Coaling Tower?

For what were these old coaling towersfor?
Did they fill the steam engines with coal?
But why did they sometimes stay far away from a engine yard, where the steam engine were maintained and filled with water?
(Search on railpictures.net for 'coaling' and you will find more of these, standing somewhere in the landscape for away from a yard)

This must be the coaling tower from above.
It stands alone above the mainline tracks, no yard or water tower visible?

It's strange for me as a european, because our steam engines where maintained und filled in the enigne yards (Betriebswerk)

(I also know that the fast long distance passenger trains was filled up under way with water (on a special track , with a special construction on the tender), but i never heard, that they stop somewhere in the nowhere to fill the coal up.)

Greets

Many railroads had coaling stations which straddled the mainline tracks. They were located outside of yards because the locomotives would cover more than a single operating division and would re-fuel en route. Water and sand were also available at these stations.

On some railroads such as the New York Central, the use of track pans to supply water allowed the railroad to boost the capacity of the coal bunker in the tender. Some NYC passenger locomotives worked straight through between Harmon, NY and Chicago, about 930 miles. Coal was replenished from one of the mainline facilities such as Waynesport rather than having to cut the locomotive off the train at a passenger station.

Many of the old coaling towers were so well built that it is prohibitively expensive to take them down. Since they are structurally sound and do not interfere with the operations, they remain standing.