Tanks or containers,
Not the military type of tank, although Atlas handling Uk has supplied castors for the Tank manufacturing industry, no, the type that contain liquid.
Tanks or containers carrying a liquid bring a different dimension into the calculation of what type of castor you need.
In normal circumstances we would all ways recommend that the total load to move on castors must be divided by three. We do this to make sure that a safety factor is built in. You can never guarantee that all the castors are getting an even load in use. This can be down to slight differences in the production in the trolley, the load not been evenly distributed, the floor being uneven and also some difference in the castor tolerances.
When considering tank or container castors or castors on tanks containg a liquid we have to consider the load is not static. Depending on the type of liquid, the quantity of liquid and the type of floor the castors are going to be used on can add extra strain on the castors if the tank is to be moved. In these cases the load of the castors should be calculated over a minimum of two castors and in some cases just the one castor. These will allow the contents of the tank to move around and as the load is shifted the castor will be able to cope with the extra weight.
If a tank is to be emptied before use, it still may be affected by the liquid moving, for example being bumped into or even the filling, therefore we would all ways recommend considering the load capacity of the castors with all the above in mind.