In this series published in Railway Age's September, October and November 2015 issues, Contributing Editor Alfred E. Fazio examines the possibilities and engineering requirements for high- or higher-speed rail in the U.S., with emphasis on Amtrak's Northeast Corridor, including an improvement project in New Jersey.
In this series published in Railway Age's September, October and November 2015 issues, Contributing Editor Alfred E. Fazio examines the possibilities and engineering requirements for high- or higher-speed rail in the U.S., with emphasis on Amtrak's Northeast Corridor, including an improvement project in New Jersey.
Part I: DEFINING and EXPANDING HIGH SPEED
The recent nationwide initiative for the introduction of high-speed (or “higher” speed) passenger service in the U.S. has experienced mixed success. While California is progressing on its challenging path to VHSR (Very High Speed Rail), other initiatives have been criticized in political venues for their failure to introduce European- or Asian-style “bullet trains” across America.
Much of this criticism is unfair. In many cases, 100- to 110-mph service that operates with high reliability with reasonable frequencies is sufficient to meet demand and fits within North America’s existing freight railroad framework.
For purposes of this article, the term HSR will apply to services whose maximum authorized speed (MAS) exceeds 90 mph. This is in keeping with the FRA’s approach to safety standards where operation at speeds above 90 mph requires vehicle-specific qualifications and for which Code of Federal Regulations Part G high-speed track standards apply. Also, the term VHSR will apply to speeds of 150 mph or greater.
Thus, on the NEC, only the Acela Express can be considered VHSR, and only on a marginal basis, since the total territory of 150-mph operation consists of approximately 40 route-miles. However, Keystone and Northeast Regional trains (and potentially soon some commuter trains) qualify as HSR. While these categories of VHSR and HSR may not fit well with the Obama Administration’s euphoric visions of creating an entirely new high-speed rail industry (including vehicle manufacturing) in the U.S., they conform to current reality.
There are numerous transportation and system safety issues as well as engineering challenges that form the very essence of the business and safety cases necessary to foster the expansion of HSR in the U.S. Future U.S. new-start (dedicated) railroads suitable for VHSR face the quandary already challenging California: Land is available only where population is sparse (such as in California’s Central Valley), and most existing main line railroads are components of the world’s best freight rail network and therefore not conducive to HSR.
A number of projects have been supported by federal and state grants with the intention of achieving at least representative segments of HSR operation on existing railroads. While some have met with reasonable levels of success, none have resulted in high-speed operation over sufficiently long segments. Notable have been enhancements made to Union Pacific’s Chicago-St. Louis line to achieve passenger train speeds of 110 mph. Also noteworthy are the enhancements in progress to the Amtrak/Norfolk Southern Michigan Line.
Other projects funded through the Administration’s HSR initiatives, such as enhancements to the CSX RF&P Subdivision, including new interlockings and addition of a third main between Fredericksburg and Alexandria (40 miles); restoration of the second main track on Amtrak’s Schenectady-Albany route on the Empire Corridor; and restoration of the second main on the former New Haven Railroad’s Hartford line, improve fluidity and velocity of passenger train operations but do not raise MAS above 90 mph. Thus, for these types of projects to be portrayed as HSR initiatives is somewhat stretching the facts.
An exception to the quandary of available main lines vs. population density is, of course, the NEC and its three branches (Harrisburg, Hartford, Empire). Future improvements to the NEC or the associated 100-mile-long Harrisburg Line may well be the HSR initiative, other than California, that serves as a benchmark for future HSR or VHSR in North America. This railroad is to the Northeastern U.S. what the California Water Project is to California.
The Water Project must satisfy the demands of the megalopolis of Southern California for potable water, and at the same time it must continue to irrigate the rich farmlands of California’s Central Valley. So must the NEC satisfy the demands of multiple users: local commuter trips, HSR, and intercity trains that serve off-corridor destinations. This railroad, particularly the 270 miles between New York and Washington, serves a wide variety of users, many of whom place different, and at times conflicting, operational and engineering demands on the infrastructure. In addition to the existing HSR (Acela, Keystones, Regionals), the railroad carries an increasing number of commuters and also serves as a terminal railroad distributing and collecting passengers for Amtrak’s Eastern Seaboard long-hauls. At the same time, certain portions are seeing a resurgence in freight (for example, crude oil trains operating in Delaware and Maryland).
Concept of Operations
The original Northeast Corridor Improvement Project (NECIP) of 1976 to the mid 1980s established an operational configuration that supported Metroliner speeds of 125 mph and Northeast Regional speeds of 110 mph. Since that program, Amtrak has pursued an incremental approach to upgrades, achieving Acela Express speeds of 135 mph in the New York to Washington D.C. segment and 150 mph in selected New England segments. Speeds for Amfleet equipped regionals now top out at the former Metroliner MAS of 125 mph. The early NECIP Concept of Operations (CONOPS), which will be reviewed in Part II (October issue), was largely a derivative of rapid transit-type thinking: a double-track high-speed “express” railroad superimposed on a three- and four-track railroad, with locals on the outer tracks and all freight except local freight moved to the parallel CSX main line.
In development and deployment of complex engineering systems, particularly those with complex subsystems (train control, traction power, vehicles), everything must be highly integrated to achieve the total system’s target performance. The CONOPS is the basis for developing a formal Program Requirements Document (PRD). The CONOPS explains what the fully integrated and deployed system is intended to do—how it operates, clarifies its performance targets and verifies its ability to achieve its stated mission.
The CONOPS also addresses maintenance requirements and considers partially failed operational scenarios. The PRD, in turn, is accompanied by a robust safety case to become the basis of design criteria development. These criteria then guide the basis of engineering design and engineering maintenance throughout the program life. A change in CONOPS invariably leads to a reconfiguration or replacement of one or more engineering subsystems. For several reasons, the original NECIP CONOPS no longer applies to the NEC.
The Future of the NEC
In addition to operational and engineering considerations, governmental factors (e.g., PRIIA legislation that arguably makes the NEC less of an Amtrak rail property and under which the NEC may take on the characteristics of a jointly operated terminal railroad) justify reconsideration of the extent and nature of achievable HSR in the Northeast. The short version of this complex issue resembles a simple good news/bad news joke: The good news is that in the future, commuter service will pay fully allocated costs; the potential bad news (at least for HSR) is that the commuter agencies will have significantly more to say about the engineering configuration and operations of the railroad. The particular question is, given these factors, what is next for the NEC?
Considering the future of the NEC helps answer the more general question: What are the factors governing the expansion of HSR (passenger service at 90 to 125 mph speeds) on railroads other than the NEC? The balance of this article (Parts II and III, in the October and November issues, respectively) will explore some of the engineering and operational factors that have matured over the past 40 years as part of Amtrak’s incremental approach to NEC upgrades. In particular, the experiences of the past three to four years on the benchmark New Jersey High Speed Rail Improvement Project (NJHSRIP) will be reviewed. The focus will be on engineering and operational factors, and the reader must be mindful that other considerations such as political factors and business cases are also relevant. Like it or not, however, it is the engineering and operational factors that form the others.
Concepts espoused for the NEC’s future vary widely. One extreme is the so-called “Next Gen” Program, which essentially consists of “selling the house and moving.” The advertised price on this option was $150 billion. Given the history of major infrastructure works in the Northeastern U.S. (Boston’s Big Dig and the LIRR’s East Side Access), a more reasonable estimate for the cost of a new and parallel VHSR corridor is likely to be somewhere north of $300 billion.
At the other extreme is the concept of retaining status quo on the NEC with emphasis on State of Good Repair (SOGR). A more reasonable future might consist of selected Next Gen segments combined with continual incremental upgrades of the existing railroad. Presumably all of these concepts are under review by qualified professionals under an NEC Futures study sponsored by the FRA. The results of this study are anxiously awaited by all who have an interest in NEC. The analysis, one hopes, will be based on fact and not wishful thinking. An important ingredient in this effort should be hard data regarding the cost and service impacts of major upgrades to the NEC. Parts II and III of this series will speak to what would be considered a beta effort to upgrade the NEC well above NECIP standards and capability: the NJHSRIP.
Likewise, a variety of concepts exist for HSR initiatives “off” the NEC or CHSRP. Unfortunately the processes that determine future directions for HSR often ignore or greatly downplay engineering and even operational factors. As some so-called “policy makers” offer, “this decision is too important to be left to the engineers.” The pitfalls of ignoring engineering are manifold and include, but are not limited to: cost overruns, failure to achieve operational objectives, and ultimately, train wrecks.
A number of years ago, at a Railway Age “Passenger Trains on Freight Railroads” conference, a briefing was given on a proposal to add sidings to accommodate the superposition of passenger service in the 100 to 110 mph range on a busy freight main line in the western U.S. A question was raised by a well-seasoned transportation officer as to the length of siding needed to effect unimpeded overtakes by high-speed passenger trains.
A simplified analysis of the layout of such a siding, one that would be suitable for a high-speed overtake of a fast freight train, serves to illustrate the operating challenges associated with superimposing HSR upon existing freight main lines. For a high-density double-track railroad with a freight MAS of 60 mph and a passenger MAS of 110 mph, an exercise to develop a typical design for a siding or section of triple-track suitable for overtakes provides a number of insights into design of “joint priority” shared-use railways. Joint priority means that HSR trains and through freights are considered as “first class” trains. Such configurations once repeated common layouts on mixed-use railroads, such as on the former New Haven Shore Line, where a section of triple-track existed in the vicinity of Kingston, R.I., intended for passenger train overtakes of freight.
Assuming a “clean” overtake, where neither train suffers a speed downgrade, a freight speed of 60 mph, and a passenger speed of 110 mph, a third main track of slightly greater than 7 miles is required for a perfectly scheduled and executed overtake. If a reasonable schedule tolerance of 5 minutes is introduced, the required length extends to 17 miles. Note that on a joint priority railroad, this length is necessary, since neither train should be held for the other. Not considered here are other operational and safety factors that must also be introduced into the design criteria, including track centers (will they be 17 feet or will they be even greater?), movement of hazmat trains, flexibility of train movement scheduling, and dispatcher choices/priorities for delay recovery.
This is not to say that the engineering and operational challenge of superimposing HSR on heavy freight lines are insurmountable. Railroads of two generations ago were able to find adequate solutions. The question reduces to this: At what cost can engineering, operational and safety factors be addressed? All of these costs must be adequately represented (and paid for) and considered in a comprehensive business case. The NEC as the Beta Site
Moving beyond California High Speed Rail and other potential new-starts where new alignments may be constructed, and where the selected test cases where HSR is to be superimposed on freight main lines, leaves one significant opportunity where population density and travel demand match the available main line. This is the Northeast Corridor, including the lines to Harrisburg and Albany. This well-endowed railroad services millions of people within its service area, and it already is devoted primarily to passenger (albeit other than HSR) use.
The first lesson from the NEC is that the practical limits on the extent of incremental HSR upgrades are largely driven by the intense demand for other uses (non-HSR intercity, commuter, freight) as much as by physical plant limitations and cost. As a consequence, the feasibility of high-speed trains exceeding 160 mph on the NEC is extremely remote. And even if it’s feasible, the utility and practicality of, say, 300 kph (186 mph) operation is problematic.
Consider a history lesson from another engineering-based industry, aviation. In the early 1970s, years of technical and marketing research indicated to the British and French the practicality of and commercial case for a civilian supersonic passenger aircraft, leading to the deployment of the Concorde Supersonic Transport (SST). Likewise, after careful consideration, Boeing elected to not build a version of the SST, and to invest instead in the 747. Boeing’s analysis considered a wide variety of factors, including the reduction in total trip time achieved by the SST, cost of service delivery, passenger comfort, and environmental (specifically, the anticipated restrictions on exceeding Mach 1.0 over land). Today, Boeing is still building 747s, while the few Concordes built have all been withdrawn from service.
PART II: FEASIBILITY vs. COMPLEXITY
Installation of VHSR on a scale that really matters will require new-start railways, such in the case of California HSR. Although there is much discussion on other new-start opportunities, there is little of consequence outside of California, where speeds are targeted at greater than 135 mph. Considering the VHSR threshold at 150 mph, there is the existing (albeit limited) VHSR on the New England Division of the Northeast Corridor, although there also is some progress and additional potential for superimposing HSR at the lowest end of the speed regime (say 90 to 110 mph) on existing freight main lines. Speeds above this regime are not likely to be achieved on freight-oriented main lines. It is also noteworthy that a number of passenger railroads exist other than Amtrak (LIRR, Caltrain, Metro-North), and none of these have targeted speeds above 90 mph. This brief survey leads us to consider what can and should be done to exhibit HSR on the NEC (including the Harrisburg and Empire/Albany lines).
There are two distinct issues: What can be accomplished speaks to feasibility; what should be done is more complex and must consider competing uses of the railway fixed plant as well as budget (along with competition for increasing limited funding). These are related. Realigning a curve in four-track territory to remove or mitigate a speed restriction might be feasible if two of the tracks were removed, thereby making the entire width of alignment available for “best fit” two-track geometry, but given the increase in frequency of all train types, such an option may not be feasible.
The next upgrade of the NEC bears careful consideration: What maximum speeds are realistic (feasible) on a railroad built to nominal 12.5-foot track centers. In fact, some track centers are as low as 12 feet 2 inches, and what might be the implications of these track centers at trains passing at a relative speed of 300-plus mph? Likewise, what is the cost/benefit (practicality) of raising maximum speeds between New York and Washington to various benchmarks above the current 135 mph, where MAS above 135 mph for stretches of 10 to 15 miles have no effective impact on schedule running time?
New Jersey High Speed Rail as a “Beta Release”
The New Jersey High Speed Rail Improvement Project (NJHSRIP) represents a tangible effort, one that is of sufficient size to test various options for NEC upgrades beyond NECIP standards. The program is based upon a $459 million grant awarded to Amtrak in September 2011 to build the prototype section of the future NEC, and to evaluate both its operational performance and maintainability.
NJHSRIP involves complete rebuilds, to modern designs, of traction power and signal power distribution systems; upgrades to the capacity of the 60/25 Hz electrical conversion capability; totally new cab/no-wayside signalization; and addition of high-speed interlockings over a 22-mile segment of NEC in New Jersey. Limited track and structural improvements (outside of interlockings) and minor realignments are also included in the scope; but since track and bridges were emphasized in previous programs, under NJHSRIP they are of secondary priority.
The terms of the DOT grant require Amtrak to perform to a specific schedule and complete work to a lump sum budget. Speed enhancements specified under the grant require a new MAS of between 160 and 186 mph; MAS has since been agreed upon by Amtrak and FRA to be targeted at 160 mph based upon a safety case. The grant territory extends from New Brunswick to Trenton (Hamilton), N.J. Within the framework of performance goals, selected (but not specified in detail) scope elements and service outcomes, Amtrak has been afforded the opportunity to develop a detailed scope, engineering standards and design.
The territory affected by the grant supports all three types of Amtrak service including Acela Expresses at 135 mph, Regionals and Keystones at 125 mph and long haul at lower speeds. High-speed NJT commuter (90 mph) and local (but not through) freight also operate. The new higher MAS will apply to VHSR trainsets only, presently Acela, and then later the Tier III Acela replacements now in procurement. Raising speed to 160 mph will result in approximately 50 seconds reduction in running time over the 22-mile segment.
Those unfamiliar with the stepwise evolution of engineering designs and standards or who may hold unfavorable views of investments in high-speed rail will readily observe that the apparent benefit of this grant can be calculated at about ten million dollars per second saved in scheduled running time. This superficial view does not consider the enhanced reliability as well as the increases in commuter and regional train capacity that will result upon completion of work in summer 2017.
Even these factors are subordinate, however, to the recognition that the 22 miles affected by this grant serves as a “beta” site for four independent but related proofs of concept. The first beta factor is the engineering effort, which includes establishing new design standards and installation/maintenance requirements for totally new signaling and catenary designs. A 9-aspect cab signal system will permit NORAC Rule 562 (bi-directional train movements on signal indication with home signals only) operation on all tracks.
This is an entirely new train control system that does no harm to freight, and that actually increases commuter/regional train capacity. The new train control is currently in service over 10 miles of the territory. Approximately 10 miles of catenary will be rebuilt as fixed, not constant-tension, to a modern and more fault tolerant design where independent registration will replace the PRR original design that utilized body spans. Installation and maintenance cost libraries will be developed, as will serviceability data, with an aim toward guiding future choices regarding NEC upgrades.
Second is the ability to upgrade the MAS of high-speed trains while benefiting other rail services. This was accomplished largely through development of a revised CONOPS, careful placement of interlockings, and additional investment in selected subsystem designs. Also helpful was the generous four-track right-of-way. Raising MAS will generally have a deleterious effect on capacity where the physical plant is not as generous. In fact, based upon train length, braking rates and philosophy of signal block layout, maximum track (line) capacity generally occurs at speeds between 30 and 50 mph.
Third is formulation of a System Safety Program Plan (SSPP) in accordance with Mil STD 882. While all new FTA-funded transit systems must develop such a plan, this practice is relatively new to FRA, where prescriptive standards have generally been the rule. Under new FRA practices, authority to operate the improved high-speed service will only be granted where prescriptive standards are complemented by a full safety case.
For the NEC, the SSPP will be developed in two parts: an initial case to permit Tier II (Acela) trainsets to operate at 160 mph on the present 150-mph territory in New England, followed by a site-specific case in New Jersey allowing 160 mph on designated segments between Hamilton and New Brunswick. The SSPP must address site-specific issues as well as more general considerations. Thus, it is possible that one segment may be approved for 160 mph operation while another that has only slight variations in the environment or usage would not be approved, despite the fact that the engineering systems are designed and installed to the same standards. Ultimately, the Tier II case becomes an ingredient in Tier III (lightweight VHSR trainsets) operation.
The final element makes Amtrak effectively a DBOM contractor working to a hard schedule: All work must complete prior to June 1, 2017 and within a lump sum budget of $459 million. This has led to some challenging scenarios. Conversely, a benefit is the departure from the annual funding process that hampers Amtrak in developing a rational, multi-year capital program. In this case, Amtrak has clear funding for the 5½ year (October 2011 through June 2017) duration of the grant. The challenges have also led to creative solutions for particular issues such as a project labor agreement with BMWE allocating composite gangs.
CONOPS, Program Requirements, Development of Scope
The award of the $459 million dollar defined “period of performance” contract to Amtrak was primarily based upon performance outcomes, as differentiated from an engineering-based prescriptive definition (drawings and specifications) of work to be performed. For example, interlocking improvements required to support HSR were called out, but the location, configuration and diverging speeds were left to Amtrak and FRA to develop, with the cooperation of the other users (NJT, Conrail). A similar requirement applied to the resignalization, where the contract required higher speeds (160 to 186 mph), higher reliability and greater capacity, but did not specify the signal design or block layout.
Because the grant allowed latitude to develop scope according to the desired performance of the rebuilt railroad, the first priority in scope development was, along with the SSPP, Amtrak’s formulation of the CONOPS and obtaining the concurrence of FRA, NJ Transit, Conrail, NS and CSX.
Figures A, B and C show the successive CONOPS developed for this railroad, beginning with the PRR’s mid-1930s concept around which the original AC electrification was installed. The PRR’s operating concept underwent a dramatic change with NECIP. Figure B represents the circa 1976 CONOPS of an express (HSR) and local configuration, mimicking a four-track rapid transit line, with HSR diversions planned to be made to the opposite high-speed track. This CONOPS led to an early NECIP design criteria: that high-speed funds could only be expended on either of two designated high-speed tracks between New York and Washington.
Figure C represents the CONOPS that was developed for NJHSRIP, still with HSR on the center tracks (2 and 3) but with two major variations on the NECIP concept. First, high-speed (100-mph) NJ Transit trains are also on the inner tracks operating as “Zone Expresses” until they make a high-speed diverge to the outer tracks. Second, due to high train density on Tracks 2 and 3, the plan calls for high-speed trains to diverge around an obstruction (failed train, track obstruction or planned m/w work) using the outer (1 and 4) tracks.
This CONOPS leads to requirements that are incorporated in the NJHSRIP PRD (Program Requirements Document).
• Single-direction 80-mph crossovers installed at the outer end of NJT’s Middle Zone, roughly MP 33. While originally symmetrical, the eastward crossover was relocated three miles west, thereby creating an additional interlocking to accommodate NJT’s CONOPS for a proposed mid-line turnback loop and servicing facility. The incremental cost of this additional interlocking was absorbed by a grant contingency.
• Maximum cab speed on the outer tracks would be raised from 100 mph to 125 mph to accommodate high-speed trains that may be required to diverge onto them. Only Amtrak trains receive the 125 mph or higher cab codes; NJT commuter trains will get a maximum speed code of 100 mph.
MIDWAY Interlocking (MP 41.7), which had remained untouched through NECIP and is essentially in its 1935 configuration, would be totally reconstructed. There would be no scheduled train movements, so it would be rebuilt with wider (15-foot vs. 12-foot, 4-inch) track centers with concrete-tie turnouts, but all four tracks would utilize No. 20 (45-mph diverge) turnouts. NJT desired use of No. 20 turnouts rather than 80-mph crossovers at this location on account of lower maintenance costs. Under the older NECIP CONOPS, the two center crossovers would have been configured for 80-mph diverging movements.
To accommodate the requirement for raising capacity as well as achieving an MAS of 125 mph on Tracks 1 and 4, signal block length was shortened to 3,000 feet while the average block length on Tracks 2 and 3 is approximately 4,500 feet. Thus, there are approximately 12 more signal locations on the outside tracks than on the inside tracks.
In order to accommodate freight operation (braking distances and local switching) a cab no-wayside design was employed. All four tracks will be signaled for Rule 562.
To accommodate commission-hour capacity in case of a train with a cab signal failure and with two major stations between Trenton and MIDWAY Interlocking, controllable (block limit) wayside signals are installed at Princeton Junction, but there will be no crossovers at this location.
The scope of each rail system (traction power, signal power, supervisory control, right-of-way) was, in a similar fashion, based on a formal PRD. This was followed by a strong system integration/scope integration effort to insure that the required outcomes would be achieved, and that the maintenance requirements would be understood. This all occurred with participation by FRA and the other NEC users.
The required deployment plan and associated transportation impacts were defined. Interim equipment (for example, roll-in/roll-out temporary high-level station platforms that would cover the full length of a 12-car train) were developed. The safety of interim conditions and work methods was also documented in a formal Safety Management Plan (SMP), which is a support document to the SSPP that insures safety of operations, passengers and work force while on the path to the final configuration. The SMP augments and supplements Amtrak’s safety and operating rules.
PART III: THE DEVIL IS IN THE DETAILS
While so-called “policy makers” generally practice the proverbial 50,0000-foot view, it is necessary for someone else to be (also in the proverbial sense) “in the weeds,” that is, checking the landing gear. This is a requirement to ensure that the “aircraft” will bring the “policy” folks to a safe landing. The saying of a few generations ago was that “the devil is in the details.” Large engineering programs succeed or fail on details rather than general concepts. Given that the concept of upgrading the NEC beyond NECIP functionality and criteria to those associated with VHSR (very-high-speed rail) is a good objective, it is necessary to look at some of the details in order to ascertain if this objective is desirable—that is, is the payback worth the cost and effort? As noted in Parts I and II, the New Jersey High Speed Rail Program (NJHSRIP) provides the primary source of data for such an analysis, particularly with respect to the cost data, including service impacts and production time as well as money. This program is also one of the primary data sources for the benefit side.
The NJHSRIP is being executed on a fast-track schedule, effectively as a design-build rather than a design-bid-build effort. The Program Requirements Document (PRD) along with the System Safety Plan established much of the design criteria for the individual rail systems (track, traction power, right-of-way, train control). Since it was necessary to commence fabrication, installation and construction prior to completion of all designs, a robust system safety and systems integration effort was employed from the program’s inception. The development and execution of the program is best reviewed by considering original design concepts; design changes necessitated during installation/construction and integration of the independent rail systems to optimize investments; innovations, including technical and business methods; and system safety requirements.
Original design concepts
NJHSRIP’s signalization design was a derivative of the HDIS (High Density Interlocking Signal) system deployed in the mid-1990s on the High Line, the two-track portion of the NEC between Newark and New York. This is a fixed-block, nine-aspect, cab/no-wayside ATC system that is not to be confused with ACSES (Advanced Civil Speed Enforcement System, Amtrak’s version of PTC, an overlay on the basic ATC system). Codes are delivered at two separate and distinct frequencies.
The second frequency gives the speed upgrade. Only selected trains are able to read it. For example, Amtrak trains are capable of reading the codes for MAS (maximum allowable speed) of 125 mph. Freight trains, which do not operate on the High Line, were assigned an MAS of 50 mph. This assignment was jointly worked out by Amtrak with Conrail, CSX and Norfolk Southern, and required FRA concurrence. This route and aspect will become the new NEC standard for cab signals/ATC.
Of note is the block layout. Because of the CONOPS (Concept of Operations) prescribing the primary diversion route of a high-speed train to an outside track, it was necessary to provide at least a 125-mph cab speed on tracks 1 and 4. It was also desirable to provide higher capacity (within the 90- to 100-mph speed regime) on these tracks.
This necessitated the use of extremely short blocks. Where 4,500-foot blocks were used on the inside (No. 2 and No. 3 HSR) tracks, 3,000-foot blocks were used on tracks 1 and 4. Figure 1 provides a typical arrangement of blocks, comparing tracks 1 and 4 with 2 and 3. Thus, as a direct result of the operational requirements as expressed in the CONOPS, signalization of the outside tracks was significantly more costly than on the two designated high-speed tracks. Presumably, this concept will also apply elsewhere on NEC, since it provides a workable solution to the capacity lost when signaling for the long braking distance required for VHSR. This allows the superimposition of VHSR on sections of the NEC that also support heavy commuter traffic, without degradation to commuter train capacity, assuming such capacity is based upon 90- to 100-mph braking.
Since the track in this territory has traditionally been well-constructed and maintained, most of the improvements were limited to interlockings. However, MIDWAY interlocking at MP 41.7 was the exception. A universal interlocking consisting of all No. 20 (45-mph) crossovers, MIDWAY’S retirement and replacement with a high-speed interlocking had been planned since NECIP. Such planning at the policy level gives budget makers an opportunity not to invest, and as a consequence this interlocking, located within the existing 135-mph territory, was in questionable condition.
For example, gas-fired switch heaters fed from wayside propane tanks were still in use. These heaters are routinely blown out by the passage of high-speed trains, thereby requiring full-time coverage by B&B employees during storms. Based upon the CONOPS, train movements presently scheduled at MIDWAY will be relocated to the two new high-speed (80-mph) interlockings located at DELCO (MP 32) and ADAMS (MP 34). MIDWAY will remain for use only as a “block breaker.”
After significant internal debate, the decision was reached to replace MIDWAY with new crossovers, but these would again be No. 20s, suited for 45 mph, not high-speed crossovers. This decision was driven by maintenance costs and continuing reliability as much as by capital costs: A four-track universal interlocking comprised entirely of high-speed crossovers would be nearly two miles between opposing home signals and would contain 60 switch machines, all equipped with snow melters. Performance of such relatively simple requirements as FRA-mandated monthly obstruction tests become a challenge.
One major improvement was the widening of track centers within the interlocking from 12.5 feet to 15 feet. This allowed improved crossover geometry. Former NJ Transit Vice President Rail Operations Kevin O’Connor (now with Metro-North) fully concurred with this decision, based on reliability considerations.
Minimal bridge work was required. At certain locations adjacent to roadways, however, the safety case mandated installation of automotive-type guardrails to serve as barriers against vehicular intrusion.
The most significant right-of-way improvements centered on improved drainage and placing the new signal houses at an elevation to accommodate a major flood. A speed-restricted reverse curve limited to 130 to 140 mph depending on equipment considerations exists between MP 39 and MP 40. The original concept called for realigning these curves to achieve 160 mph; this proved impractical from environmental (wetlands), property-taking and cost viewpoints, so the alignment will remain as is. This decision would be important to the cost containment required for catenary renewal. It was also desirable to widen track centers from the nominal 12.5 (and in some cases lower) feet. This was accomplished at interlockings, but for institutional reasons not throughout the designated 160-mph territory, resulting in other safety mitigations.
Improvements to the electric traction (catenary) system include a new frequency converter rated at 70 to 80 megawatts located at the existing 25-MW facility in Metuchen, and a new substation near Trenton. A new cable-in-trough signal power distribution system will replace the original Pennsylvania Railroad open-wire aerial distribution. This is expected to significantly reduce weather-based failures.
The original program scope also called for installation of independently registered constant-tension catenary over all four tracks for the full program length (MP 32 to MP 54). The conversion to constant-tension catenary proved to be one of the most problematic aspects of the program. The original PRR catenary is a heavy-duty, fixed-tension system with its own 25 Hz, 138 KV transmission lines carried on an overbuild.
The presence of a commercial utility overbuild (Public Service Electric & Gas) atop the railroad overbuild raised significant constructability and work scheduling issues. The existing catenary poles are spaced approximately 250 feet apart along the right-of-way. Placing new poles at 180 feet apart or less would require an outage of the utility lines, and ultimately their relocation to new structures.
The trolley wire and associated auxiliary and messenger wires for each track are generally supported by body spans—cabled assemblies that span all four tracks and supported by catenary poles on either side. Under this design, a pantograph-caused dewirement on one track is likely to tear down catenary on adjacent tracks.
A major improvement to reliability will be attained by replacing the body spans with a beamconverting each location to a portal structure. Thus, all new or converted structures will be portals, allowing independent registration of catenary over each track (below) directly to the new portal beam.
The original design concept was based on optimization of pantograph/wire dynamics for a 160-186 mph speed regime. This design called for spacing of portal structures at variable distances, but in no case could the new structure spacing exceed 180 feet with a constant-tension wire design. This created several major constructability, investment cost and maintainability challenges, including:
• Construction of new foundations along an active right-of-way, part of which is through designated wetlands.
• Erection of more than 400 portal beams over an electrified railroad that supports 24/7 operations.
• Retention, repair and maintenance of the old catenary structures until the Amtrak transmission lines can be relocated (currently this is not funded). The PSE&G overbuild would also require relocation.
• Coordination with PSE&G and the N.J. Bureau of Public Utilities to obtain the utility transmission outages required for erection of new poles. Since this is an electrical grid trunk line, these outages are seasonally limited, adding an undesirable scheduling constraint to catenary renewal.
Further engineering analysis indicated that speeds on the order of 140-145 mph could be achieved with new fixed-tension catenary using the existing pole spacing, with body spans converted to portal structures. This speed roughly matched that which would be achieved on the existing alignment for the reverse curve between MP 39 and MP 40. Analysis of train performance indicated that, given this restriction, consideration of high-speed braking and acceleration rates showed that a speed in excess of 140 mph could not be achieved between MP 39 and MP 32 (the eastern limit of catenary renewal). Thus, the 160-mph target between the locations was essentially a “paper” speed.
Also, the PSE&G overbuild extends east of MP 32. This, and a curve on a stone viaduct over the Raritan River (MP 31) eliminated any possibility of exceeding 140 mph east of MP 32. In fact, all the way through to Penn Station New York, there is no chance of exceeding even the current Acela Express MAS of 135 mph. East of MP 32, the timetable MAS is 125 mph for only about 10 of the 33 miles. Due to the curve-heavy alignment, there is very little opportunity to increase MAS for any class of train (including the anticipated new Tier III high-speed equipment) above the current timetable speed of 125 mph. Further analysis showed that, between MP 32 and MP 41, the running time difference between 140 mph and 160 mph is less than 30 seconds.
An integrated review of right-of-way, catenary, operational performance and capital and maintenance costs resulted in Amtrak’s decision to retain fixed-tension catenary between MIDWAY and MP 32. Such decisions are common in fast-track design-build programs as program needs are compared to a project’s schedule performance and “hard money” budgets. Such decisions are “made in the weeds,” based on a thorough knowledge of engineering systems, the railroad’s physical characteristics and operational requirements.
Upon review of data and the decision-making process, FRA funding-grant managers concurred with this change. The condition for FRA’s concurrence, however, was that the fixed-tension catenary would be comprised of all-new material and would be designed with portal structures and independent registration. The benefit of retaining fixed-tension catenary could be that the portal beams would be erected on the existing poles without the need for PS&G transmission line outages. As a result, two “beta” catenary configurations will emerge from NJHSRIP: one for fixed-tension and one for constant-tension. Based on their performance, each configuration will evolve to a standard applications design for use on the balance of the NEC.
Many of these adjustments, such as the catenary changes, were driven by the hard money ($459 million)/hard schedule (5.5 years) requirements delineated in the grant. Part IV will discuss some of the innovative methods employed to achieve the grant requirements, including a special project labor agreement with BMWE.