Toward the end of the page on the link below are three photos of end door boxcars. In these examples, fire engines are being unloaded out the end of the car.
In turn, the link above references this link below, with another end door boxcar unloading scene and a side view of a PRR Class X-30, No. 59861:
At the end of this second link is a great story about the wreck of a PRR boxcar carrying a fire truck.