Nelson Civil Construction of Nelson, New Zealand, is leveraging the experience of its employees with advanced GNSS-based grade-checking technology. And is boosting its productivity by more than 50% as a result.
Darryl Gibbons is a third-generation construction professional who recently sold his family business only to start up again from scratch. His new company, Nelson Civil Construction (NCC), services the top of New Zealand’s South Island as a principal contractor on residential and industrial subdivisions, and as a subcontractor for roading work. Darryl’s seven employees operate the company’s graders and excavators.
Working relentless 12-hour-plus days, 5 and a half days per week, Darryl and his crew were looking for ways to improve their efficiency on site. They wanted to reduce downtime and increase productivity so they could finish their current jobs faster and take on more.
NCC recently invested in the cost-efficient Trimble Site Positioning System (SPS) Essentials Kit featuring a cable-free Trimble SPS985L GNSS rover. A Trimble SPS855 GNSS base station supports the rover. The Trimble Essentials Kit system enables NCC to measure points, check grade, and navigate to points of interest.
“We’re just saving and saving all the time,” says Darryl. “With the Trimble system, any time we do anything, we’re saving.” NCC has improved their productivity and profitability with the Trimble system every which way:
- Instant site information enables NCC to confirm accuracy and address minor issues immediately, minimizing downtime.
- Less downtime means NCC can achieve more each day and finish jobs faster.
- NCC employees perform their own basic positioning work, so the company relies less on external surveying services for minor tasks, which saves time and money.
- NCC can more readily respond to site conditions. For example, when the weather is fine, work can begin regardless of surveyor availability.
- The Trimble SPS system is so easy to learn that all of NCC’s employees use the system with confidence.
- Employees report feeling less fatigued at the end of the day, and better able to perform on the job as a result.
- The job site is safer for employees as they can check surface heights away from excavator arms.
- Improved accuracy enables NCC’s excavator and grade operators to complete tasks in just one pass without rework; saving time, person hours, and the costs associated with machine use.
- Digital data replaces multiple unwieldy paper plans.
As Much Work as NCC can Take On
The sunny Top of the South of New Zealand is booming. Nelson, with its attractive climate, golden beaches and relaxed lifestyle, appeals to many who wish to migrate to the region. For this reason, the area’s demand for new housing and industrial development is unrelenting. And NCC’s schedule is fully booked for the next two years.
This consistent workload prompted Darryl Gibbons, NCC’s owner and General Manager, to realize that the company needed to increase its efficiency by employing more advanced tools on the job site. But his seasoned employees—who started out in the industry with string lines and boning rods—shared some anxiety around adapting to new site technology. Would they be able to use it, or would it “go in the cupboard under the stairs”?
Darryl deliberated for a year before inviting demonstrations for advanced grade checking systems. But as soon as he saw the Trimble SPS Essentials system in action in a demo by SITECH New Zealand, Darryl hesitated no more. He was impressed by the system’s performance and capabilities, along with recommendations from colleagues in the industry. “General feedback from local surveyors was that it’s a top-of-the-line piece of kit,” says Darryl. But it was the system’s user friendliness that proved the decider—Darryl himself was checking grades with the system within the first half hour of the demo—and he purchased the Trimble SPS Essentials Kit right away.
Every member of the NCC team learnt how to use the system in less than three days—even those who still resist email and texting technology. In particular, the SCS900 field software was very intuitive. For example, cut and fill are displayed simply as easy-to-interpret up/down icons on the screen. But employees also noticed that using the system was physically easier to use than their traditional methods, and it left them feeling less fatigued at the end of each day. Unlike straight edges and tape measures, a GNSS-based system does not require bending for long periods or kneeling, so now employees can keep their minds on the job, not on discomfort and tiredness. The job site is better for health and safety overall, as grade checkers can now measure surface heights away from the excavator’s swing area.
Improved Productivity All Day, Every Day
Darryl and his team work predominantly on rolling to steep hills comprising rock or clay and everything in-between. Their main orientation is the Moutere region, just west of Nelson.
NCC is typically responsible for services such as water reticulation, telephone reticulation, deep to medium drainage, and footpaths (sidewalks) on new subdivisions. They use the Trimble system to provide instant grade information, which enables them to maintain accurate progress reports, confirm construction accuracy against a subdivision’s design, and check grades for their machine operators. If grade isn’t checked on a timely basis, work can be delayed or errors introduced, resulting in costly rework.
NCC have set up a Trimble GNSS base receiver over a known point—from that location the base can support multiple jobs with correction data within a 5 km (3 mi) radius. Each night the GNSS antenna is stored away safely; in the morning installation is as easy as screwing the antenna back into position. When the receiver is turned on, a Trimble function called Autobase recognizes the instrument’s position and data begins broadcasting.
Initially, 3D digital plans from the subdivision designers are prepared in Trimble Business Center - HCE office software then loaded onto to the Trimble Site Mobile device. The file transfer takes place via the Trimble Connected Community, which synchronizes files on the Cloud with those on the Trimble Site Mobile device.
NCC are able to receive real-time support from SITECH NZ via Remote Assistant. Remote Assistant enables another user, such as the support person at a SITECH dealership, to view the SCS900 software from anywhere without going to the site. The support person can take control of the device—even pulling data from it—for online training or troubleshooting.
At the start of each job, the base station is set up and the site is calibrated. Then, each subsequent day setup is fast and easy: They turn on the base station and use the rover to check a control mark. This first step confirms accuracy before any grade-checking data is collected. The control point is stored in the SCS900 software, so if the accuracy of NCC’s work is questioned later, they can prove the quality of their data.
Armed with 3D digital design data on the Trimble Site Mobile device, NCC employees use the system to carry out measurement tasks very quickly. An initial site survey verifies elevations and volume estimates, while regular site measurements allow NCC to check progress without waiting for a surveyor—they record layer information, calculate stockpile volume changes, and can immediately take action to address problems on the subdivision. They also record as-built information, which they can forward to their surveying consultant directly from the field—the Trimble Site Mobile device has a modem with which they connect to the Trimble Connected Community.
NCC used to wait for subdivision curbs and channels to be constructed before they could perform their other services. Now, because design strings are supplied in the digital design, they can set out any time. They no longer need to manually measure offsets from the new construction, which is time consuming. They also avoid the risk of damaging the new curb.
“Realistically, I don’t know how we survived before; we’ve changed the whole way we do things,” says Darryl. “We’ve sped up every job by about 50% or more. For instance, trimming of subgrades for footpaths would normally take 10-12 hours, but now on some jobs we’re knocking them over in 15-20 minutes.” Darryl also said that 300 square meters (984 square feet) of footpath (sidewalk) usually demands 30-40 person hours and 12 hours with a digger. If the work is then discovered to be 50 millimeters (2 inches) too high or too deep, NCC needs to correct the problem. Now, with an advanced grade-checking system, rework isn’t necessary because the results are accurate at the first pass.
Sending Ripples and Making Waves
NCC’s adoption of a modern grade-checking system has caused ripples in the local industry. Their efficiency has increased so much that other contractors have visited NCC on the job to see the Trimble SPS system in action. And Darryl says their observations are consistently along the lines and vernacular of “if you old buggers can b@#$%* handle it, then we can too”.
Darryl isn’t troubled that his peers want to increase their competitiveness by adopting similar systems. “This is a small town,” he says. “We still run on a gentleman’s handshake in lots of ways.” And it does to the extent that Darryl allows other contractors to access the signals from his Trimble GNSS base station at no charge. The idea that he could profit from the data is preposterous to him. “We’re pretty casual around here,” he says with a laugh.
Some reactions have been less than enthusiastic, however, with local surveyors being either receptive or skeptical. Typically, surveying consultants will check contractor work every 20 meters (65 feet) for accuracy, but when NCC started performing their own basic positioning tasks, some consultants cautiously began checking work at every 3-4 meters (10-13 feet). Convinced they would find mistakes and errors, they instead discovered that the Trimble GNSS-based system performed almost equally as well as their own field gear.
The Next Logical Step
Before adopting a GNSS grade-checking system, NCC was spending NZD$12-14,000 per month on surveyors, who were frequently unavailable when needed. The surveyors were also reluctant to travel to the job site for small tasks such as replacing a survey peg. “Now we get instant information with our Trimble SPS Essentials system,” says Darryl.
Darryl is now in total control of his job site, but he doesn’t plan to stop at grade-checking. Instead, he is eyeing up the productivity gains his small company is sure to achieve with an on-machine grade control system. “It’s the way of the future,” says Darryl. “Everyone knows it. And if us old buggers can do it, anyone can.”