Humpback ALCO's?

@CALNNC posted:

Was there some kind of plastic or manufacturing defect in the Lionel 2023 and similar series of ALCO diesels where they get a hump between the cab top and the fan?  I found some flat and some bulging, a couple that looked like it was about to pull the roof from the sides.  Is that motor heat causing that?

I recall reading posts about this condition and it is heat related causing the shell to warp.

So this not only happened to alco series shells.

I recently acquired this beast of a Western Pacific F3 with that symptom. The sides of the shell do not lie flat perfectly on the chassis. This shell distortion is noticeable.

I also have a Boston and Maine postwar GP 7 loco that doesn’t lay perfectly flat on the shell. It’s wasn’t noticeable until the screw holes did not line up! I laid it on an absolutely flat surface and it rocked up and down.

heat for decades of great continuous running probably contributed.

@Rich Wiemann posted:

Yes motor heat related.

Then why would the dummy A be also affected?  It was a problem related to the molding process.  Lionel modified the dies in 1953 with a small saucer shape added to the roof in the middle of the front "hatch" to eliminate the warping.

Rusty

@Rusty Traque posted:

Then why would the dummy A be also affected?

On mine, it's because I switched the shells at some point over the last 55 or so years. Probably more than once.

@ADCX Rob posted:

On mine, it's because I switched the shells at some point over the last 55 or so years. Probably more than once.

Every one of the early Alco's I've seen have been affected by the hump on both units.  I've never observed one without the hump, although the degree of hump varies.  When I was hot 'n heavy into Postwar, I passed on a lot of 2023's until I found one with a minimal hump.

I seriously doubt every single owner of these locomotives swapped shells over the years or ran them for hours on end.

Rusty

One way to prevent this is line the interior of the shells with aluminum foil. Its cheap and is s good heat sink.

Its not always heat related.  Most all is related to defects in the mold design creating stress in the original shell when it was molded.  Over time these stresses cause the shell to develop the "hump back" look.  The F3's are also prone to it.  One has to remember that the molding of plastic for this large of a train shell was in its infancy at that time, so Lionel was learning as was everybody else.  Up to that time, most things were diecast metal or Bakelite.  Some shells have more hump that others, some are nearly dead flat or as it should be shaped.  The heat from the motor in the smaller Alco shell might have sped up the process of the plastic "relaxing" its stress points from the molding process faster, hence more of them with the issue over the F3's  AD

Alum. foil will do the trick did that for years,

It's not heat related, It is caused by the instability of the early plastics. Or the F-3's would have a double bulge on the roofs. Where it bulges is where the ejecting sprue is.

@prrhorseshoecurve posted:

One way to prevent this is line the interior of the shells with aluminum foil. Its cheap and is s good heat sink.

What do you use to get the aluminum foil to stay stuck to the roof? Thx.

The AMT F-type Diesels had the same issue. Both powered and non-powered units. No heat in the dummies. The Kusan versions had no hump, regardless of powering.