Topic that arose with a discussion with an electronics-module friend of mine:

Have any preservationists had yet to deal with the issues of modular electronics, controls, and wiring similar to the ones that made the "Dash Two" EMD models what they were? Have there been operating "preserved" locomotives, aside from the semi-preserved F40PH's, business-train locos, and maybe UP 6946, that incorporate these modules?

Having several vintage oscilloscopes and signal analyzers in my living room at the moment (salvaged on behalf of an estate--anyone want a Tektronix Type 564 oscilloscope?), I'm keenly aware of the massive steps in electronics and hardware that have occurred over time. I've also seen a room-sized load of electronics in one locomotive reduced to a suitcase-sized module in a rebuild. What I shudder to think is that there may come a day when diesel or electric locomotive restoration may be impossible without an advanced electrical engineering degree.

I once took a look at some EMD electronics from the late 1980s, and I was mostly not impressed with what I saw. It looks intimidating, but it seemed to me to be just simple microprocessor based stuff about five years behind what the rest of the industry was doing. So when one of these modules breaks down, repairing one would be on the same level as repairing a disused home computer stuck way back in the closet - maybe a Commodore 64 or something. A logic probe and simple scope and DMM will cover almost all the bases.

The thing to do when a rail museum needs to repair a control system from a SD40-2 or similar is to look and learn outside the museum. There are plenty of people that have the knowledge to repair these things. On this forum, we moan about how young people are not into steam locomotives. Other forums, like for ham radio, have the same complaint.

Guess where the kids with a eye for old technology are going?

The so-called "vintage computer" or "retrocomputing" field is growing at a huge rate, and many of the guys interested are very hands-on. Getting a sick SD40-2 healthy might prove to be a lot of fun, and frankly, probably not much of a challenge.

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Will

Additional thought...

Since the control systems in "modern" locomotives really are computers, we must think of both the hardware AND the software, if we plan on maintaining these machines. The hardware generally does not just disappear, but software has the annoying tendency to slip away. And without software, hardware is cold and dead.

The early computer museums, back in the 1980s, made the mistake of collecting and preserving hardware and documentation and mostly neglected the software. Now, there are HUGE holes in pre-1970 computer history, due to this neglect. Now we are scrambling to find what is left before it fades away. And when software degrades, it is lost forever, unless you can find duplicate (more like triplicate) sources to rebuild from. It really is a race against time.

So, my advice to any museums with early computer controlled locomotives is to read out the software from the memory ("do a dump of the ROMs") and archive it safely, offsite. Eventually all memory ICs suffer bit rot, where bits will corrupt on their own, and the Dash-2 electronics is getting to the age where it could start happening.

And one flipped bit can ruin your whole day.

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Will

Don't forget that this problem applies equally, if not more so, to later generations of transit cars. If your trolley museum figures on preserving a 1970s or later LRV, then you'd better start way ahead to stock up on all the varieties of printed circuit boards, chips for them, test fixtures, and programming aids. If you ever plan on operating such a car, you'll need every bit of that hardware and its accompanying software.

I recently had occasion to examine all the complexity of the SEPTA Kawasaki cars built in the early 1980s. In short, OMG! There must be 50 different circuit boards between all the various subsystems. Not only is there complexity, there is the looming issue of obsolescence. You can still buy relays designed in the 1930s to 1950s, but try finding some chips from the 1980s. Good luck.

Short of having all that hardware and the technical savvy to deal with it, you should then plan a nice out of the way spot for your preserved LRV so that it can serve the function of a static exhibit.

Look harder - the stuff is out there, more than you think. There are really very few semiconductors that are unobtainable. Extremely early logic devices are one (not a problem for us), and maybe modern gate arrays and programmable stuff (a bit of a problem possibly, so yes, stock up or emulate with a modern part), although I doubt many are used due to the very low numbers of production runs for railroad stuff.

The thing to do is ASK beyond this forum.

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Will

I work roughly 100 feet from the area where those relays are assembled (The relays that EMD, and others, still use).

As for software, unless the Dash-Two in question has been upgraded with an aftermarket computer, I don't believe you will find ANY software in its electrical cabinet at all. EMD began using microprocessors in the 60 series.

Jeff

In thinking, the boards I saw were probably SD60 - it was just about the time they were being first produced.

So basically, railroad electronics is maybe even further behind the rest of the world. Good for us.

"Software" would include any thing that can be programmed - small ROMs, programmable logic devices, etc. - things that may exist even if there is no microprocessor in the system.

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Will

FYI, new and UTEX Dash-2 modules are still available, as are 50 series modules.

On the dark side, GE used to stock at least some of the Blue Faced Cards as applied to the Alco Century units and U-series. DIY repair could be an option, as troubleshooting instructions are out there and many of the components can be sourced from a good electronics wholesaler. Simple point to point wiring.

The same may not be said for the Dash-7 cards. These are PCB based, and make liberal use of simple digital logic devices. The rub is whether or not the builder ever released card-specific troubleshooting instructions.

Nonetheless, these earlier locos still contain some proprietary electrical equipment
(particularly reactors that measure high current and voltage) that will prove to be unavailable over time.

It was the SD-60 that was equipped with the first generation EM-2000 microprocessor based controls. This generation of equipment is filled with devices that are completely proprietary-meant to be either UTEX'ed or replaced outright.

DPK

What dark side? Unless the stuff is made of undocumented custom silicon, there is no dark side.

And I really doubt there is much, or any, custom silicon. It just would not make sense for EMD or GE to do so, with the small production runs they did for the locomotives.

Weird reactors and transformers? No worry - rewinding them in easy, if a little tedious.

As far as the microprocessor stuff - you say "filled with devices that are completely proprietary-meant to be either UTEX'ed or replaced outright". Unless this equipment is true custom silicon (which I really doubt), it can be repaired by the right people. YOU may not be able to do it, being scared away by the funny looking numbers, but OTHERS probably will not be. Keep in mind that some of these others get old mainframe computers running again - and just how much more complexity is in one of those? SD60 electronics? Childs play...

I hope that I will not again sense that railroad preservationists are more willing to punt when faced with an electrical problem that can not be solved with Home Depots electrical aisle, than to take the easy, more proper solution that lies just out of grasp, but can be reached just by asking.

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Will

Who knows? There could be a retro-electronics expert out there who would be glad to help solve modern-locomotive troubles if offered an hour or two of at the "throttle" of the unit he helped repair.

You have the right idea!

It seems to me that most engineering schools in the US have a model railroad club (MIT being the best known of the bunch). A good place to start looking? Yes!

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Will