They just don't know when to stop, do they? Fortunately for us, of course........

https://www.irm.org/in-the-news/sd70mac ... ed-by-irm/





Not noted in the above was that it was delivered in BN "Grinstead" or "Executive" green with wide white stripe.

The UP is dropping this loco off, as well as the 2 former Amtrak engines, as I type this.

Long may they slowly add to the iron content of McHenry County soil!

Jeff

This unit still has stainless steel handrails on the pilot under the paint, from the time when the BN president was using it on office car specials. Speaking of which, I recall the paint scheme these units were delivered in being called appropriate for a jar of hand cream, not a locomotive, I believe the guy at that time was from an airline. Trains magazine called these the best locomotives on the market back then, the main problem IRM will likely have will be with the early-90s electronics. Christian James photo, click to expand.

The first SD70MAC that we got on the Denver Division was delivered one week before BN paid me a year's wages to resign. Nobody knew anything about it, so it sat for that whole time on our pit track at the 23rd St roundhouse in Denver. The only thing we DID know about was the orange button on the floor under the control console, which would blow a furious rendition of the grade crossing signal over and over when somebody stepped on it, and it wouldn't stop until somebody stepped on it again. We had great fun setting it off just before shift change, then covering our ears as we'd run toward the parking lot....

I wonder if this one still has the desktop controls, which everyone hated, this may be the first unit at IRM that has them.

Well, old timers like me much preferred the traditional cab arrangement, especially guys that did a lot of switching, but many if not all the guys in the coal pool liked the new cabs very much.

So far as the electrical end goes, I liked the DC locomotives better because at low speeds with no train behind you, you could throw them in reverse and crack the throttle if you got in trouble, and needed to stop faster than you could with air brakes. I saved four guys from being killed during my thirteen year career by doing that. As most of you know, AC locomotives just unload if you plug them, and keep right on rolling.

Acquiring modern equipment will be both a blessing and a curse for IRM. I'm afraid that many of the more modern additions, both diesel and electric will become static displays because of the intricate computer software and hardware that will be hard (and perhaps very expensive) to repair/replace. This goes for 9400 as well as any new rapid transit cars. Gone are the days perhaps of using hand tools to repair equipment. Let's hope IRM gets additional modern equipment, but also acquires spare circuitry to make the things work.
Bob M

Support for obsolete electronics will be a steadily increasing challenge into the future. Unfortunately it has been largely ignored by industry organizations, at least so far....

PC

Speaking of old equipment since I did a bit of work on the electornics and software on some of these SD70MACs. Was this one upgraded to FIRE with CCB2 or does it have ICE with CCB1 and early ECP airbrake equipment onboard? It would certainly be neat if this locomotive is equipped with NYAB CCBI and the Rockwell ICE control system. That in itself is getting rare, harder to maintain but yet I get mildly happy seeing them when I climb aboard. T

I know for a variety of reasons (waveform control in AC?) that electronics are almost essential in modern locomotives, but at my former gym, the maintenance guy was a retired Penn Central/Conrail locomotive mechanic at Enola.

He told me how in the early days -he started at the end of squiggly worms, when first gen stuff was still around, if there was a problem, they'd get the system blueprints, and with some experience, could usually trace the likely issue-and could replace a wire or relay-and that because of the lack of miniaturization, you could often see damage.

He also told me that when the later stuff started coming in with "cards" (I think that's what he called them) maintenance often involved having a much rougher idea of what might be causing the issue (and couldn't see the damage) and so they would often have to resort to trial and error. When the unit ran, yeehaw-we found the defect, only to have the same unit come in months later repeatedly with the same issue-and then they realized after multiple replacements that it wasn't just a defective card, but something else causing the failure-and that was much harder to identify given the complexity of things and the reliance on modular, sealed components.

Of course, gym treadmills have electronics as well. If the control unit crapped out - you might be able to order a new control unit, but are you really going to spend $500 on a treadmill that's been subject to commercial use or just buy a new treadmill?

The more likely it is that repair doesn't make commercial sense, the less likely there's going to be replacement components from the vendor.

This doesn't even begin to consider the economics of a diminishing install base, the dissolution or acquisition of a vendor and the loss of technical knowledge through time.

Electronics are like money- a wonderful servant and A fearsome master.

However, we have commercial planes flying with floppy disks and Windows 95 (not even 98SE?) and despite all our wizardry, still can't stop a pilot from engaging the fuel cutoff switch on takeoff.


https://arstechnica.com/information-tec ... -overhaul/


https://yourstory.com/2025/05/planes-us ... -explained

LIke the John Bull, it will eventually become an obsolete, static display, so get your operating photos and videos while you can.

The major difference--as demonstrated in 1981 by Jack White, Bill Withuhn, and others--is that if you are WILLING to take the chances of firing up the John Bull or other old steam loco (springing leaks, breaking things or worse), you absolutely CAN, quite easily. It's debatable (and will be for a while) whether it would be possible on the newest-museum-arrival diesel and/or electric locomotives to either replace complex computer commands and electronic controls or circuitry in kind, or conjure a way to bypass them completely and still make it move under its own power. Similar debate has raged for ages on whether this could be done on a far simpler PRR GG1--and we haven't seen anyone rise up to the challenge yet, largely because you'd need new transformers or replacements just to even start.

Just this morning on a forum for 1990s car models, someone was raising the question of whether they absolutely had to replace the PCM (Powertrain Control Module, or "onboard computer") on his car, or bypass it and just run it. The consensus was that it could be made to run around a track or parking lot a few times, but it would never be suitable for a road trip, would eventually ruin the engine, and would never be "street legal" or pass emissions inspection where applicable, so go get a replacement PCM and reprogram it (which it mostly does automatically anyways). Hmmm, sounds like "running for Diesel Days" at the museum, doesn't it?

Are the Progress Rail/EMD 9500-series Siemens SD60MAC’s still sitting around somewhere? Lagrange or Pueblo maybe? A few years back I think 9503 was still the most intact in Pueblo? Seems like at least one should be saved as notable for AC traction, but if the electronics are outdated and can’t be replaced, what’s the point? Off the top of my head, where else but at IRM could you really run anything that big on a mainline anyway?

https://www.flickr.com/photos/barrigerl ... 0320647903

PC

That is part of the CCA control system on an evolution series locomotive GE/Wabtec locomotive. Still very much in production to the point that you can still buy a brand new locomotive with this control system.

I’d still love to know the control system and electronic airbrake on the 9400 if anyone knows. I know what it was built with but I also know BNSF was heavily updating these to FIRE and CCB2.