BY ROBERT P. MADER
Of CONTRACTOR’s staff
PHILADELPHIA — Most workers aren’t goofing off. In fact, only about 5% of the time spent on a construction site is wasted, yet just 32% of a day is spent actually installing mechanical work, engineer Kerry O’Brien told mechanical contractors here.
On a typical project, mechanical trades spend 42% of their time on materials handling and get-ready activities, O’Brien said in June at the Mechanical Contractors Association of America mid-year educational conference.
Contractors have made money for themselves through shop fabrication methods or with innovative materials handling techniques. O’Brien, an Australian-educated New Zealander who now runs his consulting firm out of Toronto, has analyzed the entirety of a construction project’s workflow with the eye of an industrial engineer.
That 212 hours a day of production can be increased to 52% of labor hours through intensive planning, he said. Project managers and field people must brainstorm specific operations that are representative of much of the materials handling on a project. The typical 42% of time spent on materials handling can be cut to 25%, he said.
“This is a big argument for pre-fabbing,” O’Brien said.
The production rate in the fabrication shop is double that of the field because workers can use jigs and templates, have better working conditions and repetition leads to a shorter learning curve. Ineffective time is typically 18% in a shop compared to 25% in the field.
Materials handling time occupies 10% of the time in a shop. The result is that typically 65% of the workday in a shop is productive time.
“It better be,” O’Brien said, “because that’s the whole reason for a shop.”
The project also can be smoothed out in the field, O’Brien told MCAA members. Select a foreman as soon as possible and have a site layout and materials handling meeting, he suggested. Attendees should include top management, project managers and foremen, estimators and draftsmen, purchasing and the pre-fab shop and anyone else who could help improve productivity.
Then go to the site and meet with the GC. Present the GC with your solutions from the materials handling meeting.
Select two or more items that represent the bulk of the project and figure out ways to expedite them. They must be specific — such as how to install 6-in. pipe in a particular area — and they need to represent a decent chunk of hours.
Create a flow chart of how that material will be installed.
Start with packaging. The vendors are going to put together materials for shipment anyway so you might as well have them package the products for easier installation. Specify the type of container that you’ll need to roll through doorways or fit on a hoist. Specify the number of items you want in a container because the quantities should be determined on a per floor, per zone or per run basis, O’Brien suggested.
The idea is to eliminate the go-fetch part of the job. Tell vendors if items should be packed flat or upright. Ask them to color-code boxes, pallets and bags of accessories to your specifications.
Shipping should be requested for just-in-time delivery and to minimize unloading time. Specify which side the pallets should face for fastest unloading.
John J. Kirlin Co. bought second-hand flatbed trailers, O’Brien said, so pre-fabbed assemblies are loaded on the trailers and then taken off the trailers at the jobsite. They are never taken off the trailer, put on the ground and then lifted or moved somewhere else on the site.
It helps if the foreman has a friendly relationship with suppliers who will deliver materials just in time, packaged for the jobsite and take returns.
Truck unloading should minimize time, storage and moving around the jobsite, he said. Materials should be delivered to the specific installation area, floor or zone or to a fork-accessible container.
If you need a truck-level loading dock, it might pay to build your own, O’Brien said. Plan your hoisting needs, such as whether you will need spreader bars.
The contractor should have a materials handling crew. On a small job it will probably be the same two guys who back each other up. It should not be an apprentice, he warned, because he will bug the foreman with too many questions.
The foreman should see at the start of the workday that work areas are clean and materials and tools are in the workspace. If necessary, the foreman and the materials handling guy can work an extra half hour in the morning or evening to make sure the site is organized.
The equipment and materials should be delivered right to the work site, with everything in wheeled containers or on pallets. A toolbox on wheels with a copy of the drawings on top helps speed things along.
Finally, mull over different installation techniques. It might be a good idea to use a small forklift for some installation tasks. O’Brien said he has seen foremen rig up pipe saddles for forks to lift pipe.