Jarrad Warhurst is the head of the UK Civil Engineering Department at the Robert Bird Group consulting firm
Why does the crane strategy stop long after the design decisions have been made? Modeling the efficient use of cranes earlier in the process could speed up the construction program, reduce the need for temporary work and improve the overall value of the project.
Civil engineers usually look at value in terms of structural efficiency, but I’d argue that this is a little short-sighted.
At the same time, the increasing focus on techniques such as offsite construction, digital tools and artificial intelligence, which are important to the advancement of the construction industry, is diverting attention away from practical low-tech, low-cost solutions that can now add real value.
In my experience, civil engineers evaluate their projects by minimizing pounds of steel or by maximizing the span-to-depth ratio. This is because engineers’ perception of value is sometimes based on the ethos that the lightest or most efficient design structure is automatically the most cost effective. However, this is a very narrow perception that can actually undermine the real value of a project as this highly efficient structure has yet to be built in the real world.
Crane to add value
An important step in improving project value is to study how the design you choose can have a positive or negative impact on the delivery phase of a project. Looking at Cranage is the first step.
Crane systems are usually brought in by the contractor in the bidding phase, but optimizing the crane system structures at this point is often too late. Productivity inefficiencies are largely resolved at this stage – when the fundamental design decisions have been made.
However, crane decisions can have a profound effect on the efficiency of a project, so they should be initiated in the early design phases.
By including crane systems in the design, a project can be optimized in terms of productivity, an approach that eliminates shortfalls such as B. can reduce temporary work. It can also accelerate the program, limit the number of pieces and increase the sustainability of a project through improved logistics and reduced phase times.
As an example, I have come across a number of long-span structures where only the final state has been considered, ignoring the fact that the worst loads on the structure are actually placed on the structure during construction. In other words, emphasis was placed on keeping the structural elements of the permanent works as small as possible, rather than avoiding unnecessary temporary support work. The optimal crane strategy, based on lifting capacities, would have saved both time and money.
“Engineers need support when placing orders, customers who respect the holistic value, and a collaborative work environment in order to be productive.”
Since wide-span structures can usually account for 40 to 50 percent of the costs, the scope of the temporary work and the logistical constraints of transport, installation space and crane capacity should be taken into account at an early stage, which is often when choosing the structural concept as well as the detailed design.
But of course that is easier said than done. Engineers need support with the award of contracts, customers who respect a holistic value, and a collaborative work environment in order to be productive. Engineers shouldn’t just be measured by delivering the “minimum steel weight” or the “smallest concrete volume”.
The mantra for all projects should be “Design for Delivery”, which is essentially geared towards productivity. It is the process of designing for the building process to ensure that the balance between low material costs and productivity is achieved in order to optimize the value of a project. And it all starts with a crane.