by TIM BOND
Last night Metro held an open house detailing the initial findings of the Trolley Evaluation Study. The purpose of this study was to determine if the purchase, operating and maintenance costs of electric trolleybuses exceeds that of diesel-electric series hybrids. The initial findings, released two weeks ago, summarized the preliminary findings, indicate that electric trolley buses outperform diesel hybrid buses in comparisons based on cost, energy, and environmental effects. This study is not about whether or not the trolley system should be expanded or what the new buses should look like (e.g. three door boarding).
The presentation provided a few more concrete numbers. It is important to note that the study was based on present-day facts and figures and not projections or speculations. For example, one citizen at the meeting suggested that ridership would improve with the purchase of trolleys over hybrids. Metro reps suggested that was speculation, and that the study would assume ridership was not affected by bus type.
The FTA standard for the vehicle’s useful life is 15 years for a trolley and 12 for a diesel hybrid. The cost difference for 60 foot buses is $1.285m for a trolley vs. $785,000 for a hybrid. Because there are many manufacturers offering hybrid buses, the figure for hybrids was easy to obtain. Since fewer manufacturers produce trolleys, these numbers were based on those paid by other North American agencies and quotes from manufactures such as New Flyer and Vossloh Kiepe. This annualized cost for this report was calculated over one life-cycle for each vehicle type. Also included was fixed-guideway grant money—something the feds give out to operators of trolley networks. This money would mostly be used to cover the difference in capital cost of the trolleys. Not included in the 2009 audit but evaluated here were the costs to decommission the trolley infrastructure ($37 million) and the costs to expand fuel capacity at the base ($5 million). More after the jump.
The initial pamphlet indicated that Metro is only pursuing trolleys with an Auxiliary Power Unit (APU) to allow them to travel off-wire. Two types of APUs were evaluated—diesel and battery—and more detailed numbers were released in this presentation. Diesel APUs, which are used in Philadelphia, have a range of 150 miles compared to battery APUs’ range of just 2.5 miles. Battery APUs are used by trolleys in San Francisco, Dayton, OH, Boston, and Vancouver, BC. Metro hinted that these numbers were based off older technologies, and that technological advancements in the near future might push that to four or five miles. Battery APUs also allow for a maximum speed of 40 mph versus 25 for diesel APUs. Battery APUs also fare better in acceleration and “cutover” time because they are all electric.
Because of their electric motors, trolleys can accelerate and travel at faster speeds on steep grades. Metro compared these to hybrids that would be geared lower to help them climb grades. Being geared lower also limits their top speed. Trolleys, however, are limited by the APU in how far they can travel off wire.
The report assumed that trolleys would put out 304 metric tonnes of CO2 emissions annually compared to the hybrids’ 6,625. 2% of Seattle City Light’s energy comes from non-clean sources.
For visual impact, the study assumed that something that blocked the view of anything was a negative impact. In this report we have a new Photoshopped picture of Rainier with and without overhead wire. Because there are trees and power lines hanging over the trolley wire, the change is subtle. The same can be said for the view off the Jose Rizal Bridge that we saw in the pamphlet. Personally I would have chosen a photo of the 44 wire at 55th & Market in Ballard to show how much of a difference removing the wire makes. But the wire isn’t always bad—one citizen reported that he enjoys seeing the wire throughout his neighborhood as it reminds him of Seattle’s streetcar heritage.
Most interesting is the table showing what would be required to make diesel hybrids more cost effective. Any of the following would do the trick:
- Fixed guideway funding would have to reduce to 31% of its current level
- Electricity prices would have to increase 20% per year
- Diesel hybrid bus lifespans would have to increase to 17 years (currently at 12)*
- Trolley bus purchase price would need to increase by 34% or hybrids would have to decrease by 48%.
Metro would like your feedback on this report through May. Network expansion, what color the buses will be, or how many doors or seats they have is not under consideration at this time. They’re looking for anything they may have omitted in the study. The findings from the study will be incorporated into Metro’s 2012-2013 budget to be approved by the county council this November.
*Metro has had a history of running buses past their useful lives.