Hi everybody,
I will now write about the variations of the Atlas E8 diesels for those who
may be interested (anybody?). I will divide the discussion into headings based
on the different parts.
BODY (Santa Fe only)
The earliest units have a different silver color than later units. It is a
duller, almost greener silver than the later carbodies. This is apparent when
placing the two variations side by side.
I have found four variations in the red used also. There is a bright
semi-gloss, a bright flat, a darker semi-gloss, and a darker flat. I believe that the
bright semi-gloss was only on the earliest units because my original E8 that I
bought in 1967 (box insert date - 9-67) has this finish whereas the one I
bought in 1969 (box insert date - 1-69) has the darker flat finish. I have seen
the latter three variations intermixed on units from 1968 - 1969.
There are variations in the brightness and opacity of the yellow Santa Fe
herald on the nose. This ranges from a very bright and opaque yellow to a very
dark and almost see-through yellow. I have also seen the registration between
the yellow and the black lines being off.
BODY (Remaining Road names)
I haven't seen any appreciable differences in these units.
FRAME
I haven't seen any appreciable differences here either except for the
"Zamacitis" that some suffer from where the casting cracks and swells and, if bad
enough, crumbles when handled. The swelling can be bad enough to where the frame
will get stuck in the body or even push out and crack the carbody casting!
The parts, other than the motor, mounted to the frame (light bulb, front
contact plate and wire) seem to have remained consistent throughout the
manufacture period.
Dallas Mallerich, in the Greenberg guide, indicates that some frames
(chassis) had only two motor mounting holes drilled diagonally instead of all four
holes but I have never seen any like this (although I have seen it with C-Liner
frames). Also, it is difficult to tell if the holes are actually drilled or
merely cast into the frame.
To me, it looks like they were cast.
FRONT TRUCK
The earliest units have the wheels merely rotating on the axles that make
contact with the phenolic contact plate with no springs.
Next came mounting a different wheel on a different axle with a shoulder on
it and a coil spring between them to maintain pressure between the wheel and
axle for better electrical continuity.
The latest is the sprung wheel/axle in conjunction with auxiliary contacts
mounted on the truck frame. These contacts are sprung shoes that make direct
contact with the rail for the ultimate in current pickup! The truck frames were
changed for this also with holes to make room for the barrel of the contacts.
Thus, you can't add the auxiliary contacts to older frames (a major
disappointment when I was a young lad).
As an aside, it is easily apparent that an effort was made during the
manufacture of these units to improve the electrical pickup of the front truck
because, after all, this is the only place where pickup is taking place! There may
be some incidental pickup on the ground side of the rear truck through the
wheels, gears, motor shaft, and motor can when one-side insulated axles were used.
More on this next. It was a fairly major frustration with the earliest
versions to keep pickup effective because it didn't take long for dirt to get
between the contact surfaces of the wheels and axles and a stuttering E8 was the
result!
REAR TRUCK
The earliest units have only one side of the wheelset insulated from the axle
and, as a result, there was some pickup from the ground side of the truck.
Not that it is reliable pickup what with all the parts current has to flow
through and grease or oil on the motor bearings. These had to be oriented
correctly, also, or a short would result. Later units have both wheels insulated so the
orientation doesn't matter. Of course, any current conduction is lost too.
Earlier units have straight-cut gears on the driven axles and idler gear. The
gear teeth are parallel to the axle. Later units have helical-cut gears. the
gear teeth are at an angle to the axle. This is apparent upon close scrutiny.
This was done for better mesh with the worm, I'm sure.
The earliest units have the rear truck retained with a snap ring and washer
mounted in the groove at the end of the motor worm. Later units use a copper
retainer plate fastened to the truck with the front screw and sliding into the
groove on the end of the worm. When I say earlier and later, it's relative
because I don't think it took too long before Rivarossi went with the retainer
plate method. Probably way too many complaints about lost snap rings from
customers and dealers!
There are some variations regarding traction tire placement too. It seems
that most of these units have the tires on the right side of the locomotive on
the two driving axles. Of course if one-side insulated axles are used, it would
dictate that the traction tires be on the right side to avoid a short,
assuming the traction tire side is the insulated side. There are, however, some units
with the tires on the left side of the locomotive and some with the tires on
either side of the middle axle. These, of course, would be mounted on axles
insulated on both ends. Dallas Mallerich indicates, again in the Greenberg
guide, that some have tires on all the wheels of the power truck but I have never
seen any like this.
MOTOR
The famous (or infamous) Rivarossi can motor comes in colors! (sort of). The
earliest ones are black (presumably so they can't be seen easily) and the
later ones are one of two different colors of silver. Some have an almost
stainless steel look to them and others have a more aluminum look.
The black motor cap has a mold number (1,2,3, or 4) and ITALY molded into one
side and Rivarossi molded into the other side (both on the top of the cap).
Sometimes the Rivarossi is on the right side when the motor is mounted and
sometimes it's on the left. This doesn't matter as long as the motor can is
oriented properly. There are two notches in the can into which the cap fits. These
end up being at the front and rear of the motor mounting. One notch has a flat
bottom and the other has a vee shaped bottom. The vee shaped notch MUST be at
the ground end where the ground contact and brush attach (the rear end, in
this case). If it's oriented incorrectly, the locomotive will go the wrong way
for a given polarity on the track.
Some of the brush holders have rounded heads on them and some (most) have
flat heads with a groove included near the end.
Sometimes the right rear and left front frame holes were used to mount the
motor with screws and sometimes the right front and left rear; never all four,
although that may have been the original intent being that there are four
holes.
Inside the motor, there is a variation in the commutator form. In the earlier
units, the form is a little less substantial with only the slots in the
flanges to keep the commutator segments in alignment. The later units have flanges
that are a little thicker and there are grooves in the flange at the shaft end
to keep the tabs of the commutator segment in place. This change was no doubt
due to the tendency of the commutator forms on the earlier units to crack or
to cook and melt down from heat.
Um, there were also different colors of wire used for the armature windings
(OK getting a little too nutso).
Dallas makes mention of a variation in the worm in that some have a flat edge
and some have a beveled edge. I'm not really clear as to what he's referring
here whether it's the edge toward the motor or the edge toward the end with
the shaft and groove. I have seen only one type, however (beveled at the shaft
end).
Well, that's all I can think of. If anybody notices anything else that's
different from what I have stated, feel free to notify us.
Also, any reference I have made to Dallas and his observations in the
Greenberg guide are strictly for comparative purposes only and not to disagree with
or otherwise reduce the importance of his work. His efforts in writing the
Greenberg guide and compiling the information contained therein was monumental,
especially considering his age at the time (17).
Regards,
Doug
