The
SD70ACe is the successor to the older SD70MAC. Built from 2004 to
2014 in the United States, the SD70ACe was originally designed to
comply with EPA Tier 2 locomotive emissions regulations. Beginning
in 2012, newly built SD70ACes were EPA Tier 3 compliant. SD70ACes
are equipped with EMDs 16-710-G3C-T2 prime mover, rated at
4,300 horsepower (3,200 kW). Later Tier 3 models are rated at 4,500
horsepower (3,400 kW). They are rated at 157,000 lbf (700 kN) continuous
tractive effort (191,000 lbf (850 kN) starting). Braking effort
is rated at 106,000 lbf (470 kN). Although mechanically similar
to earlier SD70 units, the SD70ACe rides on a new underframe and
uses mostly new sheet metal above the frame. Electrical cables and
air lines have been routed beneath the walkways on opposite sides,
allowing easier access for maintenance. Continuing the designs of
the SD80 and SD90 series, the radiator on the locomotive is nearly
as wide as the cab, the center hood section is a step down below
the roofline, and the dynamic brakes have been moved to the rear
of the hood. The SD70ACe uses the cab design of late-model SD90MAC-H
units, which uses rectangular window glass and is externally different
from the two cab variations used on earlier SD70M and SD70MAC units.
In 2008, EMD standardized the isolated cab on subsequent SD70ACes
after non-isolated cab units were restricted from leading on BNSF
Railway due to excessive cab vibration. Purchasers included ArcelorMittal,
BNSF Railway, Canadian National Railway, CSX Transportation, Ferromex,
Kansas City Southern Railway, Montana Rail Link, Norfolk Southern
Railway, CVG Ferrominera Orinoco, Union Pacific Railroad, Quebec
North Shore and Labrador Railway, BHP Billiton, and shortline Arkansas
and Missouri Railroad. |