A sliding window of opportunity

21 January 2019

There is a concept in political science known as the Overton Window, after its creator, Joseph Overton. Overton argued that political policy is set within a window—ranging from 'more free' to 'less free'—of public perception of acceptable ideas. Over time, the limits of this window of acceptability change, and the policies politicians propose change with them.

I think a similar concept can be applied to the lifting industry. Over time, the capacity window deemed appropriate for particular segments of the sector will change. Like the changes in public perception of policy framing Overton's window, these changes are not merely driven by whim or fancy, but by material conditions.

We can see one example of this type of change in the broad class of rough terrains, lattice crawlers, and telecrawlers. Increasingly, telescopic cranes in this class use formed booms. This has meant that rough terrains now offer increasingly high capacities, often well over 100t. At the same time, the capacity of telecrawlers has risen, and they offer improved ease of set-up and use.

Not very long ago, the market for initial work on unmade sites, at capacities over, say, 50t, was dominated by lattice boom crawler cranes, with much of the rest using small RTs. Now, the market for these lattice boom cranes doesn't really start at much below 80t, with telescopic cranes still competitive, depending on the project, at much higher capacity points. While there are now more, and bigger, jobs being performed by RTs, these cranes also now face competition on some jobs from telecrawlers.

At the low capacity end, many jobs in constricted or indoor sites that may have been performed using manual handling or rigging systems, are now performed using minicranes. This class of cranes was largely developed in two countries, Italy and Japan: both long narrow nations, with their cities squeezed between mountains and the sea. Indeed, in Japan, one of the main jobs for the first minicranes was placing grave markers in cramped historic cemeteries. Over time, a combination of improved design and features, user inventiveness, and increased regulatory focus on the safety of 'minor' lifting tasks, has seen these cranes on a much wider range of applications: even, in some cases, replacing or complementing the use of tower cranes on skyscraper projects.

Something similar is happening in the truck crane market. Again, not so very long ago, it was common in even developed markets to see truck cranes with capacities of around 12t. In countries like China— which we cover in-depth in this issue—the market was dominated by truck cranes in this capacity class. Now, around the world, the lowest capacity of truck crane offered is generally bigger than this.

Part of the reason for this is that, with the range of features offered—and often required by law—on truck cranes, improved optimisation of gross vehicle weight and capacity, and better boom technology, the slim difference in price between lower capacity models doesn't justify buying a less capable model.

This change in the economics of buying a smaller truck crane, and the development of new segments and classes of equipment, has seen new products take their place on general construction sites.

Increasingly, truck-mounted cranes, once known universally as 'loaders', suitable only for deliveries, have become competitive for lifting jobs. Aluminium boom truck cranes, once popular only in Germany and surrounding countries, have taken off in places like the UK, where the additional payload made available on the truck by the lighter crane is valued.

And, as Stuart Anderson discusses in this issue, traditional small cranes have been replaced on many construction sites by telehandlers. When I started here, not much more than ten years ago, I attended a crane owners' event where there was much hostility towards the use of this equipment in place of cranes. Now, while it is still clear that telehandlers are not cranes—and cannot be used safely in all the ways a crane can—they are increasingly accepted on the jobs for which they are suitable. One of the most interesting trends Stuart identifies is that some specialist lifting firms are now bringing the same expertise to the use of this equipment, as traditional contract hire firms bring to the use of cranes.

As with cranes, every lift with a telehandler needs to be planned and supervised—perhaps to a 'template' when the job is routine, but still with consideration of the task and site conditions. As the range of jobs telehandlers perform increases, I think there is a new opportunity for hire firms to incorporate this equipment in their fleets, and to bring their expertise in lift planning to its use.