[Leica] Train

[sdp35 at cwazy.co.uk (Craig Zeni)]

On Apr 1, 2005, at 12:57 PM, jon.stanton@comcast.net wrote:

>       "Wow!  They really were grinding the rails.  Before I looked I 
> thought I might see something really rare these days, a hot box.  
> Thanks Lee"
>  Back in the early 70's I worked for a company that made grain hoppers 
> and "slurry' cars....On occasion we would service cars that had "hot 
> boxes" aka blown bearings. Timken put an end to that genre of car. 
> Back then a car had to be "retired" if it was 50 years old even if the 
> "trucks" (wheels) could be upgraded...question is...when was the last 
> "hot box" car made?

Those were 'solid' bearings, ie, not roller bearings.  They were big 
brass solid sleeve bearing lubricated with oil that was soaked into 
'waste' - basically cotton rags stuffed in the bearing journal boxes.  
If the oil wasn't replenished, or if the bearing was simply worn, the 
bearing would overheat and run hot...in extreme cases the axle would 
wear thru the bearing and then weld itself to the truck.  Typical 
result there was that the axle would break and everything would go 
splat in a derailment.  Roller bearings have made this sort of failure 
very rare now.  Solid bearings were banned from interchange service (ie 
when one railroad passes a car to a connecting railroad for forwarding 
on) since sometime in the later 1980s.  And the 50 year rule is now the 
40 year rule if I'm not mistaken...

CZ
Traingeek, NC