If I was to tackle this job and had a few to do I would make a set of 4 hydraulic rams up which hook into the twist lock corners top and bottom
So a box section that is the same length as the container is high with two hooks that locate in both the top and bottom corner twist locks with another box section that fits inside snuggly which has a ram fitted and with a nice big base plate welded the the base it will only be 6 tonnes of ground pressure not a big job could be made for a few grand even less if you know where to look
So a box section that is the same length as the container is high with two hooks that locate in both the top and bottom corner twist locks with another box section that fits inside snuggly which has a ram fitted and with a nice big base plate welded the the base it will only be 6 tonnes of ground pressure not a big job could be made for a few grand even less if you know where to look