Carriage Optimization Builds Throughput, Recovery And Satisfaction

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With a primary goal to increase throughput, Waipapa Pine took their carriage log breakdown from a fully manual process, to fully optimized. They’ve greatly improved their throughput, and recovery gains are a much-appreciated added bonus.


In 2012 Kiwi Timber Protection Ltd (KTP) of Whangarei, New Zealand purchased the assets of a closed sawmill in Kerikeri, NZ, and reopened the site as Waipapa Pine Ltd. Then they set about bringing the primary process up to current standards.

Today, the Waipapa Pine operation consists of a sawmill, continuous dry kilns, and timber stacking equipment. The mill’s primary product is high grade framing timber for the new house construction market on the North Island, with some export to the Pacific Islands. The facility currently processes Radiata Pine with a single-shift processing capacity of 130,000 tons of logs annually.

Manual Sawline Challenges

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The company’s headrig carriage primary breakdown line was installed by the previous owner of the site. The carriage was a fully-manual operation; the operator was 100% responsible to decide what yield to target out of each log. Three years ago the mill installed a slabber on the line. Although it delivered good production results, mill management identified that manually determining the cuts to make with the slabber added significant time to the process of breaking down a log. With the primary goal to speed up the line, the mill decided to invest in optimization. “We understood that optimization could provide additional benefits, but our main target was to increase production output by reducing the time we spent breaking logs down,” said Grant Arnold, Waipapa Pine Operations Director.

Automating the Decision

The mill decided on carriage optimization using USNR’s Lasar2 front and backside scanners. “Scanning as much of the log as possible is preferred for any mill planning to utilize USNR’s optimized whole log breakdown system,” said Dale Bradicich, USNR International Account Manager. “Depending on the mill layout and available space for front and backside sensors, up to 270 degrees of coverage is achievable on a log loaded onto the carriage.”

Grant said, “We considered other vendors and looked at a couple of other installations here in New Zealand, but when we compared functionality and fitness for our operation there was only one way to go.” He continued, “I have also had experience with USNR optimizers in the past, so I was very happy knowing USNR sets the benchmark with these systems.”

Lasar2 Scanning

Lasar2 is the second-generation laser log scanning technology from USNR. This technology has been used successfully in transverse transport machine centers such as conventional headrig carriages, overhead end-dogging systems and log merchandiser decks, in addition to close-coupled primary breakdown systems such as C-frame carriages and EDLF machines.

The scanner produces “radar-type” measurements of the distance from the sensor to each data point within the field of view, amounting to between 50,000 and 100,000 data points for one side of a log. Using front and backside scanning, a scan image can be created that profiles 75% of a log’s circumference.

Flexible Optimization

The USNR Carriage Optimization system provides detailed breakdown rules that can be set for each species, grade and fiber class, along with other options including configurable face cut orders, configurable minimum opening face sizes and lengths, half taper, full taper, and no taper options.

Multiple adjustable scan zones ensure maximum coverage area and maximum scan density on every size of log. The stop-n-loader scan feature allows pre-positioning of the carriage knees to accept the next log, pre-loaded close to the saw line, for faster throughput.

Installing the System

“We are very satisfied with how the project progressed,” said Grant. “Geoff Strang and the group at Skookum Technology (USNR’s agent in the region), Aaron Taitoko and the Tui Technology team, as well as the complete USNR team

working on our project, did an excellent job. My Waipapa Pine team grabbed the project with both hands and worked closely with all suppliers to make the project a success.”

Monica Thomas, an engineer from USNR’s Salmon Arm, BC location, did the initial log study based on information provided by the mill. The study was instrumental in aiding Waipapa’s decision process. To ensure success, Don Getchell, project manager from USNR’s Eugene, Oregon facility, made the trip to New Zealand for the installation. “Training, commissioning and ongoing support from Don has been to the highest standard,” added Grant.

The mill also sent three representatives from New Zealand to USNR’s facility at Eugene for training. “The support and hospitality shown to us by Chuck Blem and the group we met from USNR was great, not to mention the unexpected bonus of donuts for morning tea,” added Grant. “In all we couldn’t be happier with the level of service we received.”

Exceptional Results

“One of the biggest challengers we faced was the time that it took to work through the many and varied recommendations we got from industry players with regards to the pros and cons of spending capital on this equipment,” said Grant Arnold. “This delayed the achievement of the excellent results we have seen.”

With this optimizer upgrade, all three key production measures in the mill have increased. Run rates have increased by 28%, simply as a result of relieving the operator of breakdown decisions in order to concentrate on loading the log, dogging and driving the carriage. The average time to process a log on the carriage has been reduced by 20 seconds. Sawn recovery has increased by about 3%, and graded recovery has increased by 2.9%.

“These results have aligned very well with our business goals,” continued Grant. “Bottom line, we have seen an increase in volume, a higher grade in this volume, and we have cut fewer logs to achieve these improvements. More production, less cost and a better sales mix has given our performance a great boost.”

“In the end, we’re very, very satisfied with all that USNR has done for us,” concludes Grant. “Given the success of this install, we plan to move towards optimization in other key machine center areas in the future.”

Looking Ahead

Grant said, “ The markets here in New Zealand have been very strong throughout 2016 and indications are that this will remain. Like all other sawmillers here, we are working hard to increase production to meet this demand and at the same time lower our operational costs.”

He continued, “As a business we will continue to invest in developing further processing capacity at our Waipapa site as we move through 2017. We have a number of projects due for completion early to mid-2017 and then will move into others towards the end of the year. We are looking forward to these projects being as successful as the USNR carriage optimization project.”