STEP analysis reveals design problems with Yard 8 maintenance facility

  • Post category:Green Line

The following letter and analysis were sent from STEP to the Executive Office of Transportation.
Dear Secretary Aloisi,
STEP has carefully reviewed the EOT report on locations for the maintenance facility. We found that the state’s decision in favor of Yard 8 failed to account for key operational issues. In other words, there are design problems in the track design for the Yard 8 design. The state’s critique of other locations in the report did not take into account the operational design flaws of the Yard 8 plan.
Concerned that the criteria for evaluating the locations was not consistent, STEP requested that Mr. Stephen Kaiser review and evaluate the operational issues for both Yard 8 and Mirror Scheme H. Mr. Kaiser is a Cambridge engineer who formerly worked for 15 years with the state on matters of transportation and environmental review. Download his summary report of June 26 (PDF).

The essence of his analysis is that the current designs for both Yard 8 and Mirror Scheme H have track designs that will require extensive switching and reversal of direction of trains in order to reach the maintenance facility and storage yards on a daily basis. Each one of these switching operations will result in delays and disruption of service on the Green Line, as well as safety concerns.
The current design of Yard 8 introduces issues of safety and delay when transit officials place cars into service to meet inbound peak service demand. This difficulty arises because the design for Yard 8 shows the storage tracks located on the outbound side of the Green Line. This design will require Green Line LRVs to travel from the storage yards on the outbound track and then switch direction to go inbound. This need for switching will interfere with service and adherence to schedule on both the Lowell and Union Square branches.
The Yard 8 location is very constrained by its surroundings which makes any changes to or expansion of the facility impossible in the future. This is not the case for Mirror Scheme H as the location is next to MBTA owned land that could be modified or expanded if needed.
In evaluating the switching issues Mr. Kaiser identified a better track plan for the Maintenance Facility. The new track design would allow for the simple merging of trains, without the requirement to switch over to the opposite track and reverse the direction of the train. The operational and safety values of this proposed track plan are quite clear.
However, with the improved track plan in place, it is easier to see the limitations of Yard 8, because its narrow and constrained corridor do not allow for the desired design flexibility and expansion capability to offer improved Green Line service in the future. This design flexibility does exist for Scheme H.
The EOT report stated a preference for Yard 8 as the siting for the Maintenance Facility because it offers the most efficient benefits as a location. Unfortunately, EOT’s analysis of proposed alternatives did not equally evaluate the operational issues for Mirror Scheme H and Yard 8. EOT must improve its design for the maintenance facility to account for the abovementioned operational and safety issues. When these operational aspects of EOT’s design are resolved, state and city officials will be able to see clearly the land use advantages associated with Mirror Scheme H with its superior location of the Maintenance Facility and storage tracks.
Finally, we also want to note that both Yard and Scheme H locations for the Maintenance Facility do not raise concerns about the alignment of the route of the Urban Ring from Sullivan Square through Inner Belt to Lechmere in the EOT reports. We want to make sure that as planning goes forward for the Green Line extension and the Urban Ring that engineering planning and design for both projects accommodate the Urban Ring alignment through Inner Belt.
Ellin Reisner, President, STEP