Holdfast Training Services Trial Blog

The Problem

In a skyline full of Tower Cranes (TC) and rapidly rising high end residential and commercial projects, I confidently assumed that the ability to move construction resources around each of the capitals many project sites was a well-managed logistical challenge. Unfortunately, one of the seemingly obvious issues currently causing some contention on my site is the limited availability of heavy lifting equipment. You would think that providing enough lift capacity for a large construction task is a simple thing to get right but as it currently stands, the project has only one TC supporting all construction activities. That comprises a lot of lifting operations; particularly when you consider it includes support to permanent works on three different buildings, temporary works, scaffolding movement, routine site support tasks such as waste removal and welfare setup, concrete placement, unloading of frequent deliveries and support to a MOLA (Museum of London Archaeology) investigation ongoing in one isolated corner. It is clear that almost all work activities on site requires lift support in one capacity or other.

 
From a project management and commercial perspective this creates an interesting working environment. As a direct result of the apparent shortfall,  the subcontractors are now competing for the limited available crane support on a daily basis. In many cases these same contractors are subsequently struggling to achieve progress in line with their own ambitious build schedule because, according to every daily progress summary I have attended so far, the TC is unavailable to move equipment and resources across our very constrained site.

Issue Mitigation

 
To attempt to mitigate this issue, the principle contractor have temporarily allocated control of TC1 to the sub-contractor completing the essential works on the critical path. As it presently stands that priority lies with the slip form construction of the central concrete shear core in the main tower, currently up to level 2. This core is being constructed in two sections due to its size. For context, each half of the slip form requires approximately 50 crane lifts per day to feed a 50 man gang with all of the steel, formwork and resources required to maintain the scheduled form rise of 1.4m per day. This estimate only includes lifting the resources from the storage area up to the formwork and does not also include unloading upwards of ten lorry deliveries of resources each day. Movement of scaffolding, concrete decking formwork, and the lifting of structural steel frame elements into position are all in competition with the slip form for crane time.

The project management team are also now considering options to reduce the impact of this crane issue on the works programme. These include the installation of a temporary crane (Limited capacity of only 3 Tonnes) in addition to weekend and night works, both of which will increase the overall cost of the works in the short term.

Cost Implications

In numerous situations many of the contractors have brought in labour and resources to complete tasks, only to find that the crane has been allocated in support of other activities. As a result there are frequent occasions where a contractor has workers and resources on site yet is unable to complete scheduled work, at significant cost to both the main contractor and sub-contractor. The resultant effect is that other structural elements and less critical works are now falling weeks behind the original build schedule. This inevitably causes dispute between various sub -contractors which requires careful management and the occasional element of low level dispute resolution.

 
I suspect this will remain a considerable project management issue until TC2 and TC3, self-climbing cranes suspended from the main shear core, are installed once it reaches floor 10. In the long term it also has potentially significant contractual and commercial implications. Brookfield Multiplex almost exclusively use sub-contractors for all construction aspects on their projects. The only element that they seem to provide themselves is the provision of the Tower Cranes. When the sub-contractors designed their own programme and tendered for the works package they considered availability of lift in accordance with the main contractors lifting plan.

Who is to Blame?

 
As you would expect on a project of this scale (£460m), identifying and apportioning responsibility for the issue is an ongoing priority. On this project there appears to be an underlying discrepancy regarding the understanding of crane availability during the early stages of project procurement. The Project Managers (PM) formal position is that all the sub-contractors were informed that there would only be TC1 on site at this stage of the project. He is therefore of the view that they costed and programmed the work on that information and therefore responsibility for delays and subsequent costs lie solely with each sub-contractor. The sub-contractors by comparison have stated that during the initial tender process they were told there would be a second TC available by this stage, effectively placing responsibility for delays at the door of the main contractor.

 
Though all parties on site are working hard and compromising for the benefit of this project, it will be interesting to see where overall responsibility for delay costs fall should elements of work continue to fall behind schedule. As a result, the sub-contractors complain regularly about the lack of crane time (every meeting), I assume to record the issue from their perspective before it leads to an expensive compensation claim further down the line. Likewise, the project management team appear to be strengthening their own position on this issue to allow easy apportion of responsibility elsewhere in order to protect the interests of their own profit margin.At the moment the lack of adequate crane support is not impacting on the critical path, but with weekly site running costs in the region of 300k, further long term delays arising from this simple problem are likely to have expensive consequences into the future.