Do a search on the SD50 and you will find exactly what I said about them in several places. (Here is one https://www.wvncrails.org/sd50-farewell.html) It may have been a negotiated cancellation but it was clear CS didn't want them. My uncle worked for the Rio Grande in train service at the time and I remember him telling me that they wanted tunnel motors and why would they want units that failed back east going up/down South Boulder canyon and at above 10k feet, but they had just acquired trackage rights to Kansas City as part of the MP/UP merger and they needed extra units.

Isn't that story exactly WHY it would make sense to have one preserved.

Nobody disputes that the SD50 had a rough introduction.

But if CSX did this deal to get out of buying those 17 SD50's, then why did CSX turn around the next year and order 20 of them for a late 1985 delivery, lol? Your claim falls apart with that fact.

And Rio Grande changed course away from more Tunnel Motors because they were impressed with the four Seaboard units that they borrowed for evaluation in March of 1984, with the four demonstrators successfully carrying upwards of as much as twice the tonnage as their SD40T-2's.

So they sought to change their order and were told the SD50 production line was booked solid into 1985, so they negotiated this deal since they needed power quickly and there was a traffic slump at the time out East. By doing this, they got them in August/September of 1984 instead of well into 1985.

It was their 10 unit order of SD60's that was the straw that broke the camel's back at CSX, after a rough start with lots of teething troubles with the SD50 had left management without much patience for going through a similar debugging period before getting units with all the kinks worked out of them.

Sadly, while less severe, these too had some early issues and that was it.

Back when the SD50's were new, we got to tour C&O's Huntington shops. There were a lot of relatively new SD50's in there and I noted it to our guide. He noted they had been "under engineered."

In that same era a friend had an Oldsmobile with a 350 cid V-8 diesel. That, it turned our, was also "under engineered," although he got over 90,000 miles before it failed.

I believe EMD's reliability is intertwined with GM's automotive reliability at that time and with GM's parallel decline in automotive market share.

Phil Mulligan

Spot on.

While GM denied this, the Olds diesel was essentially a converted gasoline engine, being based off the 350 V8. GM did not change the head bolt pattern or use stronger bolts to compensate for the additional force produced by a diesel engine, which led to bolts breaking or pulling out of the block and head gasket failures. Years later, Navistar and Ford would have the same problem with the 6.0 PowerStroke engine.

The original 645F engine used in the SD50 was uprated to 3500 HP in an attempt to compete with contemporary GE units. This turned out to cause a lot of problems with harmonic vibration, which led to regular failures of multiple large internal parts (crankshaft, connecting rod, pistons, take your pick). And if this weren't enough, the SD50 also had a brand new electrical system, and was the first EMD model with a microprocessor-based control system. All this was rushed into production without adequate testing, and the bugs ended up showing themselves out on the road.

EMD managed to work out many of the problems eventually, the latest version of the 16-645F engine (as used in the MP36 and some overseas models) runs reliably at 950 RPM and 3600 HP, and the computer eventually evolved into the EM2000 system that was used with great success in the SD70 series models.