Is anyone out there willing to comment on what is going on in the attached photo? My first impression was that this gun is way too heavy for it to be lifted this way. Anyway, I would appreciate it if the vehicles could be identified also.
It is indeed being transported - there are a few photos in Herbert Jaeger's 'German Artillery of World War One' showing various guns being transported in this manner (including a 21cm moerser, though the vehicle involved is a different one).
I don't know the model of truck involved (doubtless others will; there's a photo in Jaeger showing, I believe, the same model truck but hauling a Rheinmetall 15cm K16), but that set-up was called the 'Lastenverteilergeraet', or 'load distributor'. It was the invention of a chap named Brauer, and was put into production after his suggestion to the APK in March 1915. Rheinmetall produced it.
In any case, there's still the question of what truck it is. And I forgot to say what a magnificent photo it is, thanks for posting it - where is it from?
EDIT: A bit more info from Jaeger, on what I suspect is the vehicle in the photo:
On 24 November 1916, KM [War Ministry] laid down the official designations of allmilitary motor vehicles:
Artillerie-Kraftschlepper: tractor, 80hp, with load-distributor for 15cm K16 (Rheinmetall), 21cm mortars and similar
Is this anything to do with the 'Buessing KZW 1800 heavy artillery tractor 1916' listed as a kit on Matador's site (but, very annoyingly, unaccompanied by a photo!):
Christ on a bike, I'm a moron, of course I've seen your model (and dashed good it is too!), but, as per, I hadn't put 2 and 2 together and come up with the necessary...