Stacking high
How high to stack? Many rubber-tyred gantry (RTG) yards stack one over five and there is talk of one over six becoming more commonplace, says Royal Haskoning's Jonathan Tyler.
A "tweak" which is cropping up more frequently in discussions, although not necessarily in terminals, is putting rows of RTG blocks back-toback, thereby eliminating a number of roadways. This increases the area of the yard available for stacking by typically 7%-8%, says Mr Tyler. "However, there are operational trade-offs to this arrangement and usually some engineering infrastructure challenges to be overcome." According to Halcrow's Richard Clarke, the optimum stacking height depends on how constrained you are for space, but in general a large, flat terminal with stacks not too high will always be more efficient than a small one with stacks high.
