HHP-8 - History and Design

History and Design

An initial order of 15 HHP-8s was made by Amtrak at the same time (~1999) as the acquisition of the Acela Express trainsets; the locomotives have similar external styling as the Acela trainsets, but are designed to operate as true locomotives, hauling conventional passenger rolling stock. The units were ordered to replace Amtrak's GE E60s and supplement the aging EMD AEM-7.

Maryland Area Regional Commuter (MARC) also acquired six HHP-8s. The locomotives were for use on its Penn Line between Perryville and Washington, DC.

The locomotives have a 6 MJ crash energy absorbance structure; the carbody is stainless steel. The electrical traction system is directly derived from the system used on Alstom's BB 36000 Astride locomotives; this includes four 1.5MW three phase asynchronous traction motors powered by GTO based inverters, with one inverter per motor; the electric system also allows dynamic and rheostatic braking. The locomotives were designed to FRA Tier 1 standards (up to 125mph operation).

As of 2011 Amtrak operates 15 of the locomotives on the Northeast Corridor on Boston to Washington DC trains; the locomotives have a mileage of approximately 750000 per annum (2009 figure).

In 2002 Amtrak's fleet of 15 units was temporarily withdrawn along with Acela express trains due to cracks in components of the bogies.

The Amtrak locomotives were found to have low reliability; despite attempts to improve reliability, in 2009 the units required unscheduled maintenance on average every 12.6 days. As a result replacement of the fleet at the same time as the older AEM-7 locomotives became actively considered after only 1 decade in service - a large order for a standardise fleet would have price economies, and the resultant fleet have lower overall maintenance costs. A replacement fleet of 70 locomotives starting delivery in 2012 was planned, with HHP-8s kept as a reserve in the short term.