these mixers normally haul up to 14.5 cubic meters, but have been known to carry 15 in a pinch...

They should have the drop-frame on the trailer chassis to put the drum on a steeper angle (and lower the center of gravity), then they'd haul more. (in a pinch). That's the first tri-drive tractor I've seen pulling a trailer mixer. I've seen tandem tractors with tridem trailers, but the tridems slid forward to unload, and for job-site maneauverability.

there are a couple trailers around here with the drum dropped in the frame like you say, they have a 11M drum set at a steeper angle told hold more concrete (12.5M I believe)... The problem is that with the drum at such a steep angle they don't mix worth a SH&^... usually the last half meter out the drum is almost straight rock, it's so bad that often the last half meter is sent away with the truck because it is not "pumpable".. I am guessing that because of the steep angle on the drum all of the stone settles towards the bottom. The trailers like the one in the photo seem to mix just as well as any standard 11 truck.

IC

After downloading half barrel again trying to mix the concrete should work fine stirring ..... :)

Wow, that's a loooong trailer. We've got a couple of semis to, but they've got hydraulic movable pin and wheels, both for weight and also for manuvering.
It gets so small you can turn it inside a 2 lane tunnel.

Heeere's the MUD!