Difference between revisions of "SD80MAC"

Latest revision as of 21:41, 9 April 2019

CSX #4601 leads a stone train at Grand Rapids, MI

The Electromotive Division SD80MAC is a 6 axle, 5,000 HP diesel electric locomotive built in 1996 for Conrail. It is the longest locomotive produced by EMD to date (along with the SD90MAC, excluding the DDA40X), measuring 80 feet and 2 inches. It was the first EMD locomotive since the SD45-2 to use a 20 cylinder engine, this being a 20 cylinder 710-G3B rated at a whopping 5,000 horsepower. Essentially the units were just big, modern SD45's (both types use 20 cylinder engines and sport flared radiators). They were also the first (and only) locomotives with AC traction ordered by Conrail.

In 1995, Conrail was looking for a high horsepower locomotive that it could put to work on it's hilly ex Boston & Albany line and in coal service. It already rostered modern SD60I's and 8-40CW's, but they needed something more. After inquiring about AC traction SD70MACs, EMD showed Conrail their latest, most powerful single engine locomotive to date: the SD80MAC. Designed as a step between the 4,000 HP SD70MAC and the then still under development 6,000 HP SD90MAC, the SD80MAC used a 20 cylinder 710 engine to develop a middle-of- the-road 5,000 HP. Unlike the SD90MAC, the SD80MAC used no really new technology and relied on the proven 710. It ran on EMD's then new HTCR-II radial self steering truck, which allowed the unit to go around tighter curves than other six axle locomotives of the same or even smaller size, and also greatly improved adhesion. One first for EMD on the SD80MAC was that it used compressed air to start the prime mover, before this units were cranked over electronicly. The SD80MAC was also the first unit to feature an electric parking brake.

Conrail ordered 28 units, numbers 4100-4127. The units were delivered in a special Conrail paint scheme featuring a BN executive style white stripe that wrapped around the nose and cab, along with standard Conrail blue paint with "Radial AC SD80MAC" under the road number and "Conrail Quality" spelled out along the hood. The SD70MACs later aqcuirred by Conrail wore the same scheme. Like nearly all Conrail engines, the SD80MACs featured cab signals and red marker lights on the nose and rear. EMD also built 2 demonstrator SD80MACs, which were later bought by Conrail and became 4128 and 4129 for a grand total of 30 units. An interesting note, Conrail had started to order more of these units but during the acquisition talks with NS and CSX the order was changed to SD70's and SD7 0MAC's with the latter being built to CSX specifications.

After the 1999 Conrail split between CSX and Norfolk Southern, CSX and NS split the 80MAC fleet accordingly, CSX getting 13 and NS getting 17. CSX's were originally numbered 800-812, then being renumbered 4590-4602 in 2007. NS's SD80MACs became NS 7200-7216. Until NS's 2008 order for GE ES44AC's, their SD80MACs were the only AC traction units on the railroad.

It is interesting to note that the Chicago & North Western and the Canadian Pacific both placed orders for SD80MACs. CNW ordered 15 units, but with the UP merger happening at the same time, UP switched the order to SD70M's instead. CP's were canceled as well, and the road later ordered SD4043MACs and 3 SD90MAC-H's.

As of this writing all SD80MAC's have been repainted by CSX and NS, NS #7205 being the final hold out. The number of SD80MACs was reduced by one in 2014 when CSX scrapped 4594 after being heavily damaged in a derailment.

In 2017, CSX traded their 12 remaining SD80MACs for 12 SD40-2s. As of 2019, NS had thoroughly refurbished and repainted all of the former CSX units, bringing all of the 80MACs back under one roof.

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