Stations often had these Water Cranes at the end of the platforms so the locomotives could be refilled without detaching them from the train. These cranes were usually supplied by a large water tank (see Ratio 506 and 551 and Wills SS34 kits).
Ratio 413 Water Crane and Fire Devil HO/OO Gauge Model Kit
Ratio 212 Water Crane & Fire Devil - N Gauge Model Kit
Ratio 413 OO Gauge Water Crane & Fire Devil Plastic Kit
New Ratio Water Crane & Fire Devil 413
Ratio/Bachmann water tower, signals with Dapol huts, water crane and gauge 4mm
212 Ratio Water Crane & Fire Devil N Gauge Plastic Kit