Electrification of the New York, New Haven, and Hartford Railroad
Encyclopedia
The New York, New Haven, and Harford railroad pioneered electrification
of main line railroads using high-voltage, alternating current, single-phase overhead catenary
. It electrified its mainline between Stamford, CT and Woodlawn, NY
in 1907, and extended the electrification to New Haven, CT in 1914. While single-phase AC railroad electrification has become commonplace, the New Haven's system was unprecedented at the time of construction. The significance of this electrification was recognized in 1982 by its designation as a National Historic Engineering Landmark by the ASME.
The third rail system resulted, not unsurprisingly, in a number of accidents. It also resulted in a decree from the Connecticut supreme court on June 13, 1906 forbidding the use of third rail electrification within the state. The New Haven was forced by this decision to design their main line electrification system using overhead catenary.
Several different systems combinations of voltage and frequency were considered in the initial design. Due to the relatively large distances involved, transmission at high voltages using alternate current was recognized as being unavoidable. An architecture similar to commercial DC utilities and urban railroads was considered using high voltage transmission lines, rotary converters, and overhead DC catenary. The studies of the time assumed an electrical efficiency of only 75% for this architecture.
The highest voltage for which generators could be reliably designed at this time was about 22 kV. An intermediate design was considered using 22 kV transmission lines, substations to reduce catenary voltage to between 3 and 6 kV, and transformers on the engines to the 560 V required by the traction motors. The railroad realized that it could save significant capital cost if the intermediate substitution were omitted and locomotives received line voltage at around 11 kV.
The triangular cross-section of catenary used in the original electrification was only repeated by one other railway - the London, Brighton and South Coast Railway used a similar triangular catenary from 1909 until 1929. The New Haven's 1914 extensions dispensed with the triangular catenary design.
Catenary support spacing was set at 300 feet (91.4 m). This was based on keeping the straight line deviation from center of track to within 8.5 inches (215.9 mm) with a curve radius of 3 degree, which was the tightest curve between the original system's termini at Woodlawn and Stamford.
were designed to supply single-phase power directly to the catenary. They were also required to supply three-phase power both to the New Haven itself for use along the lines, and to the New York Central's Port Morris
generating station to compensate the NYC for the power consumed by New Haven trains on the NYC's third-rail supplied line to Grand Central. The Cos Cob generators were three-phase machines, but wired to supply both three phase and single phase power simultaneously.
The second was that the system's geographic growth and the evolving state of electrical technology created a need for higher transmission voltages. The railroad could have simply raised the operating voltage of the entire system, however this would have required all the catenary insulators to be upgraded to withstand a higher potential, and replacement of all the locomotive high voltage equipment. And while higher transmission voltages had become common in the seven years since the initial electrification, generators were still limited by economics to a maximum output voltage of around 11 kV.
The solution decided upon by the railroad, after several years of study, was a balanced autotransformer
system.
Remarkably, the railroad changed transmission system architectures within four hours, although preliminary work had taken the preceding 18 months. On Sunday, January 25, 1914, the railroad shutdown the entire power system at 2 am. Gangs of workers throughout the system reconfigured the transmission lines over the next 70 minutes. System startup was commenced and by 5:30 am, electric trains were running over the new, autotransformer supplied system.
to the New York Connecting Railroad
upon the line's construction. The system of electrification was an extension of the New Haven's revised 11/22 kV autotransformer architecture. The original electrification extended from the New Haven's main line, across the Hell Gate Bridge, to the Bay Ridge yard. The line south of Bowery Bay Junction was de-electrified in the 1950s. The line between New Rochelle and the Harold Avenue Interlocking was transferred to Amtrak
in 1976 upon dissolution of Penn Central. The electrification system continued to be controlled as a portion of the ex-New Haven system until the 1987 conversion to 60 Hz operation.
When the New Haven main line was converted by Metro North to 60 Hz operation, the Amtrak Hell Gate line was also converted, but as an isolated system powered from the Van Nest substation. Control of the catenary system was transferred from Cos Cob to the Load Dispatcher at New York Penn Station. Although conversion occurred subsequent to the PRR-era electrification, Amtrak substation numbers 45-47 were assigned for consistency with the rest of the PRR numbering scheme.
Railway electrification system
A railway electrification system supplies electrical energy to railway locomotives and multiple units as well as trams so that they can operate without having an on-board prime mover. There are several different electrification systems in use throughout the world...
of main line railroads using high-voltage, alternating current, single-phase overhead catenary
Overhead lines
Overhead lines or overhead wires are used to transmit electrical energy to trams, trolleybuses or trains at a distance from the energy supply point...
. It electrified its mainline between Stamford, CT and Woodlawn, NY
Woodlawn (Metro-North station)
The Woodlawn Metro-North Railroad station serves the residents of the Woodlawn section of The Bronx via the Harlem Line. It is 11.8 miles from Grand Central Terminal and is located on East 233rd Street, three blocks from the 233rd Street station on the IRT White Plains Road Line of the New York...
in 1907, and extended the electrification to New Haven, CT in 1914. While single-phase AC railroad electrification has become commonplace, the New Haven's system was unprecedented at the time of construction. The significance of this electrification was recognized in 1982 by its designation as a National Historic Engineering Landmark by the ASME.
Initial Electrification Experiments
The New York, New Haven, and Hartford tried several experiments with low-voltage DC electrification in the decade preceding their main line overhead electrification. These included:- 1895 electrification of 11 km (6.8 mi) of line between Nantasket JunctionNantasket Junction (MBTA station)Nantasket Junction Station is a rail station on the MBTA Commuter Rail system in Hingham, Massachusetts. The station, located at 190 Summer Street, is the seventh of ten along the MBTA's Greenbush Line, which provides service between Scituate and Boston. The line, which reopened on...
and Pemberton, MA using overhead copper contact wire at 600-700 Vdc. - This line was extended an additional 5.5 km (3.4 mi) to East WeymouthEast Weymouth (MBTA station)East Weymouth Station is a rail station on the MBTA Commuter Rail system in Weymouth, Massachusetts. The station, located at 1590 Commercial Street, is the fifth of ten along the MBTA's Greenbush Line, which provides service between Scituate and Boston. The line, which reopened on October 31,...
around 1896. - Third-rail electrification between Hartford, New BritainNew Britain, ConnecticutNew Britain is a city in Hartford County, Connecticut, United States. It is located approximately 9 miles southwest of Hartford. According to 2006 Census Bureau estimates, the population of the city is 71,254....
, and BerlinBerlin (Amtrak station)Berlin is a train station in Kensington, Connecticut located on the New Haven-Springfield Line. It serves both Kensington and nearby Berlin, which is why it is also known as Kensington-Berlin Amtrak Station. The station was originally built in 1900 by the New York, New Haven & Hartford Railroad,...
, a total of 20 km (12.4 mi) in 1896. This third-rail system was unique; it consisted of an inverted V cross-section rail, mounted on the cross ties between the running rails, and was totally exposed.
The third rail system resulted, not unsurprisingly, in a number of accidents. It also resulted in a decree from the Connecticut supreme court on June 13, 1906 forbidding the use of third rail electrification within the state. The New Haven was forced by this decision to design their main line electrification system using overhead catenary.
Several different systems combinations of voltage and frequency were considered in the initial design. Due to the relatively large distances involved, transmission at high voltages using alternate current was recognized as being unavoidable. An architecture similar to commercial DC utilities and urban railroads was considered using high voltage transmission lines, rotary converters, and overhead DC catenary. The studies of the time assumed an electrical efficiency of only 75% for this architecture.
The highest voltage for which generators could be reliably designed at this time was about 22 kV. An intermediate design was considered using 22 kV transmission lines, substations to reduce catenary voltage to between 3 and 6 kV, and transformers on the engines to the 560 V required by the traction motors. The railroad realized that it could save significant capital cost if the intermediate substitution were omitted and locomotives received line voltage at around 11 kV.
Original 1907 Direct-feed Architecture
The New Haven's electrification was the first of its kind; no previous railroad had practical experience operating a high voltage distribution system above a steam railroad. Many of the system's ultimate specifications were the result of educated design decisions based on the state of the electrical technology in 1907.Voltage
The designers considered several voltages for the transmission segment of the system including 3-6 kV, 11 kV, and 22 kV. Ultimately, the transmission and catenary systems were combined into a transformerless system, that utilized the same voltage from output of generator to catenary to locomotive pantograph. As 11 kV was the highest voltage that could be obtained directly from the output of the generators of 1907, 11 kV was selected as the transmission and catenary voltage of the system.Frequency
The New Haven considered two different operating frequencies for use in their electrification - 15 Hz and 25 Hz. The lower frequency of 15 Hz afforded reduced motor size, lower inductive losses, and a higher motor power factor. 25 Hz had by 1907 already become a commercial standard, and the railroad already operated a number of trolley power houses at 25 Hz and had equipped many of its shops with 25 Hz motors. Selection of 15 Hz viewed by the railroad as a 'break in gage' which would have limited the commercial value of the system. Thus the railroad selected the 25 Hz standard, even though it might have been more desirable from an engineering perspective. Note that many European railroads standardized on a 16.7 Hz traction power frequency.Catenary
The New Haven had no precedent to follow when designing their catenary system. Overhead catenary had previously been the domain of trolleys, except for a few three-phase railways in Europe. No prior experience existed with operating high-speed railways with an overhead contact system. The Catenary designed by the New Haven was a unique, relatively rigid triangular cross-section.The triangular cross-section of catenary used in the original electrification was only repeated by one other railway - the London, Brighton and South Coast Railway used a similar triangular catenary from 1909 until 1929. The New Haven's 1914 extensions dispensed with the triangular catenary design.
Catenary support spacing was set at 300 feet (91.4 m). This was based on keeping the straight line deviation from center of track to within 8.5 inches (215.9 mm) with a curve radius of 3 degree, which was the tightest curve between the original system's termini at Woodlawn and Stamford.
Generators
The generators at the Cos Cob Power StationCos Cob Power Station
Cos Cob Power Station is a historic district roughly bounded by Metro North Railroad tracks, the Mianus River and Sound Shore Drive in Greenwich, Connecticut.The Spanish Revival style station was built in 1907....
were designed to supply single-phase power directly to the catenary. They were also required to supply three-phase power both to the New Haven itself for use along the lines, and to the New York Central's Port Morris
Port Morris, Bronx
Port Morris is a neighborhood in the southwest Bronx, New York City. It is a heavily industrial neighborhood. Its boundaries are the Major Deegan Expressway and Bruckner Expressway to the north, East 149th Street to the east, the East River to the southeast, the Bronx Kill south, and the Harlem...
generating station to compensate the NYC for the power consumed by New Haven trains on the NYC's third-rail supplied line to Grand Central. The Cos Cob generators were three-phase machines, but wired to supply both three phase and single phase power simultaneously.
Revised 1914 Autotransformer Architecture
Although the railroad considered the 1907 electrification highly successful, two problems required an ultimate redesign of the transmission system. The first was electromagnetic interference in adjacent, parallel telegraph and telephone wires caused by the high currents in the traction power system.The second was that the system's geographic growth and the evolving state of electrical technology created a need for higher transmission voltages. The railroad could have simply raised the operating voltage of the entire system, however this would have required all the catenary insulators to be upgraded to withstand a higher potential, and replacement of all the locomotive high voltage equipment. And while higher transmission voltages had become common in the seven years since the initial electrification, generators were still limited by economics to a maximum output voltage of around 11 kV.
The solution decided upon by the railroad, after several years of study, was a balanced autotransformer
Autotransformer
An autotransformer is an electrical transformer with only one winding. The auto prefix refers to the single coil acting on itself rather than any automatic mechanism. In an autotransformer portions of the same winding act as both the primary and secondary. The winding has at least three taps where...
system.
Remarkably, the railroad changed transmission system architectures within four hours, although preliminary work had taken the preceding 18 months. On Sunday, January 25, 1914, the railroad shutdown the entire power system at 2 am. Gangs of workers throughout the system reconfigured the transmission lines over the next 70 minutes. System startup was commenced and by 5:30 am, electric trains were running over the new, autotransformer supplied system.
Substations
| Substation No. | Catenary Bridge No. | Name | Built | Coordinates | Comments |
|---|---|---|---|---|---|
| New Haven Line | |||||
| 1114 | Cedar Hill | ||||
| 1104 | Mill River (Section Break) | ||||
| 1060 | Cedar St. | 41.2937°N 72.9305°W | |||
| 962 | Woodmont | ||||
| 863 | Devon | ||||
| 814 | Bishop Ave | ||||
| 736 | Burr Road | ||||
| 633 | Green's Farms | ||||
| 524 | South Norwalk | ||||
| 465 | Darien | 41.0773°N 73.4686°W | |||
| 374 | Stamford | ||||
| 296 | Greenwich | ||||
| 245 | Port Chester | 41.0053°N 73.6559°W | |||
| 193 | Rye | ||||
| 126 | Mamaroneck | 40.9467°N 73.7446°W | |||
| SS22 | 72 | New Rochelle | 1914 | 40.9127°N 73.7826°W | Converted to 60 Hz c. 1986 |
| 0 | Woodlawn | ||||
| Harlem River and Port Chester Branch Harlem River and Port Chester Railroad The Harlem River and Port Chester Railroad was a branch of the New York, New Haven and Hartford Railroad, upgraded to main line status in 1917 with the completion of the New York Connecting Railroad and its Hell Gate Bridge... |
|||||
| ATK 47 | 211H | Amtrak New Rochelle | 1987 | 40.9069°N 73.7900°W | |
| SS14 | 149H | Baychester/Pelham Bridge | 1914–1987 | ||
| SS12 | 139H | Westchester/Pelham Parallel | 1914–1987 | 40.8167°N 73.8933°W | |
| ATK 46 | Amtrak Van Nest | 1987 | 40.8420°N 73.8633°W | ||
| SS8 | 84H | West Farms Junction | 1914-1987. | 40.8347°N 73.8794°W | Supplied from Sherman Creek Sherman Creek Generating Station The Sherman Creek Generating Station was a coal fired power plant constructed by the United Electric Light and Power Company. The station was located in New York City, NY on Manhattan Island at 201st Street and the Harlem River... ; later from Con Ed Hell Gate GS. The substation and adjacent passenger station have been demolished; an impound lot occupies the site. |
| SS4 | 58H | Oak Point | 1914–1987 | 40.8075°N 73.9049°W | |
| SS3 | 42H | Bungay St | 1914?-1987 | NH 3ph power supplied to NYC's Port Morris GS to compensate for NH's consumption on NYC DC lines. | |
| SS1 | 2H | Harlem River | 1914-19?? | ||
| New York, Westchester and Boston Railway New York, Westchester and Boston Railway The New York, Westchester and Boston Railway Company , known to its riders as "the Westchester" and colloquially as the "Boston-Westchester", operated as an electric commuter railroad in the Bronx and Westchester County, New York from 1912 to 1937... |
|||||
| Columbus Ave Mt Vernon | |||||
| White Plains | |||||
| New York Connecting Railroad New York Connecting Railroad The New York Connecting Railroad or NYCR is a rail line in the borough of Queens in New York City. It links New York City and Long Island by rail directly to the North American mainland. Amtrak, CSX, Canadian Pacific Railway, Providence and Worcester Railroad and New York and Atlantic Railway... |
|||||
| ATK 45 | C68 | Bowery Bay | 1918 | 40.7643°N 73.9054°W | |
| Converted to 60 Hz c. 1986. | |||||
| Long Island Railroad Bay Ridge Branch Bay Ridge Branch The Bay Ridge Branch is a rail line owned by the Long Island Rail Road and operated by the New York and Atlantic Railway in the U.S. State of New York... |
|||||
| 55 | Fresh Pond | 1927-19?? | |||
| 2 East New York (FC) | 1927-19?? | Connects the single phase to/from PT&T/LIRR's 3 phase 25 Hz. | |||
| 54 | East New York Swg. | 1927-19?? | |||
| 53 | New Lots Ave | 1927-19?? | |||
| 52 | Manhattan Beach | 1927-19?? | |||
| 51 | 4th Ave Bay Ridge | 1927-19?? | |||
Hell Gate Line
The New Haven's system was extended across the Hell Gate BridgeHell Gate Bridge
The Hell Gate Bridge or Hell's Gate Bridge is a steel through arch railroad bridge between Astoria in the borough of Queens and Randall's and Wards Islands in New York City, over a portion of the East River known...
to the New York Connecting Railroad
New York Connecting Railroad
The New York Connecting Railroad or NYCR is a rail line in the borough of Queens in New York City. It links New York City and Long Island by rail directly to the North American mainland. Amtrak, CSX, Canadian Pacific Railway, Providence and Worcester Railroad and New York and Atlantic Railway...
upon the line's construction. The system of electrification was an extension of the New Haven's revised 11/22 kV autotransformer architecture. The original electrification extended from the New Haven's main line, across the Hell Gate Bridge, to the Bay Ridge yard. The line south of Bowery Bay Junction was de-electrified in the 1950s. The line between New Rochelle and the Harold Avenue Interlocking was transferred to Amtrak
Amtrak
The National Railroad Passenger Corporation, doing business as Amtrak , is a government-owned corporation that was organized on May 1, 1971, to provide intercity passenger train service in the United States. "Amtrak" is a portmanteau of the words "America" and "track". It is headquartered at Union...
in 1976 upon dissolution of Penn Central. The electrification system continued to be controlled as a portion of the ex-New Haven system until the 1987 conversion to 60 Hz operation.
When the New Haven main line was converted by Metro North to 60 Hz operation, the Amtrak Hell Gate line was also converted, but as an isolated system powered from the Van Nest substation. Control of the catenary system was transferred from Cos Cob to the Load Dispatcher at New York Penn Station. Although conversion occurred subsequent to the PRR-era electrification, Amtrak substation numbers 45-47 were assigned for consistency with the rest of the PRR numbering scheme.
See also
- New York, New Haven and Hartford RailroadNew York, New Haven and Hartford RailroadThe New York, New Haven and Hartford Railroad , was a railroad that operated in the northeast United States from 1872 to 1968 which served the states of Connecticut, New York, Rhode Island, and Massachusetts...
- Metro-North RailroadMetro-North RailroadThe Metro-North Commuter Railroad , trading as MTA Metro-North Railroad, or, more commonly, Metro-North, is a suburban commuter rail service that is run and managed by the Metropolitan Transportation Authority , an authority of New York State. It is the busiest commuter railroad in the United...
Inherited the system after the 1976 bankruptcy of Penn Central. - Overhead linesOverhead linesOverhead lines or overhead wires are used to transmit electrical energy to trams, trolleybuses or trains at a distance from the energy supply point...
- Railway electrification systemRailway electrification systemA railway electrification system supplies electrical energy to railway locomotives and multiple units as well as trams so that they can operate without having an on-board prime mover. There are several different electrification systems in use throughout the world...
- Railroad electrification in the United StatesRailroad electrification in the United StatesRailroad electrification in the United States comprised many different systems in many different geographical areas, few of which were connected. Despite this, there were a small number of common reasons for electrification....
- Amtrak's 25 Hz Traction Power System Built by PRR about two decades after New Haven's
- SEPTA's 25 Hz Traction Power SystemSEPTA's 25 Hz Traction Power SystemSEPTA operates a 25 Hz traction power system in the vicinity of Philadelphia, Pennsylvania that it inherited from the Reading Railroad. This system is separate but similar to the system designed by the Pennsylvania Railroad which is now operated by Amtrak. SEPTA's trains can run over either...
Another 1930s era electrification - Amtrak's 60 Hz Traction Power SystemAmtrak's 60 Hz Traction Power SystemAmtrak operates a 60 Hz Traction Power System along the Northeast Corridor between New Haven, CT and Boston, MA. This system was built in the late 1990s and supplies locomotives with catenary power at 25 kV, 60 Hz...
Amtrak's system east of New Haven.