Foregoing outdated practices in favor of newer technology nets benefits at UCSD housing project.
Almost one-fifth of the way through the 21st century, it’s hard to imagine technology still being able to supplant manual work of any kind. After all, heavy machinery is on the verge of autonomous operation and is increasingly being controlled by GNSS-based systems; concrete buckets and mixers have largely given way to pump trucks with hundreds of feet of reach; even the simple hammer has been all but eliminated by pneumatic nail guns. Yet on many jobsites throughout the world, layout for a structure’s mechanicals (water, gas, waste, etc.) is still done using a measuring tape, a string and a lumber crayon. Not so for HPS Mechanical which is well into its fourth year embracing layout technology based on a robotic total station. Currently working a student housing project near San Diego, the company has both dramatically streamlined its workflow (replacing an approach that would have taken four to five times longer) and reduced manpower needs (resulting in a savings of almost $200,000) on that multi-phase job alone. It has also led by example, recently convincing an electrical contractor working alongside them — actually, one of the largest ECs on the west coast — to adapt the same solution which has proven so successful for HPS. Great minds think alike.
You See, San Diego
Located in the San Diego community of La Jolla, the University of California San Diego (UCSD) has everything a college student could want: a solid US News and World Report national ranking (41st); affordable in-state tuition; and a truly idyllic location, less than a mile from the Pacific coast. Largely because of those selling points — and others — the university has enjoyed impressive growth over the years, increasing by 33% over the last decade alone. To accommodate that steady increase, they’ve undertaken a series of expansions, the most recent of which is a $211 million graduate student housing complex called the Mesa Nuevo East and West Campus Housing project. Working as a subcontractor to joint venture GC Hensel Phelps/Mithun, Bakersfield-based HPS is providing all the mechanical layout and installation. According to Les DenHerder, HPS’s president, the project is sizeable.
“We’ve already completed two previous phases which included a total of eight structures ranging from five to 12 stories in height,” he said. “The third phase, which we are on now, has a total of six buildings with heights from three to 12 stories. To keep production up, we are shuttling between a couple of buildings simultaneously, doing layout for hot and cold water, waste and gas. In the past, layout of this type was a fairly slow, labor-intensive process, in which a crew, working off a drawing, would determine each point using a tape measure and string. If we were still using that method, it’s questionable whether we would even bid a job as huge as this at all. But if we did, it would have demanded a much larger workforce and probably still have taken longer.”
Making a Point
To put HPS’s layout effort at Mesa Nuevo into perspective, one has to appreciate just how many points need to be laid out to get every sleeve and insert in its exact position. Sleeves, for those not familiar with the process, are devices affixed to the deck which, after concrete is poured leave an opening in the slab — in this case for pipes to pass from one floor to the next. Inserts are smaller devices with threads at the bottom which, once the form is stripped, will allow pipe hangers to be threaded into the slab from below.
According to Shawn Hanson, project superintendent for HPS at the Nuevo site, collectively between all the structures, each floor averaged about 1,175 individual points for those sleeves and inserts.
“For all the buildings that will make up this entire complex, there are 109 floors that need to be laid out in advance of slab pouring,” he said. “Running the numbers, that’s 128,075 points for the entire project. A huge undertaking — if done in the traditional manner.”
Fortunately for HPS, some research they conducted in 2014 and a subsequent call to Topo Element Equipment, the San Juan Capistrano-based Topcon dealer for survey equipment, introduced them to the Topcon LN-100 Layout Navigator.
“Chad Dickey, our sales rep from Topo Element has been outstanding since day one,” he said. “He came out and set the first unit up in our parking lot and really helped us get familiar with it. Anytime we need anything, he is quick to respond, mostly with an onsite visit. The LN-100 is genuinely easy to operate but, when people ask how the learning curve was for us, I like to joke and say that for me the first six months were tough, but for all these young guys it was only a couple days.”