Ann: Appendix 3B, page-321

From my reading on Vietnamese shallow river sand barges, the bigger ones  seem to be 8-10 m wide & about 30 M L

a single 1500 on barge would have to be 12mW x 80 M L & I would be surprised if Jim can locate such a beast in Vietnam short of a custom build 

which would take 6 months +, IMO. The smaller units have provisions for binding them together which is not all that different to a single large displacement unit. At this stage, time is of the essence and we are lucky that there is a good variety of late model barges available for "fire sale"

prices in Vietnam due to the Government's curtailment of Mekong river sand dredging.