3.3.5 – Sealed and Containerized Loads Containerized loads generally are used when freight is carried partway by rail or ship. Delivery by truck occurs at the beginning and/or end of the journey. Some containers have their own tiedown devices or locks that attach directly to a special frame. Others have to be loaded onto flatbed trailers. They must be properly secured just like any other cargo. You cannot inspect sealed loads, but you should check that you don't exceed gross weight and axle weight limits.