The Hansa-Brandenburg GW was a twin engined torpedo aircraft with two Mercedes-Daimler D IIIa. It had a single rudder.
I have this photograph of the GW/3 Marine Nr. 646 with triple rudder (source: Pawlas, Deutsche Flugzeuge 1914-1918, p. 142). At least the prototype of the GW had triple rudders. I suppose GW/3 indicates the triple rudder?
Marine Nr. of the GW: 528, 620-624, 646-650, 700-704,1080-1084.
The was also the GDW, a bigger version of the GW, with 2 x Benz Bz IV, 200 hp. A single prototype, Marine Nr. 746.
And sorry, but I don't have a picture of the W 37.