Menu
Home
People
Places
Arts
History
Plants & Animals
Science
Life & Culture
Technology
Reference.org
EMD SD90MAC
open-in-new
<p>The EMD SD90MAC is a model of 6,000 <a href="/facts/Horsepower/jRMwmIxA">hp</a> (4,470 kW) <a href="/facts/AAR_wheel_arrangement/PLWUMWSy">C-C</a> <a href="/facts/Diesel-electric_transmission/0AKK4nsE">diesel-electric</a> locomotive produced by <a href="/facts/Electro-Motive_Diesel/18JmQm6l">General Motors Electro-Motive Division</a> (EMD). It is, with the <a href="/facts/EMD_SD80MAC/UBNgxvct">SD80MAC</a>, one of the largest single-engined locomotives produced by EMD and among the most powerful diesel-electric locomotives, surpassed only by the dual-engined <a href="/facts/EMD_DDA40X/9CGlzzt2">DDA40X</a>. </p><p>The SD9043MAC is the 4,300 <a href="/facts/Horsepower/jRMwmIxA">hp</a> (3,210 kW) variant, using a 16-cylinder <a href="/facts/EMD_710/30nnHyCk">710G engine</a> instead of the <a href="/facts/EMD_265/fdAAwwGP">H-engine</a>, which was originally intended as a temporary alternative while EMD tried to solve the <a href="/facts/EMD_265/fdAAwwGP">H-engine's</a> issues. However, the accompanying upgrade program was never utilized by its customers. </p><p>The SD90MAC's features include <a href="/facts/Radial_steering_truck/Q5060jts">radial steering trucks</a> with <a href="/facts/Alternating_Current/qxICS3xa">AC</a> <a href="/facts/Traction_motor/5xAX9sdk">traction motors</a> and an isolated <a href="/facts/Cab_(locomotive)/JPqnrkoC">safety cab</a> which is mounted on shock absorbers to lessen vibrations in the cab. The SD90MAC, like the SD80MAC, <a href="/facts/EMD_SD70ACe/1Job9a9r">SD70ACe</a>, and <a href="/facts/EMD_SD70M-2/1Job9a9r">SD70M-2</a>, has a wide radiator section, nearly the entire width of the locomotive, which along with their size makes them easy to spot. </p><p>As of 2019, some SD90MACs are still in service on the Union Pacific. Norfolk Southern had rostered 110 SD90MAC locomotives purchased or traded from Union Pacific or the CIT Group respectively, that have now all been rebuilt as <a href="/facts/EMD_SD70ACU/Jh1JwpGd">EMD SD70ACU</a> locomotives. Canadian Pacific has also opted to convert their small fleet of long-stored SD90MACs into SD70ACUs as well. </p>