NJ Transit "NJDOT" Heritage GP40PH-2 4101

Published: April 7, 2026

The NJ Transit GP40PH-2 No. 4101 is one of the most historically significant locomotives in the agency’s fleet, representing more than five decades of continuous evolution in New Jersey commuter rail service. Today, it serves not only as an operational locomotive but also as a rolling tribute to the New Jersey Department of Transportation (NJDOT)—a critical predecessor to NJ Transit. The unit, originally of Jersey Central heritage as a GP40P, wears NJDOT's circa-1978 "Bluebird" livery of dark blue with a grey band around carbody and red trim.

An NJ Transit publicity photo featuring GP40PH-2 #4101 following its unveiling in October, 2023.

Origins: Built for the Central Railroad of New Jersey

4101 traces its lineage to October 1968, when it was constructed by Electro-Motive as Central Railroad of New Jersey (CNJ) No. 3672. It was part of a 13-unit order of GP40P passenger locomotives, funded by NJDOT to modernize commuter operations in the state. By that time the railroad was in serious financial straits and could not afford new equipment although most states continued to mandate the private freight railroads provide commuter services (which were a money-losing venture)

At the time, the GP40P, and other variants like the SDP40 and SDP35, were among the earliest examples of freight-derived diesel units adapted for passenger service, equipped with steam generators to provide heat to passenger cars. They primarily operated on CNJ commuter routes such as the Raritan Valley Line and the North Jersey Coast Line.

NJDOT and the Transitional Era

By the mid-1970s, New Jersey’s commuter railroads were struggling financially. In 1976, NJDOT assumed responsibility for commuter rail services, contracting operations to Conrail. During this period, locomotives like No. 3672 were repainted into NJDOT’s distinctive “Bluebird” scheme—a blue, silver, and red livery that symbolized a new era of state-supported rail service. This transitional phase laid the groundwork for the creation of NJ Transit in 1983, which consolidated and modernized commuter operations across the state.

Rebuilding into a GP40PH-2

In the early 1990s, NJ Transit undertook a major rebuilding program for its aging GP40P fleet. No. 3672 was rebuilt by Conrail into a GP40PH-2, receiving:

Head-end power (HEP) capability for modern passenger cars
Upgraded electrical systems
Improved reliability and performance

Following rebuilding, the locomotive was renumbered 4101 and continued in regular commuter service.

Remarkably, 4101 remains one of only three original ex-CNJ GP40P-derived locomotives still in active service, alongside 4100 and 4109.

The NJDOT “Bluebird” Heritage Scheme

In October 2022, NJ Transit unveiled No. 4101 as part of its growing Heritage Fleet, repainting it into the NJDOT-era “Bluebird” scheme.

This livery honors:

NJDOT’s stewardship of commuter rail (1976–1983)
The transition from private railroads to public transportation
The role of Conrail in operating early state-supported services

The locomotive became the fourth heritage unit in NJ Transit’s commemorative series, joining others that celebrate legacy railroads such as CNJ, Erie, and Conrail.

Today, 4101 operates in regular revenue service, allowing passengers to experience a living piece of New Jersey rail history.

General Specifications

Specification	Details
Builder	Electro-Motive Division (EMD)
Build Date	October 1968 (as CNJ 3672)
Rebuild	1991–1993 (Conrail, GP40PH-2)
Wheel Arrangement	B-B (four axles)
Engine	EMD 16-645E3 V16 diesel
Horsepower	3,000 hp
Power Type	Diesel-electric
Length	Approximately 59 ft
Maximum Speed	Up to ~100 mph (passenger gearing)
Head-End Power	Yes (for passenger cars)
Original Owner	Central Railroad of New Jersey (CNJ)
Current Owner	NJ Transit
Notable Livery	NJDOT “Bluebird” Heritage Scheme (2022)

Legacy

NJ Transit No. 4101 stands as a rare survivor of a transformative period in American commuter railroading. From its beginnings under the CNJ, through NJDOT’s stewardship, to its modern role under NJ Transit, the locomotive embodies the evolution of publicly supported passenger rail in New Jersey.

Its 2022 repaint into the NJDOT “Bluebird” scheme ensures that this history is not only preserved—but actively seen by thousands of commuters each day. Few locomotives in the United States can claim such a continuous and meaningful connection to the development of modern transit systems.

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