08 April 2014

HSR Peer Review Group on Blending

The California High-Speed Rail Peer Review Group was established by AB 3034 (the Proposition 1A bond law) to independently review the HSR Authority's plans, assumptions, analyses and estimates.  The Peer Review Group recently sent the legislature its comments on the Draft 2014 Business Plan, including a number of recommendations concerning the plan to "blend" HSR and Caltrain on the peninsula corridor.  The Peer Review Group comments on blending follow:
Blended System issues. Access to San Francisco’s Transbay Terminal has posed a challenge to the program from the beginning. The ideal engineering outcome – a new, four track system separating HSR from Caltrain and freight service – was problematic because of its high cost and environmental impact. An alternative approach was adopted that blends the services of Caltrain and HSR on the same two track system, mostly within the existing right-of-way but with specific additions of passing tracks where needed and with the possibility of incremental increases in capacity when justified by demand. When combined with electrification of the Caltrain lines, paid half-and-half by Caltrain and HSRA, this approach should work to serve the needs of both systems at least through the first decades of the Phase I Blended system. In a number of our previous letters, the Group has supported the blended system approach; our comments below are aimed at improving its implementation.

The blended approach will require a true joint effort by Caltrain and HSRA with full participation of other parties including the Transbay Joint Powers Authority (that has the responsibility for the connection from the current Caltrain terminus at 4th and King Streets to the Transbay Terminal) and the Union Pacific Railroad (that has freight operating rights on the same lines). There are a number of issues on which the interests of the parties must be explicitly balanced if the blending is to work:
  • Currently, Caltrain uses a platform height of 8” above rail. This means that boarding/de-boarding requires stepping up/down from the floor of the train (25” above rail), which can impose delays and risks of tripping and falling, especially when the needs of disabled passengers must be accommodated. The result is longer and less reliable schedules. The low platform height is dictated by the regulations of the California Public Utilities Commission (PUC) that require platforms to be no higher than 8” on tracks that may also carry freight trains. Unless a waiver from this regulation is granted, or expensive track work is installed, Caltrain will be limited to low platforms. At its current frequency of services, the lack of level boarding is manageable (if undesirable), but it will become much less tenable when Caltrain frequencies are increased and HSR trains are added.
  • Under current plans, the floor of HSR trains will be about 50” above the rails, which is typical practice for most of the world’s HSR systems and consistent with Amtrak’s plans in the Northeast Corridor. Caltrain is experiencing rapid demand growth, a process that will accelerate when service to the Transbay Terminal is inaugurated. Caltrain’s plans call for acquiring new bi-level, electric multiple-unit rolling stock. Since the existing Caltrain coaches have a 25” floor level, consistency would suggest a 25” floor level for the new equipment. This would mean that platforms for the two systems would be at different levels, making transfers within station more difficult to arrange. This might be manageable at many common stations where Caltrain and HSR could have separate platforms, but the platform disparity would be more serious at the Transbay Terminal because the number of platforms is limited. As a result, routing of traffic into and out of the station will be more complex, and dispatchers will not have the flexibility to send either system to all platforms when delays or operating problems would otherwise dictate. One approach, turning a number of Caltrain services at 4th and King and limiting the number of Caltrain services to the Transbay Terminal, has been suggested, but would pose restrictions for Caltrain’s access to the Transbay Terminal.
  • The basic standards of the PUC for electric catenary wire call for a clearance of 22 feet 6 inches above the rail. One the one hand, both Caltrain and HSR may want a lower catenary height in order to reduce construction cost for which the PUC will have to grant permission: on the other hand, the Union Pacific and port interests may want to protect the hypothetical possibility of future freight cars requiring even more clearance. HSR’s current electrification designs are appropriate for HSR-only operations and may not be acceptable for use in the Caltrain area. There are a number of specific locations where Caltrains’s clearance is already below 22 feet 6 inches, but there is no generally agreed height limitation.
  • Positive Train Control (PTC) is a requirement of Federal law. Facing this mandate, Caltrain developed its own system – CBOSS – that is now being implemented. CBOSS may not be appropriate for use by HSR trains. If so, HSR trains may have to deal with two signal systems. In addition, the Union Pacific Railroad will have to operate in the same territory so will have to have conforming signal systems in its locomotives. 
None of these problems is impossible to resolve, albeit at added investment and operating cost by one or more of the parties. There is nothing unique about having multiple freight and passenger operators on a single line and there is experience in the U.S. and Europe with resolving the normal issues. All parties in the blended area are aware of the issues and there has been full cooperation among them.

We are concerned, however, that near-term decisions could be made by the parties acting separately that would ultimately compromise the performance of the system. For example, a decision by Caltrain not to plan for at least 25” platforms, which would provide an essential approach to level boarding, would lead to increased delays and uncertainty that could become unmanageable when Caltrain frequencies increase to meet the rapidly growing demand, especially that caused by the opening of the Transbay Terminal. This problem would get worse when four HSR trains per hour are added to the blended system in 2026. Caltrain will definitely need an expanded fleet, and bi-level cars are an efficient way to meet the need. That said, a decision to buy 25” floor level, bi-level coaches would mean that Caltrain and HSR would be committed to operating on incompatible platforms, which would add rigidity to a system that will be challenged for capacity. This problem could be alleviated if Caltrain ordered coaches that can serve both platform levels or if it adopted a uniform 50” platform, but either solution would clearly add investment costs above those planned. In all cases, the design of the electrification for Caltrain will need PUC approval and will need to consider the interests of all of the operators on the line.

This is a complex issue involving technology, investment, system performance and sequencing including the interests of a number of parties. Clearly there is no perfect answer and it is actually a problem resulting from success in attracting more passengers. We recommend that the Legislature request periodic joint reports from Caltrain, HSR and the Union Pacific Railroad that will use the tools available, including line capacity simulators, to assess the impact of alternative approaches to coach floor and platform height on capital and operating cost, capacity and reliability of both systems. This would include the impact on Caltrain if it has to construct 25” or 50” platforms. This study should also include the investment and operating cost impact of the alternative approaches to catenary height and platform clearance and should outline the decisions that the PUC will be asked to make.

Blended operations also pose the issue of accidents at grade crossings. Even at its existing speeds and frequencies, Caltrain experiences about 20 grade crossing and intruder deaths per year and generates delays on the local streets as autos and trucks wait for passing trains. This will get worse as train frequency and road traffic both increase over time. It would be difficult to overstate the risks of more frequent, faster and quieter Caltrain service combined with 110 mph HSR trains interacting with growing road traffic in the middle of California’s increasingly busy cities. We recommend that the Legislature ask Caltrain, HSR and the communities involved to develop a joint report assessing the likely future risks of increasing train traffic and speeds on the grade crossings in the areas impacted and identifying possible approaches to resolving the issue over time.
The Peer Review Group's comments are a wake-up call to start breaking out of the silo mentality that is prevalent in our transportation agencies, where "staying the course" is too often the overriding consideration.  The blend can only succeed if all stakeholders adjust their plans and projects to achieve better coordination and system-level integration.  The Peer Review Group understands that we are at a juncture where this opportunity must not be squandered.

05 April 2014

Saving Some Trees

One of the most controversial elements of the Caltrain electrification DEIR is the need for tree pruning or removal to establish adequate clearance between vegetation and the live parts of the overhead contact system, energized at 25,000 volts or more.  While the exact regulatory details governing 25 kV electrification are still being hammered out at the CPUC, vegetation clearances are likely to be governed by General Order 95, Rule 35, Appendix E, which states:
The radial clearances shown below are recommended minimum clearances that should be established, at time of trimming, between the vegetation and the energized conductors and associated live parts where practicable. Reasonable vegetation management practices may make it advantageous for the purposes of public safety or service reliability to obtain greater clearances than those listed below to ensure compliance until the next scheduled maintenance. Each utility may determine and apply additional appropriate clearances beyond clearances listed below, which take into consideration various factors, including: line operating voltage, length of span, line sag, planned maintenance cycles, location of vegetation within the span, species type, experience with particular species, vegetation growth rate and characteristics, vegetation management standards and best practices, local climate, elevation, fire risk, and vegetation trimming requirements that are applicable to State Responsibility Area lands pursuant to Public Resource Code Sections 4102 and 4293.
10-foot tree clearances, from DEIR
The CPUC rule establishes minimum clearance of 4 feet at the time of trimming, and gives Caltrain discretion to increase the clearance as needed.  Caltrain has added another 3 feet of allowance for wind sway, and another 3 feet on top of that for vegetation growth between trimmings.  This brings the overall clearance carried in Caltrain's DEIR to 10 feet, as shown in the diagram at right.

This 10-foot clearance drives the number of trees impacted by the project: 2,200 are due for removal and another 3,600 for pruning according to the DEIR.

Outside Poles

The standard configuration of the overhead contact system places poles on the outside of the tracks, near vegetation.  The clearances look like this:
This configuration tends to have the worst impact on vegetation, mostly because the 50 kV feeder wires attached to the tops of the poles are near vegetation all along the right-of-way, even in the long open spaces between poles (right-hand diagram).  This is the main reason why 2,200 trees face the chain saw.

Inside Poles

To keep high-voltage components away from vegetation, it is possible to locate the poles between the tracks in the middle of the right-of-way.  This requires slightly more space between the tracks; the regulatory minimum is approximately 18 feet (2x 8'3" minimum from track center line to pole face, plus the width of the pole itself, plus some error margin).  The diagram below shows 19-foot spacing, with taller poles to carry both feeders with adequate clearance from each other:
While this configuration spreads the tracks apart by four feet, the resulting impact to vegetation is less, especially between pole locations, because the feeders are kept away from vegetation.  The down side is that tracks need to be moved apart; this is not very difficult except where cross-overs are located.


Portal gantries are basically the same as side poles, with a cross-bar across the top.  Like center poles, the portal arrangement allows the 50 kV feeders to be located in the middle away from vegetation.  Unlike center poles, portals do not require the tracks to be further apart than 15 feet:
The portal configuration has the least impact on vegetation between poles (right-hand diagram) but isn't particularly beautiful (left-hand diagram).

Most of the 2,200 trees threatened by electrification probably aren't worth saving.  They are typically not "heritage" trees, and consist mostly of unremarkable species that have grown haphazardly into the right-of-way.  But there are surely certain trees worth saving, and for those, the support arrangement of the overhead contact system can be engineered to keep high-voltage feeders away from vegetation, over the tracks.