InfraStructures - September 2007 - Elevating Cab Gives a Fresh Perspective on Clearing Log Jams

Elevating Cab Gives a Fresh Perspective on Clearing Log Jams

Constantino Lannes, Sennebogen LLC
Special collaboration

For years, clearing cross-ups in the infeed deck has been a simple, and recurring, fact of life at the Swanson Group Lumber Mill, in Glendale, Oregon. To Mike Lawless, the log yard coordinator here, it seemed that continual repaving of the asphalt operating surface that surrounds the mill was another of those jobs that, no matter how well you do it, you will soon be doing it over again.

These jobs may never go away completely, but both of those problems have improved significantly for Mr. Lawless since last October, when he brought the mill's first Sennebogen log loader into service.

The log sorting and cross up management problem was a side effect of an upgrade in 1997 to the dimensional lumber mill. High-speed scanning and production equipment were installed at that time. It was a state-of-the-art system, but the mill soon found that it would have to assign one of its log loaders to pick out occasional jammed/crossed up logs and clear the path as blocks were forwarded up from the debarker toward the mill's infeed.

Mike Lawless' equipment fleet did include a few log loaders, which are normally put to work decking blocks when the log processing output exceeds the mill's production rate. A photo eye senses when the infeed deck is full. The debarked, cut-to-length blocks are then diverted to a surge area so the debarking, scanning and log processing can continue unhindered. The loaders are also used to high deck and feed the mill a select diet of various sized logs to increase the mill's production rate. The grapple-equipped loader selects and feeds the proper mix of logs, ranging from 6-20 inches in diameter, to ensure that the ratio of cants exiting the vertical band saws will keep both the twin and the ganged resaws operating at full capacity, without getting backlogged.

At first, the mill's big wheel loader was delegated to correct cross-ups along with its usual duties. However, the short debarked segments are slippery and tricky to manage for the big machine designed to grab a full truck load of 40 foot logs.

The task was then given to the smaller tracked loader. Unfortunately, this solution came with its own perils. As described by Mike Lawless, the nature of the processing equipment does not lend itself to precision log picking! Seated in his cab, the loader operator had no clear line-of-sight into the conveying area where jams occur. Clearing jams became a painstaking job for two, with a "spotter" acting as a second pair of eyes for the loader operator, helping him guide the grapple to take hold of the jammed log and move it into place.

According to Mr. Lawless, the system was less than perfect - and small misses with the loader proved very costly. Occasionally, through no fault of his own, the loader operator would inadvertently damage a conveyor belt or another piece of equipment with the grapple. The mill's production process, running at 50 MBF per hour, would come to a sudden and complete stop. The repair bill for the conveyor, alone, would cost Swanson thousands of dollars while the lost production cost considerably more.

Times like that gave Mike Lawless more than enough opportunity to observe the other problem his track machine was causing. Pointing to a 30 cm deep puddle in the pavement, he says "...their steel lugs, constantly turning on the asphalt, just ground it away. Every couple of years it was costing us $15 000 to $20 000 to repair the damage to the asphalt surface. Add that to downtime and cost of replacing conveyor belts, this problem with the log cross ups was adding a lot of cost to the operation."

Mike Lawless first became aware of Sennebogen material handling machines as a possible solution when a magazine advertisement caught his attention. Popular in recycling yards and port facilities, Sennebogen green line machines are well known for their hydraulically elevating cabs. Further, in addition to their tracked undercarriages, Sennebogen machines are offered with a rubber-tired platform ideal for operating on paved surfaces.

Mike Lawless sharpened his pencil to calculate the potential cost savings. When the numbers were in, it was clear that the Sennebogen 825 M machine could save them money. Along with its low maintenance costs, the 825 M is much lighter than Swanson's tracked machines and consumes considerably less fuel to operate. He contacted Sennebogen and arranged for delivery of a demo unit to give him a first-hand look at that elevating cab.

Problems solved!
After six months on the job, the Sennebogen 825 M has proven to Mr. Lawless that it is the right machine for his particular application. Although smaller than the mill's other loaders, the 825 M is fast, agile and able to easily complete all of its required tasks with time to spare. And without damaging the asphalt surface!

But it is the machine's ability to elevate the operator above the log jams that gives it a unique advantage over the other machines. "Elevating 5,8 m above ground level makes it easy for him to see the grapple at the end of the boom," Mike Lawless explains. "He can precisely locate the log he needs to free or move. And he no longer needs a spotter to assist him. There's hours of employee time saved and the potential for equipment damage is greatly reduced."

Vernon Richardson agrees. As a loader operator who often takes on the clearing tasks, he asserts that his job is a lot less stressful with the Sennebogen machine. "It's more relaxing now that I'm able to actually see the block I am grabbing. Not having to depend on someone else to be positioned to be my eyes also speeds up my response time in getting the jams cleared."

Fuel efficiency has turned out to be another significant bonus. Consuming less than half the fuel of the larger tracked loaders throughout its two shifts per day, the 825 M will net Swanson better than $50 000 in fuel cost savings for every year in service. Mr. Lawless expects to see even more savings in time, when the machine bears out Sennebogen's excellent reputation for reliability and the ease of maintenance. All routine service points on Sennebogen machines are readily accessible from ground level. The manufacturer also prides itself in its "computer-free" design philosophy. By minimizing their reliance on electronic controls for efficient operation, Sennebogen has achieved dramatic reductions in downtime caused by electronic failures or complex service procedures.

Mike Lawless says he can also foresee Sennebogen machines, and their elevating cabs, taking a larger role in the yard. The efficiency and nimble performance of the green machines could also lead to cost savings in high-decking applications. While the 825 M is among the smaller units in the Sennebogen line, he estimates that an appropriately sized model with the elevating cab could cut the time required for high decking by half - a huge productivity improvement for savings for mills like Swanson that handle and stockpile large volumes of logs.

With the rubber tired Sennebogen 825 M log loader, Mike Lawless found a solution to his log jamming problem and his asphalt maintenance problem - a solution that saves significant operating costs, reduce capital expenses and takes a critical step to prevent unscheduled downtime throughout the mill. The bottom line for Swanson is that their Sennebogen 825 M and its elevating cab are allowing them to run with fewer interruptions.

Sennebogen has been a leading name in the global material handling industry for more than 50 years. Based in Charlotte, North Carolina, Sennebogen America offers a complete range of purpose-built machines to suit virtually any heavy lift or "pick & carry" application. A growing network of distributors supports Sennebogen sales and service across the Americas, ensuring the highest standard of professional machine support and parts availability.