The use of a single tipping ram to tip a trailer body is currently the most popular method used throughout Europe.
Here in the UK cheaper twin ram systems are still fitted by most manufacturers, so what are the advantages of using a single ram?

The ram is mounted in the strongest part of the chassis; in-between the axles.
That means the trailer’s axles carry the weight, not the tractor (which would be the case if the ram was mounted forward of the axles).
As the Harvester trailer only tips to 53° the ram is located in front of the axle.
The single ram directly lifts the body upwards (as opposed to pushing the load backwards against the hinges). This makes the trailer safer as the force that the ram exerts to lift the body (and the force exerted against the hinges) is reduced.

The position and angle of the ram also means only 100 psi oil pressure per ton of lift is required.
1,600 psi will therefore lift 16 tons, while twin-ram trailers would require 2,450 psi to lift the same weight and slightly overloading would mean the tractor’s maximum 3,000 psi would not lift the body.
Ram seals rarely need to be changed as the pressure required by the Larrington trailer/ram design is much lower, reducing wear.
Single ram trailers are more stable. A tractor only has a single pump, in twin-ram trailers the oil pressure is shared between two rams. The ram with the smaller load will extend further, twisting and destabilising the trailer. A single ram lifts the body without twisting it.
Because of the unique design, Larrington Trailers tip quicker than any other tipping trailer we’ve seen.
Please note: Although the single ram’s position looks further back, its position under the body is often only 12" further back than conventional twin ram systems.