I found this picture while surfing online. If I saw the items by themselves, I would have assumed they were fuel storage units. But the vehicles has its gun attached to them. So what is their purpose?
My best guess is a silencer but that seems very unlikely.
Googling “artillery silencer” gives me this.
With the same picture.
The text of the article strongly implies the primary purpose is not military, concealing the source of the shot from the enemy, but to dissipate the sound for the benefit of civilian neighbors during training at home.
ETA: ninja’ed while making the formatting pretty. Oh well.
Those are exactly silencers. The German army uses them so the noise of their practice firing does not disturb the peace of their civilian neighbors. Unlike the USA they don’t have the luxury of large ranges many 10s of miles from dense population centers.
See here for more pix: artillery silencer - Google Search
The AR National Guard needs some. We are close to Camp Robinson, and the neighborhood go nuts when they have an exercise.
They really couldn’t be military in purpose, because it defeats the whole point of having a mobile artillery platform if you need a huge immobile silencer with it.
Only an organization top heavy with Y chromosomes could come up with a design like that.
I totally see your point, but the reality is rather more mundane. Artillery barrels end in muzzle brakes which exhaust out the sides. And of course the barrels exhaust out the front too. So the three-lobed gizmo matches the three-lobed shape of the exhaust gasses it’s trapping.
I don’t know what irreverent nicknames the troops have for those things, but I bet you’re barking up the right tree. 
I made a joke about it being a silencer because I didn’t think of the possibility of it being used for training.
Ignorance fought (with a whisper of artillery fire). Thanks everyone.
Interesting. In my years in artillery, 13 years, I never heard of, let alone seen, a silencer for a 155. Or for any caliber for that matter. That was my initial guess, silencer.
I’ve had a picture of this as my Zoom avatar since I moved there for COVID.
