Half schnabel refers to having only one gooseneck assembly vs the two on a full schnabel. The half schnabel has some significant advantages over the full schnabel. The low tare weight allows for a high payload capacity with relatively few axles. This low tare weight is attributed to having only one gooseneck and the rear dolly uses the tower as a structural member. The dished cross members in the dolly allow the tower section to sit lower than the diameter of the tire.
The loaded length of the trailer is the combination of the tower section and the gooseneck. This short length compared with the full schnabel may reduce some permitting costs and open new routes.
The schnabel neck has integrated hooks that mate with the dolly to pin them together for the return trip. The return hookup process takes about 15 minutes.
The 2+2 dolly has 4 steering axles that receive their steering commands from the gooseneck’s coupler plate. The steering geometry of the dolly is strategically made to handle the long upper and mid-tower sections. The center of steering is ahead of the front tandem group. This effectively makes it track and feel like a much shorter trailer. This shorter feel is also captured when reversing. As a general guideline, the trailer will react as if it is half the length. A 120 ft trailer length will feel as if it is 60 ft long.