That more than answers the question and I learned a lot when it comes to towers and sand operations in general. Thank you.
I don't know about the hose retracting - I think more common is the arm that supports the hose is spring loaded so when not actively pulled down to the sand filler, it pulls back up far enough to clear any equiment running past, but within reach of the hostler to pull down to fill the next loco. There is the rubber hose, the part you have in black which is the attachment point/handle, and then the nozzle which you have in blue that moves inside the handle part to act as a valve to start and stop the flow of sand. I'm going by the description of the components from the manufacturer link I posted, they aren't the only company who makes this equipment and others may function slightly different.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
If I understand correctly then, the blue part is what the engineer or whoever is filling takes the nozzle, attached to a hose (I presume), and inserts the nozzle into the sandbox hatch and the system automatically fills until the box is full. Then when done the hose is retracted into the pipe.
From this explanation: http://www.monroeeng.com/me_noz.htm
it seems that the nozzles are self-closing. The operator presses the blue part into the sandbox opening which starts the flow of snad, when it is pulled out, the sand shuts off.
I am planning to bash a sanding tower to fit a spot in a service yard I have using a hopper car as a base. In looking at parts from other sanding towers, the nozzles from the tanks have an unusual end on them. (Rough diagram here) What exactly would the prototype use the area in light blue used for?
Any help the forums can provide would be welcomed.