and navigated with equal facility as two distinct vessels, as if
combined into one. By the combination of the two semi-barges into one
duplex barge the draught of the vessel is nearly doubled, the ratio
existing between the draught of a loaded semi-vessel and the equally
loaded duplex vessels being 5:8 (up to 8.5)

The advantage of the invention consists:

1. In this difference of draught.

2. In the smaller width of the semi-vessel as compared with
the duplex vessel.

3. In the fact that the combination and separation of the
vessels can be effected, without the least disturbance of the
cargo, in a minimum of time.

It facilitates the utilization, to the highest possible extent, of the
varying conditions and dimensions of canal locks and rivers.

The transition from rivers to canals, and from larger canals to
smaller ones, is expedited by the possibility afforded of, on the
arrival at the locks, dividing the vessel in a space of a few minutes;
of passing with the semi-vessel, singly, the various smaller locks or
the shallow canal, after which the two sections may be re-combined and
navigated again as one vessel. The process of "folding up" the two
vessels will of course take longer than that of separation.

On rivers, the channels of which are interrupted by sand banks and
rapids, the same operation may be carried out, thus avoiding the