FLSmidth Salt Lake City, Inc.

Large feed opening

FLSmidth’s Raptor XL500 cone crusher features a large feed opening, high pivot-point crushing action, and wide crushing stroke. Its large 59.06-inch-diameter head and eccentric motion is said to allow feed up to 25 percent larger than crushers with less throw and similar head diameter. The crusher’s 148-inch diameter and 106,500-pound weight offer flexibility for multi-site crushing operations.

Telsmith, Inc., an Astec company

Advanced jaw crusher technology

Telsmith says its H3244 Hydra-Jaw, the largest model in its Hydra-Jaw Series, features advanced jaw crusher technology that offers lower operating costs, increased uptime and production capacity, streamlined operation and maintenance, and greater safety. The crusher’s 32-inch gape and 44-inch width is designed to accept larger feed; the Hydra-Jaw toggle provides hydraulic tramp iron relief with automatic reset, chamber clearing, and push-button setting adjustments. The unit can be mounted on portable plants or modular fixed-structure assemblies.

Terex Minerals Processing Systems

Easy clearing of jammed feed

The Terex Cedarapids MVP450X 400-horsepower cone crusher boasts major new enhancements, including high-speed clearing of jammed material, quick crusher separation capability for fast manganese changes, and easy-to-operate computer controls. The optional “Guardian” PLC control system optimizes production and is fully automated, according to the company. At the press of a button, fully guided dual-action tramp relief cylinders provide 6-inch lift for easy clearing of jammed feed material. The company says the hydro-pneumatic tramp iron relief system instantly resets the crusher setting after passing uncrushable material without having to activate valves and pumps. The hydraulic-powered threaded upper assembly allows for quick crusher setting adjustment under load.

How we made our choices

When we ask readers how we can best help them keep track of changes in the products and services they use to produce aggregates, almost everyone wants an annual short list of the really important stuff.

No wonder. The sheer volume of introductions is overwhelming. Aggregates Manager covers dozens of products each year in its RollOuts departments and Supply Lines features.

So each year, our staff reviews all the product introductions we’ve covered for the past year (our Top RollOuts “year” actually runs from the December 2010 issue through the November 2011 issue) to pick out 25 that we believe are worth further review. Our priorities are new concept products — which are rare — new series/new generation products in categories that relate to the aggregates industry, and other rollouts which serve our readers’ interests by increasing competition in a product category.

Inevitably, we omit deserving products, either because we just didn’t understand the significance of the product or because the announcing company didn’t communicate what was special about the product, or both. In either case, we apologize in advance for these omissions.

This year, we’ve added smart tags that lead to videos for many of the Top RollOuts. These videos include insights from the manufacturers and an explanation of some of the unique features. Go to http://www.gettag.mobi and download the free app, then scan each tag for more information.

KPI-JCI, a division of Astec Mobile Screens

Revolutionary multi-frequency screen

KPI-JCI expects its multi-frequency screen to revolutionize the screening industry. With the combination of both conventional and high-frequency screens, the unit is able to maintain the higher production rates of a PEP screen at a lower angle, while handling higher moisture content materials. Coarser material requires more amplitude and less frequency, while finer material requires less amplitude and more frequency. The multi-frequency screen combines both theories. By working at a lower operating angle, the overall height of the screen is less — making it safer to work on and operate.

Sandvik

Sets new throughput standards

Sandvik says its QE440 scalping screen sets new throughput standards for the industry with over 40-percent greater screening area than the former market leader, the QE340. The 76,360-pound machine features stockpiling conveyors that are wider and higher for increased production capacity and larger stockpiling capabilities. The 53-foot, 6-inch unit is easily transported due to its hydraulic folding tail and side conveyors and its fully tracked chassis. Additional features include a screening surface 40 percent larger than its predecessor; and stockpiling conveyors in three sizes — oversize (5 feet, 3 inches wide and up to a 13-foot, 7-inch discharge height), mid-size (3 feet wide and a 13-foot, 11-inch discharge height), and fines collector (3 feet, 3 inches wide and a 13-foot, 8-inch discharge height).

Metso Minerals

Increased production

While banana screens are said to offer 40 percent more production on the same footprint as a typical incline screen, Metso says its Ellipti-Flo screening system is expected to increase production by an additional 30 percent over the banana screen. Designed to handle separation of traditionally challenging material such as wet, sticky feed, the system also has high-load, bearingless exciters.

Atlas Copco

Increased feed capacity

Atlas Copco says its line of track-mounted Powercrusher mobile crushers and screeners includes four jaw crushers that incorporate “Quattro Movement” for maximum processing efficiency. Quattro Movement is made possible by an up-thrust toggle plate position. This causes a figure-eight motion in the moving jaw, which increases the feed capacity and produces a post-crushing effect as rocks exit the crushing chamber. Models include the PC 1055 J with a total weight of 34 metric tons and an output capacity of up to 200 metric tons per hour. The 40-ton PC 2 delivers up to 250 tons per hour. The PC 4 weighs in at 45 tons and provides up to 300 tons per hour. The 55-ton PC 6 has a double-deck independent pre-screen section just before the crushing chamber and delivers up to 350 tons per hour.

Metso Minerals

Produces two-sized fractions

Metso says its Lokotrack ST3.5 portable plant can produce two-sized fractions, with an optional two-deck vibrating grid that can be installed to yield three-sized fractions. The unit’s screen box is 11 feet, 7 inches by 5 feet with a 57-square-foot screen area and is powered by a 100-horsepower Cat 4.4 engine. Four identical meshes are used on the screen to lower stock requirements.

Kleemann/Wirtgen America Inc.

Mobile impact crushing

The MR 110 Z EVO impact crusher from Kleemann features a new material flow concept — the discharge belt is 4 inches wider than the discharge chute which is 4 inches wider than the inner width of the crusher. The rapid flow of material keeps it away from the critical area under the crusher and reduces wear. Additional features include an independent vibrating double-decker pre-screen and a newly designed crusher bypass that includes changes to its geometry and form to boost performance and reduce wear. Optional new and improved screening units are available and are more than 44 percent larger in size than those on previous units, allowing for tonnages of between 350 and 450 tons per hour.

Screening and Crushing Solutions

World’s largest mobile cone crusher

Screening and Crushing Solutions says its TC1885 is “the world’s largest-ever mobile cone crusher.” The machine is powered by a 27-liter, 875-horsepower, twin-turbo, V12 Caterpillar engine. The crushing unit weighs 71.7 tons on its own. The closed-side setting can vary from 65 millimeters down to 15 millimeters. Four concave options are available with feed openings of 19.7, 14.2, 9.4, and 7.1 inches. The crusher, originally manufactured for a mining and demolition company in Australia, will be available globally.

Mettler Toledo

Eliminates repair costs, downtime

Mettler Toledo’s VTS101 truck scales use a Powercell PDX load cell technology that eliminates the typical maintenance, repair costs, and downtime related to conventional vehicle scales. The VTS101 consists of a steel deck supported by orthotropic ribs that are sealed from the elements by automated continuous welds. The company says the Powercell PDX load cell provides predictive diagnostics, including automatic notification of weighing errors, overloading, environmental conditions, network health, load-cell voltages, and enclosure integrity, without the need for maintenance-prone external converter boxes.

Telsmith, Inc., an Astec company

Automatically adjusts feed rate

Telsmith’s Tel-Trax Model TC52 high-capacity, track-mounted cone crushing plant is built around the 400-horsepower model 52SBS cone crusher. The plant boosts tonnage output in secondary and tertiary applications, while accepting larger feed (up to 12-inch topsize) than 300-horsepower units. The unit is outfitted with automation controls that automatically adjust the feed rate and reduce the need for operator oversight by monitoring parameters such as crusher overload, feed-bin levels, diesel power supply, and the discharge conveyor. The automated controls package also allows a soft link to additional Tel-Trax crushing and screening plants to provide a completely linked and integrated processing solution.

Caterpillar, Inc.

Load-sensing hydraulics, increased power

Major improvements to Caterpillar’s 980K wheel loader include a new cab, load-sensing hydraulics, a 25-percent increase in lift force, and a 16-percent increase in tilt force over its predecessor, the 980H. The machine also features new electro-hydraulic steering with joystick or steering wheel control, Performance Series Buckets, and an optional lock-up torque converter. The machine is equipped with the new Tier 4-Interim Cat C13 ACERT engine with peak net power of 369 horsepower at 1,500 revolutions per minute. The loader accommodates buckets ranging in size from 5.25 to 16 cubic yards.

Doosan Infracore Construction Equipment America

Z-bar lift system

Doosan’s 301-horsepower DL450 wheel loader boasts a robust Z-bar lifting system that provides a breakout force of 53,572 pounds. Additional features include a quiet, comfortable cab and easily accessible maintenance points. The machine is available with buckets ranging in size from 4.5 to 6.3 cubic yards.

Volvo Construction Equipment

Fills on-highway trucks in two passes

Volvo says its L250G wheel loader is the first wheel loader specifically designed to fill triaxle, on-highway trucks in only two passes, which means up to 30 percent more trucks can be loaded per day. The machine is powered by a Tier 4-Interim-certified engine with OptiShift transmission for enhanced fuel savings. Additional features include an adjustable declutch, electro-hydraulic controls, oil and fuel filters in one location for easy maintenance and less downtime, and a reverse camera. CareTrack is provided as standard equipment, free for three years.

Case Construction Equipment

Reduced fuel consumption, improved performance

Case’s 207-net-horsepower CX300C excavator features Tier 4-Interim-certified cooled exhaust gas recirculation technology. Its new Intelligent Hydraulic System technology is said to reduce total fuel consumption and improve performance. Swing Relief Control technology manages the hydraulic power allotted at the start of the swing operation, and Spool Stroke Control creates an automatic pressure adjustment during digging operations. The machine offers up to 6 percent more lift capacity than its predecessor and has an operating weight of 65,900 pounds. A rearview camera feeds video to a 7-inch LED monitor to expand the operator’s view around the machine. An in-cab auxiliary hydraulic setting system features a new option for 10 memory-recall settings to make tool changes quick and easy for operators.

Liebherr

Sets new standards for productivity

Liebherr claims its R 9100 mining excavator sets new standards for productivity, reliability, and cost efficiency in the 100-ton class. The excavator’s V12 engine has an output of 565 kW (757 horsepower). The specially shaped 6.8-cubic-meter bucket increases penetrating power and fill factor. A wide catwalk makes access to the various mechanical assemblies easy. Other features include an operating weight of 110,100 to 114,000 kilograms, a machine monitoring and control system, and a new cab design.

Caterpillar, Inc.

Six-wheel drive with torque distribution

Cat’s 740B articulated truck offers a Tier 4-Interim-certified emissions configuration and 43.5-ton payload capacity. The improved cab features a redesigned instrument cluster and customizable, multi-purpose display; a new headliner with switches for electric mirrors and regeneration operations; an upgraded driver’s seat with multiple position adjustments; and an engine hood raise switch. Cat has improved its six-wheel-drive system with a torque-distribution, automatic traction control (ATC) system, which is said to eliminate the need for driver intervention to maintain traction in difficult operating conditions.

Bridgestone Americas Off Road Tire, a division of Bridgestone Americas Tire Operations, LLC

More even footprint pressure

The 45/65-45 DuraLoad off-road loader tire from Bridgestone stands out with features such as a flatter crown radius for more even footprint pressure and less heat generation. The tire’s design includes shoulder tie bars and is said to allow easier mounting. The tire will be available in L4, L5, and L5S designs to fit the needs of most loader operations, with or without chains.

Komatsu America

Automatic traction-control system

Komatsu says its HM300-3 articulated truck features a Tier 4-Interim, 325-horsepower engine; a gross vehicle weight of 115,147 pounds; and a payload capacity of 31 tons. The truck’s Komatsu Traction Control System (KTCS) automatically engages to maintain performance in soft ground conditions. A new cab design provides good visibility and easy access to machine controls. Complimentary factory-scheduled maintenance for 2,000 hours or three years comes standard with every lease or purchase.

Michelin Earthmover

Longer tread life

Michelin’s XDR2 tire for rigid dump trucks is said to offer up to 20 percent more tread life than its predecessor, the XDR. In addition to increased tread life, the tire features up to a 10-percent thicker undertread between the protective plies and tread base for better cut and impact resistance. Other features include a self-cleaning tread pattern, full-depth blocks, a 13-percent-larger central lug (compared to the XDR), a non-directional design to provide increased protection against aggressions and cut separations, an evolving tread design that provides an increased contact patch as the tire wears, sculptured cooling vents to help keep running temperatures low, and Michelin’s C2 Technology in the casing to provide an overall cooler operating temperature.

Titan Tire Corp.

Improved heat dissipation

Titan Tire says its next generation 007 MFT mining tire offers enhanced durability, a more aggressive tread pattern, and improved heat dissipation. According to the company, testing shows that the nylon casing design ran 15-percent cooler than the steel casing in an equivalent tire. A new triple-bead belt package is said to improve durability, as well as the cut, chip, and wear characteristics of the tire. Sipes are incorporated into the tire lugs to provide additional traction and heat dissipation, which makes the tire less susceptible to sidewall fatigue and cut damage. A non-solid, center-tread design helps reduce internal heat generation and allows the heat to more easily dissipate. The tires are available in 59/80R63, 53/80R63, 40.00R57, and 27.00R49 sizes.

Jingjin Filter Press Co./Tons Per Hour, Inc.

Replaces belt presses, eliminates settling ponds

Jingjin Filter Press says its large filter press can replace belt presses in nearly every application, eliminate settling ponds, and recycle more water than alternative methods. According to the company, the filter press requires no operator and offers a higher quality of filtrate than a belt press, dramatically dryer solids, and reduced handling cost. The unit boasts capacities of up to 23 cubic yards of solids per cycle and up to 4.5 cycles per hour. Return on investment when replacing a belt press is said to be one year. The filter press is available in North America through Tons Per Hour, Inc.

W.S. Tyler

Transforms fines into saleable material

W.S. Tyler says its Haver pelletizing disc transforms wasteful fines into a transportable, saleable product. The disc offers variable side-wall height, speed, and inclination. Its direct-drive technology works without a gear box and hydraulic coupling, eliminating the maintenance required for traditional components. The efficiency of the drive is said to minimize energy losses, reducing total energy costs up to 5 percent.

Superior Industries

Extra-large-capacity truck unloader

Superior Industries says its extra-large-capacity RazerTail truck unloaders are available with a 72-inch-wide by 75-foot, 6-inch-long belt. The unit is engineered to handle material up to 8-inch minus and features a deeper hopper and 8-foot, 6-inch grate with a large 9-foot by 9-foot grate opening. The unit requires only 44-inch earthen ramps and features a hydraulically raised conveyor and optional self-cleaning ramps. The series also includes a low-profile model with a 72-inch belt and 22-inch earth ramp requirement, and a 48-inch belt model with a 32-inch earth ramp requirement (also available in an adjustable height discharge model).

by Austin Amos

It is important to note that a conveyor belt scale is no different than any other type of scale (i.e., lab balance or truck scale) in regards to the need for recalibration. Because a belt scale provides a “weight-in-motion” (unlike the static weight of a lab balance or truck scale), if the speed, zero, or span reference numbers of your belt scale have drifted, you will face a compound effect of inaccuracy over a given period of time (hours, days, or months) with a running conveyor belt. This will amplify the difference, positive or negative, between the weight shown on your belt scale integrator and the actual weight of the material you conveyed.

Recalibration of the belt scale once per month is recommended; however, some applications, at a minimum, can be lengthened to once every three months, with each particular application being somewhat different. The calibration of the belt scale can drift slightly (either positive or negative) due to wear on the belt scale, changing conditions of the conveyor belt, or deviation through the continued operation of the conveyor. Monthly calibration of the scale is preferred to keep these changing factors in check with the conveyor belt scale.

It is also important to note that the calibration procedure presented in the reference manual provided by the conveyor belt scale manufacturer should be followed in order from start to finish. Most discrepancy issues regarding accuracy are related to not following the required steps of the calibration process correctly or totally ignoring some steps completely.

Calibration procedure

Typically, the conveyor belt scale integrator will have a Setup/Calibrate mode that must be selected by the user in order to change the instrument parameters or run calibration tests. When in this mode, integration stops. The calibration process involves the completion of speed, zero, and span tests.

Some integrators feature a menu-driven display that has multiple lines of full English text for display/entry of the setup parameters for the scale; some require the user to refer to their operator’s manual for a code decipher listing of each code that is given on a strictly numeric display.

Speed test

The addition of a speed sensor to the conveyor belt scale allows the integrator to process and display a “weight-in-motion.” The exact measurement of the conveyor belt speed is critical to conveyor belt scale accuracy. The speed sensor provides a constant measurement of the rate (unit of length/unit of time) of the conveyor. Any change in speed from a loaded or unloaded belt based on material flow is directly transmitted to the belt scale integrator along with the signals from the load cells. The integrator handles the processing of the “integrated” speed and weight and provides the user a “weight-in-motion.”

The user would complete a speed test by first calculating or measuring actual belt speed using a handheld tachometer. For the speed test, the conveyor is run empty (without material) up to normal speed.

Zero test

The belt scale integrator receives pressure signals by voltages generated by load cells and mathematically converts them to the rate, commonly in short tons per hour. It also provides the total mass of the material which has passed over the scale for a certain period of time, also commonly in total short tons.

During the zero test, the conveyor should be run to speed without material being loaded onto the belt to achieve the zero of the belt scale. Specifically for the zero test, there are no calibration test weights used. Calibration test weights are further defined below.

Span Test

The purpose of the span test is to set the upper limit of the weighing capacity of the conveyor belt scale to match the maximum capacity of the weighing application. The difference with the span test (versus the zero test) is the attachment of calibration test weight(s) to the weigh bridge(s) during the span test.

In the event that the design rate of your process changes, you can achieve the best accuracy by completing a new span test with more or less calibration test weights.

During the span test, the conveyor should be run to speed without material being loaded onto the belt with the calibration test weights attached.

Calibration test load methods

Typical calibration test weight designs include hand calibration test weights and calibration test chains, in addition to material tests. Hand calibration test weights are attached to the scale only during the brief completion of the span test and then stored until the next span test is performed. Hand test weights are universal, and one set of multiple hand test weights can be used across all belt scale(s) at the given site or regionally by all sites of a company.

Another option is to purchase an engineered calibration test chain for the belt scale. A calibration test chain looks like an oversized “bicycle chain.” Installation of a calibration test chain commonly includes a storage trough mounted above the conveyor and either a hand or electronic winch. The winch is used to lower the calibration test chain onto the conveyor belt to hold it stationary during the span test. The winch is then used to retrieve and store the calibration test chain in the trough until the next span test is performed.

A material test of the conveyor belt scale can also be completed where the weight produced by the conveyor belt scale is factored to another known weight. This known weight can be either a pre-weight, such as bagged material, or the unloading of a rail car or truck load of material across the conveyor scale.

Material that has been conveyed can also be collected in a truck or rail car and then weighed out on either a truck or rail scale. The conveyor belt scale can be factored to match the known weight of either the pre-weight or collected material to achieve the best accuracy.

Routine maintenance

Once the conveyor belt scale is properly installed and calibrated, proper routine maintenance will ensure proper operation. Since the conveyor belt scale will likely be located in a rather hostile environment, it is recommended that the user perform periodic checks whenever inspecting the conveyor or servicing other components in the area of the belt scale.

The conveyor belt scale should be kept clean of debris or spilled material. Heavy buildup of static material will register as weight on the scale and be added to the total on the integrator. This will produce a compound effect and can produce a high error in the accuracy of the belt scale over a long period of time. The scale idler(s) attached to the weigh bridge(s) and speed sensor should also be kept properly lubricated.

Wear and repair parts

The following parts of a conveyor belt scale are subject to a need for service due to wear and tear and, possibly, repair or replacement: integrator, weigh bridge, load cells, and speed sensor proximity switch.

The integrator is prone to potential failure due to issues with seasonal lightning if not properly grounded during electrical installation of the belt scale. Additionally, with a long cable run (i.e., between a conveyor and a control room) there is the opportunity for noise from wire interference (from anything that uses or produces power) to be introduced into the signal wires and affect the accuracy/operation of the scale.

The weigh bridge has additional electronics including junction cards, load cells, and failure potential for frayed wiring due to neglect. Additionally, the belt scale installation can suffer from problems as a result of a need for shimming/alignment of the scale weigh bridge and/or the idlers both before and after the scale. Some conveyor belt scale manufacturers require the idlers before and after the scale idlers to be shimmed.

Load cells are the devices which receive the force transferred by the conveyor idler supported by the weigh bridge. The force is then converted to an electrical signal that can be received by the integrator, which processes the signal as a load on the conveyor belt scale. Typical load cell designs for conveyor belt scales include both “shear-beam” and “S-type” load cells similar to beam and platform scales. The capacity of the conveyor in tons per hour will determine the load rating of the load cells commonly in 100-pound, 250-pound, 750-pound, and 1-kilogram capacities. A weigh bridge will use either one or two load cells. A multiple idler scale system consisting of multiple weigh bridges can use up to a total of eight load cells.

Speed sensors utilize electronic proximity switches and wiring in addition to mechanical wheels and greaseable bearing sets. Due to the mechanical nature of the speed sensor design, a catastrophic failure of a proximity switch may also require the replacement of a cog or counting wheel, in addition to a new proximity switch, to complete a repair of the speed sensor.

It is best to contact a manufacturer or local scale service company with your specific issues and further questions for their review and expert recommendation.

About the author: Austin W. Amos has 16 years of experience in the weighing industry and currently holds the position of general manager at ConveyWeigh, LLC., a West Virginia-based manufacturer of conveyor belt scales, and is an appointed member of the West Virginia District Export Council.

Ward Nye, president and CEO of Martin Marietta Materials, says in the MMM earnings report that “despite a continuing difficult operating environment,” he is pleased with the company’s performance.

“That we were able to increase prices and control costs is a credit to our operating teams and our disciplined approach to managing our business,” Nye says in a written statement about the earnings. “Specifically, in the quarter, aggregates pricing momentum continued with a 2.6% increase in the average selling price of our heritage aggregates product line. The quarter was, unfortunately, challenged by erratic weather as well as reduced spending on infrastructure projects. Therefore, as has been the case in the recent past, volumes were significantly lower, and that had an attendant negative effect on our operating profits. Our Specialty Products business continued its exceptional performance and established new quarterly records for both net sales and earnings from operations.”

NOTABLE ITEMS (ALL COMPARISONS, UNLESS NOTED, ARE WITH THE PRIOR-YEAR QUARTER)

– Earnings per diluted share of $0.78 compared with $1.18.

– Consolidated net sales of $426.7 million compared with $442.8 million.

– Heritage aggregates product line pricing up 2.6 percent.

– Heritage aggregates product line volume down 9.3 percent.

– Heritage aggregates product line direct production costs down 2.5%, despite a 13 percent increase in energy costs.

– Specialty Products record quarterly net sales of $49.6 million and earnings from operations of $19.3 million with a 380-basis-point improvement in operating margin (excluding freight and delivery revenues).

– Consolidated selling, general and administrative expenses down $1.9 million, or 20 basis points as a percentage of net sales.

– Consolidated earnings from operations of $63.0 million compared with $b90.7 million.

– Acquired an aggregates, asphalt and ready mixed concrete business in San Antonio.

By George H. Reddin

Merger and acquisition activity in the first quarter continues at a slow pace. The themes of balance sheet management, investment in emerging markets, and challenges in meeting the gap between buyer and seller price expectations continue to be visible in the construction materials sector. That said, earnings reports are starting to show modest increases in shipments with prices holding steady. These early signs of an improving market are good news for the mergers and acquisitions business and should lead to increased activity in the remainder of the year.

Recent transactions

Tarmac and France’s Lafarge have announced that they will merge their cement, aggregates, ready-mixed concrete, and asphalt operations in the United Kingdom (U.K.) into a new construction materials firm. The joint venture will have its own board of directors and will be led by an independent chairperson and executive management teams drawn from both businesses. Lafarge employs 2,800 people in the U.K. and supplies approximately 40 percent of the cement market, while Tarmac, the U.K.’s largest quarrying company, employs 4,500 people and operates 118 quarries, 69 asphalt plants, and 180 ready-mixed concrete sites. Tarmac has been for sale since 2007 and still plans to exit U.K. construction materials and sell its interest in the joint venture.

George H. Reddin is a principal in FMI’s Investment Banking practice. He can be reached at 919-785-9286 or at greddin@fminet.com.

Oldcastle Materials, Inc. announced that APAC-Texas Inc. acquired the assets of two independent sand and gravel companies operating in Austin, Texas. Oldcastle acquired three sand and gravel plants from Shumaker Enterprises, Inc., and one location from Austin Reclaimed Materials.

Other news

Cemex has swapped bonds due in 2020 for some of its outstanding perpetual debentures to cut its debt load, which will reduce its total liabilities by $41 million. Cemex must reduce debt by $2.3 billion this year to avoid a $200 million jump in its annual interest costs under the terms of its financing agreements.

Martin Marietta Materials, Inc. exceeded expectations with a fourth quarter profit of $14.8 million, compared to a loss of $3.2 million during the same period of the previous year. The fourth quarter results were impacted positively by a 14-percent increase in heritage aggregates shipment.

Vulcan Materials Company announced that it lost $47 million in the fourth quarter; however, trailing 12-month aggregates shipments have increased modestly since February of last year.

By Tom Nenne

Steel tracks are designed to perform in tough underfoot conditions, but long hours in wet, muddy, slippery, rocky, or abrasive materials can translate into rapid wear and high repair costs. The undercarriage on a large dozer can account for 50 percent of the repair and maintenance costs for the machine — even when the operator and maintenance personnel use best practices.

When mud and debris build up under your machine, components wear at a faster rate, so don’t begin work until the undercarriage area is clean.

Abrasive wear is the primary type of wear experienced by undercarriages, which is impossible to avoid in aggregates operations. But the operator can take a number of steps to maximize service life and drive down operating costs, and service personnel can ensure that undercarriages don’t experience excessive wear due to maladjustment. Frequent and proper inspections also can avert premature failures, which result from little problems growing into big ones.

Long before your dozer or excavator goes to work, you will make decisions that influence undercarriage wear and subsequent maintenance costs. A number of different track designs are available now. Though the most wear resistant have higher initial cost, selecting such an undercarriage often results in lower life-cycle costs. Generally speaking, the more you work in high-horsepower, high-torque applications, the faster your undercarriage will wear. Work with your equipment dealer to select the undercarriage design that is best suited to your site conditions and application.

Watch your speed. To achieve maximum productivity with a dozer, remember: Big load, slow.

One rule of thumb applies to all undercarriage designs, however. Always use the narrowest track shoe possible that meets your flotation requirements. Wide shoes operating on hard surfaces put tremendous strain on the shoes, pins, and bushings. The result is accelerated wear.

Also, if you work in very sticky materials, consider using center-punched track shoes to reduce material packing in the undercarriage area when specifying undercarriages. To further limit material packing and debris buildup, use roller guards only when necessary. They’re designed for high-impact underfoot conditions.

Tips to extend undercarriage life

1. Start every shift with a clean undercarriage. When mud and debris build up on the lower part of your machine, components wear at a faster rate, so don’t begin work until the undercarriage area is clean. If a cleanup didn’t happen at the end of the previous shift, take a few minutes to get the job done before you go to work. And if you’re operating in very cohesive or abrasive materials such as mud or clay, you may need to clean the undercarriage more than once during a shift.

Don’t spin your tracks, as it accelerates undercarriage wear. Grouser bars are especially prone to wear problems associated with track slippage.

2. Inspect the undercarriage before you start working. In addition to ensuring that the undercarriage is clean, spend a couple of minutes on a visual inspection. Check for loose bolts, leaky seals, and abnormal wear patterns. When you spot potential problems early, you can often prevent them from turning into bigger issues that significantly reduce component life or cause unscheduled downtime.

3. Don’t spin the tracks. Track spinning delivers several hits to the bottom line. It reduces production, so your revenue potential declines. It increases fuel consumption, without a corresponding increase in productivity. And, it accelerates undercarriage wear, so your costs escalate. Grouser bars are especially prone to wear problems associated with track slippage.

Tight track is the number one track killer.

4. Watch your speed. There are times when a task requires higher speed operation, but wear accelerates as speed increases. Links, rollers, and idlers are particularly vulnerable. Keep them working longer by controlling your speed. The mantra for dozer operators to achieve maximum productivity in production dozing is: Big load, slow.

Service personnel can ensure that undercarriages don’t experience excessive wear due to maladjustment. Frequent and proper inspections also can avert premature failures, which result from little problems growing into big ones.

5. Avoid unnecessary reverse operation. Operating in reverse, even at slow speeds, compounds bushing and sprocket wear. So don’t run in reverse unless you have to. To avoid spending more time in reverse than necessary, aim for pushing large loads in first gear.

6. Alternate turning directions. If you’re always turning in the same direction, the undercarriage components on one side of the machine will wear at a different rate than those on the other side. More specifically, turning left all the time accelerates wear on the right side and vice versa. To ensure even wear, pay attention to the way you’re turning and change directions when possible.

7. Work up or down a slope whenever possible. Working across a slope can shorten undercarriage component life, so try to structure the job with minimal cross-slope activity. Also, dozing downhill achieves greater production with less fuel burn by using gravity to your advantage.

8. Avoid galling. Galling is caused by loss of lubricant between pins and bushings in the track caused by excessive pressure pushing oil past the seals. A combination of excessive load and speed, running track tighter than specified, packing conditions, and the practice of “mud flinging” all can cause galling. Mud flinging involves raising the dozer up with the ripper and blade and rotating the tracks.

9. Always dig over the front idlers to reduce the potential for structural problems. Specific to excavator operators, never dig over the final drive, and never dig over the side of the machine.

Maintenance means inspection, tensioning, cleaning

Maintenance discipline plays a big role in undercarriage component life. Conduct a visual inspection daily or when underfoot conditions change significantly. Check track adjustment; check for oil leaks on links, rollers, and idlers; and look for broken or loose undercarriage components and excessive gaps between track shoes.

One of the most critical maintenance practices is track adjustment. Tight track is the number one track killer, but whether your track is too loose or too tight, improper adjustment accelerates wear. Follow the manufacturer’s recommendations for track adjustment, and always perform the adjustment in the machine’s working environment.

As noted earlier, cleaning the undercarriage maximizes wear life. The task may be the operator’s duty or it may be the duty of maintenance personnel. Regardless, remove mud and debris at the end of every shift, or more frequently if necessary.

Many aggregates operations rely on their equipment dealer to periodically inspect and measure undercarriages. For example, the Cat Custom Track Service provides reports with maintenance and repair alternatives that the aggregates operation can select to achieve lowest cost of operation.

Getting the most from your dozer and excavator undercarriages is a matter of good operating techniques and diligent maintenance attention. Doing that right means longer lives for your undercarriages and lower costs for your mine. AM

Tom Nenne is senior product support consultant, Caterpillar Inc.

Sales in the second quarter of 2010 were 344,000 tons generating revenue of $4.72 million, compared to sales of 487,000 tons and revenue of $6.22 million in the comparable prior year quarter. Sales for the first six months of 2010 increased by 3.9 percent to 720,000 tons compared with sales of 693,000 tons for the prior year with revenue increasing by 5 percent to $9.61 million from $9.14 million in 2009.

Underlying prices for the company’s construction aggregates products, net of fuel cost adjustments, remain stable.

For the news release and more details on the financial results from Polaris Minerals, click here.

The report, released the week of March 29,  shows that – after a 26 percent increase in the number of inspectors hired by the agency – more than a quarter of inspectors were not receiving the training needed to properly enforce safety and health standards. 

MSHA even authorized one person to perform inspection duties without having been required to complete the minimum, entry-level requirements. Furthermore, the MSHA Academy – where inspectors are supposed to receive their training – lacked timely and adequate support documentation for some training, the National Stone, Sand & Gravel Association (NSSGA) reports in its Washington Watch e-newsletter.
 
The report, which covered the training cycle from 2006 to 2007, went on to recommend a number of actions, including the following:
• implementation procedures and controls to hold supervisors accountable for assuring that all journeyman inspectors complete required, periodic training;
• revise training policy to suspend an individual’s health and safety inspection activities if designated retraining is not completed as required;
• re-emphasize to all personnel MSHA’s training requirements; and  
• develop and implement written policies and procedures to justify and document cases in which completion of minimum requirements are waived.

NSSGA says it’s worth nothing that in NSSGA CEO meetings with the agency’s leaders appointed by President Obama, the association says it forcefully advocated that training be improved resulting in more consistent and risk-based enforcement. 

MSHA’s Assistant Secretary Joe Main has indicated that improved training is a high priority. NSSGA’s Safety and Health Committee is working to identify areas of ambiguity in current law, regulation or guidance, according to NSSGA.

Check out the AggBeat news section in the June 2010 print edition of Aggregates Manager for a more detailed report on this — or come back to this site to see the report in the Aggregates Manager June 2010 digital edition.

“We are excited about the advanced level of engineering competence Rockland has to offer our customer base – this will be a true complement to our manufacturing capabilities,” Valley Rubber President Cronan Connell, said in a written statement.

In addition to expanding the engineering services of Valley Rubber, Rockland will continue to serve and develop its own client base.

“We are so energized and enthused to have become a part of Valley Rubber, a dynamic company. The character and convictions of their owners are of the highest caliber, and are an inspiration to us all.” said Brent Guddat, president of Rockland International, in a press release.

Bell is in charge of progressing current national accounts and creating new agreements that mutually benefit both parties in North America and globally. This is his second stint with Major Wire, serving as the company’s Western U.S. Territory Manager from 2003 to 2005.

More recently, Bell comes from Encore Metals of Seattle, Wash., a division of Reliance Steel — the largest U.S. distributor of steel products. Before joining Major Wire in 2003, Bell spent more than 10 years in the aggregate and recycle markets as the Manager of Aggregate Sales for Tramac Corporation and as the Director of Key Account Sales for Ramco Construction Tools.

“Richard understands the needs of aggregate, recycle and coal operations today and already has valuable relationships with many of the largest, most respected producers,” said Major Wire’s Vice President of Sales Gary Pederson in a press release.

As a result of this purchase, the Polymer Division was created.  Investment is now proceeding to expand this operations capability.  The Polymer Division of McLanahan Corporation has officially become the 6th Operating Division among the many diversified industries that we now service.

Currently, the Polymer Division is operating out of Lakeland, Florida, and continues its manufactured sales of products into the traditional southeast mining environment along with the addition of many wear components used by the McLanahan Aggregate Processing Division. 

These components include sizing & dewatering screen panels, screw washer shoes, sand classifier valves, seats, downspouts, chute liners, impact pads, log washer paddles, cyclone liners, and vortex finders; along with trommel screens, paddles, lifters, and restrictors.

McLanahan says that it will supply its companies’ internal needs, but it also plans to supply other markets both domestic and foreign, which has begun with the company’s distribution into Latin America.  

 “We are very excited to increase our product offerings to our customers and expand our opportunities for the future.  The Polymer Division will also allow us to become a more vertically integrated company,” said Sean McLanahan, vice president of McLanahan Corp., in a written statement.