The thread below about the merits of preserving an SDP-40F reminds us that we are many years removed from the early days of preservation when preservation was somewhat haphazard and the result of some private effort motivated by personal experience or interest or some lucky break.

This leads me to some questions I admit I have no answers for:

I recently looked at my old magazines that described the complexity of modern locomotives, specifically the presence of micro-electronic/computers on the newest AC monsters. I wonder how future generations will fabricate replacements for such locomotives or are they modular in nature and will they just constantly be upgraded throughout their service life.

*If not constantly upgraded, will the specialized components be available to run an AC-4400 or SD-90MAC in 2075? Its one thing to make a new smokebox as has been done for the K-4 at steamtown, its another thing to refabricate an obselete microprocessor.

*If they are to be constantly upgraded, should preservation efforts start when an engine is new, rather than old in order to maintain the as built condition?

*since these engines are strictly freight only, what would the point of operation be? There doesn't seem that there's much interpretive value to attaching a string of coaches behind an engine that was designed and run in a freight-only time by a freight only carrier. W/o riders how would the operating costs be financed.

My personal thoughr is that in the future, we are going to be running only steam and 1t or 2nd generation diesels due to the considerations listed above.

Any thoughts? Especially from the more mechanically oriented folks here?

superheater@beer.com

> *If not constantly upgraded, will the
> specialized components be available to run
> an AC-4400 or SD-90MAC in 2075? Its one
> thing to make a new smokebox as has been
> done for the K-4 at steamtown, its another
> thing to refabricate an obselete
> microprocessor.
>
> My personal thoughr is that in the future,
> we are going to be running only steam and 1t
> or 2nd generation diesels due to the
> considerations listed above.

Good questions - I believe you're right. Once a micro is no longer being produced and the dies are gone, you're out of luck. Try finding a Z8000 nowadays, for instance. Who could afford to restart a production line, especially for just a handful of parts?

Once any spares have been used up, the only possibility would be to replace the original micro with a newer model. IF the embedded code was written in an HOL and IF it is sufficiently portable, it might be possible to recompile for a different platform. Even then, the pinouts would probably be different and you will need a hardware team to design and build new circuit boards. Otherwise, it would be a large-scale software development task to redefine the requirements, develop and test new code, etc. etc.

At a minimum, anyone out there who thinks he will want to not only save but operate one of these microprocessor-equipped Diesels should be contacting the manufacturers NOW to get as much as possible of the design documentation preserved. Reverse engineering a steam locomotive is relatively easy; an embedded system with a fried micro would probably be impossible.

Any way you look at it, it's going to be extremely expensive.

By the way, I do embedded software development for a living, but this is the last thing I'd want to be stuck with at the museum. What kind of a hobby would that be?

I for one am not afraid of obsolete computer parts. My roommate and friend writes software for the Space Shuttle, and essentially what he does is write new computer programs to interface with 1970s-technology hardware.

While it definitely wouldn't be *fun* to do, it could be done.. all you need to know is what the expected funtion (output) of any given circuit is. I'm sure in future "restoration" projects, most of a diesel's computer controlled functions could be run by the future equivalent of a laptop.

Initial Disclaimer

I am not a computer programmer, and therefor may be missing something that would be obvious to one.

And now for our regularly scheduled post. . .

It seems to me that preservation is valid be it static or operational. A dead processor would not prevent static display, and presumbaly one could find a way to bypass such a beast or create new controls to opperate. A parallel would be the MU controls or new airbrake controls on some excursion steamers. These were not original equipment, but facilitate opperation of the locomotive with modern passenger cars, which use different brakes, (thus the new brake handle,) and require head end power for lights and environmental stystems, (which the trubo generator on a steamer just isn't up to, thus the need for an MUed diesel.) Given that numerous aircraft are opperating which would originally have been built with computer equipment which is now obselete, (the Space Shuttle is a good example,) it seems to me that you can update or replace these things. I don't think that the original system architecture is really necessary to valid preservation any more than the original link and pin couplers and lack of air brakes are to 19th century steam opperation. In any case, we'll find out, and whatever the outcome, I think an AC-4400 and an SD-90MAC will be fantastic pieces in somebody's museum one of these days.

Sincerely,
David Ackerman


david_ackerman@yahoo.com

I agree with Wowak that if you know that the outputs for microcontrol system is, you could replace it with an off-the shelf industrial control system or perhaps a regular (for 2075) PC. The software could be custom written for it; the whole setup would not be frowned upon any more than replacing a diesel engine with a more modern unit. This upgrading of control systems happens all the time in chemical plants and factories; as long as the outputs are documented.

However, I think the problem will not be the electronics, but the electrics. Look at the GG-1; none of which are operable because running them will involve ripping out the electrics and replacing them (and the environmental problems involved.) Unless off-the shelf tyristors, alternators, and similiar equipment are still available, I think these will not be cost-effective to replace. While transit equipment appears to easily fall in the relm of restoration these days; you see few freight motors that are still operable.

One thing that AC locomotives are legendary for are the incrediblely slow speeds at which they can run without burning up their traction motors. I would thing that some kind of "tractor pull" setup that demonstrates their lugging ability would be impressive to museum onlookers. You wouldn't have to run it that far, either.

-James Hefner
Hebrews 10:20a

Surviving World Steam Locomotives
james1@pernet.net

More often than not, there are work-arounds.

For instance, I tinker with vacuum-tube gizmos of one kind or another. Fortunately for us retro-techies, vacuum-tubes are still being made in places like Russia and China, but sometimes the modern examples are pricey. So, we cheat. Instead of using a 5U4 rectifier tube, use 2 each 1N4007 diodes in series with a modest (200 ohm) resistor to simulate one side of a 5U4, and the same lashup for the other side. Yes, it isn't "hollow-state", but the electronics "downstream" from such an ersatz "5U4" won't care-- the circuit will work just fine.

Much the same argument can be made for computer electronics-- who cares what's inside the "black box" as long as the inputs produce the correct outputs?

Hale Adams
Ex-Conrail General Car Foreman
Elkhart Yard, 1989-90

ahadams1@ix.netcom.com

May I also suggest that someone who ends up with a locomotive with some kind of pc boards or programmable controller should immediately buy any and all available backup parts. I keep a couple of Compaq Deskpro 386 machines around here so I can still grab somebody's old 5 1/4" floppy program.

Erie Lackawanna Dining Car Preservation Society
tstuy@eldcps.org

And we are not just talking about just Diesel-electric locomotives. The Western Railway Museum has just taken on a MUNI Boeing-Vertol Light Rail Vehicle from 1979. The intention is to run it, but time will tell if it is possible without a supply of circut boards which are impossible to replace.

Guess electricity is just one of those short lived fads that will come and go....

ted_miles@nps.gov