They are to operate on the Northeast Corridor, between Washington and Boston, and on the Keystone Corridor, between Philadelphia and Harrisburg.
The new locomotives are designed for a top speed of 125 miles per hour and will be among the fastest locomotives in Amtrak's fleet, other than Acela Express trains, which can reach speeds of 150 miles per hour.
After decades of tight budgets and threats of extinction, Amtrak is moving this year to begin to upgrade and expand its fleet of locomotives and rail cars.
Amtrak plans eventually to replace 334 locomotives and 1,200 rail cars.
And, with a push by the Obama administration for high-speed rail service in the United States, foreign train manufacturers like Germany's Siemens, France's Alstom, Spain's Talgo, and others are interested in pursuing contracts to build high-speed trains for the American market.
On Thursday, the U.S. Department of Transportation announced the award of $2.4 billion for high-speed rail projects in 23 states. That was in addition to $8 billion awarded earlier this year.
The new locomotives in the Siemens contract announced Friday won't be capable of true high-speed train travel, which is usually defined as 155 m.p.h. or faster.
Because of Federal Railroad Administration specifications, the new Amtrak locomotives, at about 215,000 pounds, will be heavier than their European counterparts. That may slow acceleration slightly, but will not affect top speeds, a Siemens spokesman said.
The new Amtrak locomotives also will be designed to accommodate the varying electrical systems on the Northeast corridor.
Contact staff writer Paul Nussbaum at 215-854-4587 or pnussbaum@phillynews.com.