Re: k-27 453's doghouse

Where did the front end brakeman spend his time on duty before doghouses were invented? What function did he perform after air brakes were installed? And why did D&RGW put doghouses on tenders if there were no actual duties for the head end brakeman to perform. And why didn't he ride in the caboose? And what function did those pipes and handle in the doghouse serve?
And thanks Randy for posting 453s' fine doghouse restoration.
The above questions have been rattleing around in my brain since early on in my railroading experience and I would appreciate laying them to rest.

George