)	511	69553	9/41	Birmingham Rail & Locomotive > Weirton Steel {parts supply}, scrapped
S2 (Alco)	512 & 513	69908, 69909	7/42	512 to Weirton Steel Co. 222
S2 (Alco)	512 & 513	69908, 69909	7/42
S2 (Alco)	514 - 518	70209-70213	7, 12/1943	515 To Tube City Iron & Metal > Precision National, scrapped
				516 To J&L/MCRR 137 > J&L/MVRY 137
				517 To Tube City Iron & Metal > Precision National, scrapped
				518 To Western Ohio 101

S2 (Alco)	519 - 527	73623-73631	8/1945	519 to Birmingham Southern 519 to USS/Universal Atlas Cement 519> Birmingham Rail & Locomotive, scrapped
				520 to USS Thomson 117 (2nd) to USS Duquesne Works 117
				521 to Naporano Iron & Metal, scrapped
				522 to Tube City Iron & Metal > Precision National
				523 to Lake Terminal slug S-2 to EJ&E T-2 > Transtar/Gary Western T-2
				524 to USS Thomson 110
				525 to Birmingham Southern 525 > US Steel Gary 77:2



S2 (Alco)	528-530	73638--73660	xx/1945?	528 to Thomson slug 109 r# 1-M
				529 to Thomson 119
				530 to Michigan Elevator Exchange 530 > Mid-States Grain Terminal 530 (same) > Mid-States Grain Terminal 530 > Countrymark Co-Op 530 (same), scrapped
S4 (Alco)	531-535	75667-75671	4-5/1951	531 to Lake Terminal slug S-1 > EJ&E T-1
				533 to Tube City Iron & Metal
				534 to US Steel Slug 114:2 - "Edgar Thomson Works" > US Steel 4-M - "Edgar Thomson Works"
				535 to Birmingham Southern 535 > US Steel Gary 61 (2nd)

S4 (Alco)	536	78714	4/1951	To USS Thomson 118 to slug 113 r# 3-M
S4 (Alco)	537	78715	4/1951	To USS Thomson 119
NW2 (EMD)	538	5268	3/1948	Ex-Y&N 288 < nee LT 1014
NW2 (EMD)	539 (2nd)	4794	4/1947	Ex-Y&N 287 < B&LE < NB 1001 < nee LT 1001
NW2	EMD	540 (2nd)	4796	4/1947	Ex-Y&N 286 < B&LE 286 < NB 1002 < nee LT 1002
541-549	EMD	7521-7529	4-5/1949		541 To LRS 123 542 To NCRY 124, to LRS 123, to CPRX 124 545 To LRS 125 546 To LRS 126
550-555	EMD	8534-8539	10-11/1949	To TCKR 550
556-560	EMD	7516-20	8-9/1948	Ex-Union 536-450
561-562	EMD	4798-90	8-9/1948	Ex-LT 1003-1004
SW9	EMD	563-565	17871, 76-77	3/1953	Ex-DMIR 12 and 17-18
SW9	EMD	566-568	17879-81	3/1953	Ex-DMIR 20-22
SW9	EMD	569-570	17872, 17874	3/1953	Ex-DMIR 13, 15
SW9	EMD	571(2nd)-572 (2nd)	17875, 17878	3/1953	Ex-DMIR 16, 19
SW7	EMD	571 (1st)-572 (1st)	10898-10899	11/1950	(see TR5A & TR5B notes at end of roster)
SW7	EMD	573 (1st)-574 (1st)	10235-36	11/1950	(see TR5A & TR5B notes at end of roster)
SW9	EMD	573(2nd)	17882	3/1953	Ex-DMIR 23
NW2	EMD	574(2nd)	6681	11/1948	Ex-B&O 9550 (558)
SW9	EMD	575-576	13953-54	2/1951	(see TR5A & TR5B notes at end of roster)
SW9	EMD	577-578	15064-65	10/1951	(see TR5A & TR5B notes at end of roster)
NW2	EMD	579	5959	11/1951	(see TR5A & TR5B notes at end of roster)
SW9	EMD	580 & 581	15960, 15961	2/1952	581 to Westinghouse-General Electric 8301 > CYXX 2112
SW9	EMD	582 & 583	15962, 15963	2/1952	--
SW9	EMD	584-588	15964-68	2/1952	(see TR5A & TR5B notes at end of roster)
SW1200	EMD	584 & 585 (2nd)	20090, 20091	12/1954	To URR 704D & 704; ex-FEC 231 & 232
SW1200	EMD	586 (2nd)-587 (2nd)	20089, 20094	12/1954	Ex-NSS 1201 & 1205, nee FEC 230 & 235
SW9	EMD	588 (2nd)	17810	4/1953	Ex-Y&N 302, nee UP 1830
RS2	Alco	601-607	75694-75700	3-4/1948	601 To PSL 702, to IC 702 602 To PSL 703, to IC 703 603 To PCCX 101 604 To ALS 46-1046 605 To ALS 47-1049 606 To ALS 48-1050 607 To ALS 52-1051 > Scotis Coal Co 1055
RS2	Alco	608-610	76828-76830	5-6/1949	608 To PCN 7 609 To ALS 49-1054 610 To ALS 53-1055
RS2	Alco	611 & 612	76971-76972	6/1949	To ALS 54/1057 and ALS 51/105
DRS66-1500	BLW	613-614	74220-21	2/1949	Reblt 6/60 & 10/63 respectively, (EMD 8568-1, 8575-1)
DRS66-1500	BLW	615-616	74215-16	2/1949	Reblt 4/62 & 11/61 respectively, (EMD 8572-1, 8569-3)
DRS66-1500	BLW	617-618	74217-18	2/1949	Reblt 10/59 & 3/65 respectively, (EMD 8561-1, 8578-2)
DRS66-1500	BLW	619	74219	2/1949	Reblt 7/62, (EMD 8574-1)
DRS66-1500	BLW	620-624	74696-700	10/1949	Reblt (EMD 8576-1, 8573-1, 8578-1, 8578-3, & 8568-2)
AS616	BLH	625-627	75165-67	/1951	-
SD9	EMD	630-631	23104 & 23108	2/1957	Ex-DMIR 116 & 120
SD9	EMD	632-633	23113 & 23116	2-3/1957	Ex-DMIR 125 & 128
TR5	EMD	701 & 702	8544, 8545	3/1951	--
TR5	EMD	703	--	1/1951	Ex-URR 572
TR5	EMD	704-708	--	-	(see TR5A & TR5B notes at end of roster)
TR5B	EMD	701C & 702C	8546 & 8547	3/1951	(see TR5A & TR5B notes at end of roster)
TR5B	EMD	703C-704C	14786, 10787	10/1951	(see TR5A & TR5B notes at end of roster)
TR5B	EMD	705C-708C	(see note)	10/1951	(see TR5A & TR5B notes at end of roster)
SD9	EMD	830	21732	4/1956	Ex-BLE 830 < nee DMIR 830

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.