How Things Work on Railroads: Tunnel Radios

Описание: For over 100 years helper engines required crews to operate them. In the 1980s the railroads got rid of cabooses (much to the chagrin of conductors and rear brakemen), replacing them with remote End Of Train Devices and they also began experimenting with remote helpers controlled from the lead unit but spotty radio signals caused a lot of problems including derailments caused by loss of communication with helpers and one of the real trouble spots was tunnels.
In the 1990s radio technology had progressed to the point that remote controlled helpers became viable (much to the chagrin of the crews who once operated them) and within a couple of years were the norm. I still find myself wanting to wave at them!
In the intervening years radio technology has progressed even more and issues with remote helpers, or Distributed Power Units, are virtually nonexistent.
I was asked to do this piece by a subscriber so I did some research and this is what I came up with. I hope you enjoy it!
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