Kevin S. Wrote:
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> Not being an expert, or knowledgable at all about
> this sort of thing, but very curious, if a new
> narrow gauge replica could be built, using modern
> materials, desings, etc. - in other words, a
> cosmetic replica, how much longer would it hold up
> given proper care, maintenance, and operated
> properly and safely compared to a restored
> antique?
>
> I realize fully that things like boiler
> inspections, boiler overhauls, etc. are going to
> have to be done routinely according to the rules
> governing such things, but would the rest of the
> locomotive hold up better, thus reducing overall
> repair and operating costs, if it were new, built
> from the latest materials and modern designs?
>
> Would the expense of the new replica result in a
> savings in maintenance costs and lost revenue from
> lost operating days over a period of time?
>
> Obviously, when steam locomotives were the only
> source of motive power and all the required parts,
> or at least a large number of them, were off the
> shelf type items, the answer to this question was
> yes. After so many rebuilds, the locomotives were
> scrapped and replaced. But does that hold true to
> day?
>
> Would a replica of C&S #70 with a cast frame,
> roller bearings, modern boiler, all modern
> materials, and a replica of an Argentine Central
> Shay with the same, etc. pay for themselves over a
> period of several operating seasons and be a
> better investment of taxpayer dollars?
GTL’s #12 has a modern boiler (albeit built to ASME standards, not to FRA standards) which was down this season with a crack in the firebox. Any new locomotive would be just as susceptible to having a blown off cylinder head due to a slug of water as the #12 just was.
Machinery wise, a new locomotive would be equal or better than the best overhaul or restoration, but after a few months of seven days per week full power operation, the same maintenance issues that a restored antique engine has would start cropping up.
The advantage of a new replica would be somewhat lower cost over the very long term. You would be starting off with zero thickness lost to corrosion on the boiler, so it would be that much longer until sheets would need to be replaced. You would be starting with new diameters on all the moving parts, so it would be that much longer until say, and axle needed to be replaced for being undersized.
Back in the day, steam engines weren’t scrapped after so many overhauls, but rather when they weren’t of any further use due to being too small to haul the needed trains. Were there was a niche, steam engines had very long lives, such as #268 in Gunnison, or the Wabash 2-6-0's, around 70 years old and still working due to light rail precluding the use of larger power.
The idea of using roller bearings on replicas keeps coming up, but in my opinion has no merit for two reasons:
First, the first cost would be astronomical, designing around available bearings and making them weather tight in a steam locomotive environment would be difficult, and the costs of a failed design frightening. GSMR converted a steam locomotive to roller bearing driving axles a few years ago, and they were so successful, they converted it back to friction bearings after about two seasons.
Second, defective friction bearings can be nursed along to get through a day, and often repaired with hand tools. Defective roller bearings fail catastrophically, and are only repairable by replacement. To replace a driving axle bearing requires that the wheel be pressed off the axle. Note that even on diesels, the bearings where the traction motors ride on the axles are Babbitt friction bearings.
Third, what is the recourse after x number of years in the future, a new roller bearing is needed, only to find it is no longer available? I recall that the N&W #611's roller bearings were in questionable condition. In checking with Timken, they learned that not only were the bearings no longer available, Timken didn't even have the equipment needed to make those bearings any more. The NS steam program shop foreman told me, "If there is ever a mechanical reason that #611 will need to be perminantly retired, it will be because of a roller bearing failure."
Edited 2 time(s). Last edit at 09/14/2007 08:58AM by Kelly Anderson.
