The second order is for 175 engines, to be installed by 2004 in new buses manufactured by North American Bus Industries (NABI) of Anniston, AL. A previous order in May 2001 was for 124 engines for NABI buses to be delivered by 2003.
Each order includes an option for the MBTA to acquire up to double the number of buses ordered. If the options were fully exercised, the number of engines involved would rise to 598. Without taking the options into account, the orders allow the MBTA to retire more than a third of its diesel buses.
Both Boston bus orders involve the Cummins Westport C Gas Plus, an 8.3-liter, 280 horsepower engine. The engine was introduced to the market in June 2001. It is a natural gas version of the C8.3G that Cummins began producing in 1996. The C8.3G Plus is designed for buses and trucks and can operate with either compressed natural gas (CNG) or liquefied natural gas (LNG).
The Boston buses will use CNG and will mainly be assigned to urban core routes.
