In an age when strip malls can be measured in miles and the pace of commercial development can forestall the economic impact of a significant housing downturn for more than a year, improving the productivity of paving parking lots and streets has become a priority. New-machine introductions over the past six months by five of the seven paver manufacturers with machines weighing between 15,000 and 40,000 pounds suggests that a lot of commercial paving is challenging traditional boundaries of the machine category.
"We've always limited ourselves — and AEM (Associated Equipment Manufacturers) has even classified — 19,000 pounds as being the top of the commercial paver class," says John Hood, manager of product development and sales for Bomag's paving and milling products. "Typically what we've always done as commercial paver manufacturers is try to stay below 16,000 pounds. Once you exceed that weight, you're required to add fume-extraction systems."
Carlson decided to enter the complete-paver business at less than 19,000 pounds. The industry's only aftermarket screed manufacturer showed its CP-90 at Conexpo-Con/Agg 2008. The prototype on the show floor weighed 20,000 pounds, but Carlson marketing manager Tom Trivers promised production models due late this year would hit the streets at about 18,500 pounds.
"Most commercial-paver customers want to be able to put a small paver and one or two rollers on one trailer," Trivers explains. "With equipment like that, sometimes they can finish a couple of projects in a day."
Of course, Carlson developed a completely new electrically heated screed for use exclusively on the company's first paver, but Trivers insists that a lot of engineering time was spent fitting a robust material-handling system to the commercial machine.
"We want to offer a small commercial machine that's completely rebuildable," he says. "So we adapted the conveyor chains, slats and augers out of a 10-foot Roadtec paver for this application."
Look for Carlson's CP-90 to be available in the third or fourth quarter of 2008, at a suggested retail price of about $150,000.
In 2004, the 25,000-pound LeeBoy 8816 penetrated deep into a weight class where the few paver options were all built by makers of highway-class machines. Now the Volvo PF161 and PF2181, the Terex CR352, and Volvo Titan 3870 are also vying for the 150 or so sales per year in the 20,000- to 30,000-pound range.
"Commercial pavers may show up on a jobsite with the paver, the roller, all the plates, and the hand tools all on one truck, but there is a segment of the industry that has evolved beyond that," says Bomag's Hood. "When you start talking about 20,000-pound machines, the transportation costs change tremendously. By the same token, the compaction tools that you see behind this size machine are larger so you can't really put the paver and the roller on one trailer anyway."
Bomag stepped over the 19,000-pound threshold with a 20,500-pound model introduced at Conexpo, the BF6615.
"It does change the classification of the contractor somewhat, but what you trade off with that (heavier machine) is an increase in productivity," Hood continues. "In the case of the 6615, twice the productivity of any other machine we offer, plus improved mat quality."
Bomag's track-mounted BF6615 comes with the company's first electrically heated screed and independently controlled, reversible conveyors and augers to refine control of the head of material in front of the screed. The Mega-Feed system mounts remote augers on the front of the screed extensions. The augers extend and retract with the extensions and refine control of material all across the screed. Digital grade control is easily integrated to the electronic-over-hydraulic control schemes.
Bomag's commitment to preventing paver downtime led the company to install dual redundant, all-hydraulic control panels on both rear corners of the tractor. These alternate operators' panels are below the seats for the normal operating stations. Bomag's message might be paraphrased: 'We're not expecting problems with our electronics, but if manual controls reassure skeptical customers, we can squeeze an extra set of levers on the paver.'
One of the defining features of the BF6615, and all of today's plus-sized commercial pavers, is a heavier material-handling system designed to be easily rebuilt. Hood points to the 6615's bolt-on, 400-Brinell hardened steel screed plates and replaceable auger flighting.
The BF6615 goes head-to-head with the Volvo PF161 (a Blaw-Knox model carried over from Volvo's purchase of the Ingersoll Rand Road Construction Group), which is a wheeled machine with diesel-heated screed choices.
The BF6615 weighs 5,000 pounds more than the next model in Bomag's line, and LeeBoy's 8816 with electric screed is about 5,000 pounds heavier than the BF6615. The tracked 8816, at 25,000 pounds and 130 horsepower, sits alone in a gap bordered on the low end by the big Bomag and Volvo's PF161, and the Volvo PF2181 at 27,650 pounds and 158 horsepower on the high end.
All four are eight-foot machines, but it may be indicative of the difference between up-sized commercial pavers and down-sized highway pavers to note that screed widths of the Bomag and LeeBoy hydraulically extend to 15 feet and 15 feet 6 inches, respectively. Widths of the PF161 and PF2181 stretch to 19 and 21 feet. It would be hard to support any definitive conclusions from such a comparison, but it does suggest that there is a transition here in the mid-20,000-pound range from what has traditionally been known as a commercial-class machine, and eight-foot pavers that are also being spoken of as "commercial class."
Eight-foot machines range up to Cat's brand new AP600D and AP655D, which exceed 40,000 pounds when equipped with the heaviest of their screed options. Until LeeBoy's 8816, this range of machines had been the exclusive territory of highway-class paver manufacturers.
Once again demonstrating its ambition, LeeBoy introduced a 33,000-pound wheeled paver at Conexpo. The 9000 pits LeeBoy's electric Legend screed head-to-head against wheeled pavers from Vögele and Caterpillar.
Half of the 14 asphalt-paver models arrayed between 25,000 and 40,000 pounds are brand new, or significantly upgraded in the past six months. Highway-class features are becoming common, and sophisticated upgrades are readily available. Terex 300-Series pavers, for example, both use the same conveyor slats and chains as the highway-class 400-Series machines.
Separate conveyor and auger drives, which can be adjusted to fine tune the flow of material to the screed, are fairly universal. With individual drive and material monitoring for each conveyor and each auger, mix can be spread in the auger tunnel while conveyors are stopped. Conveyance and spreading can be run fully automatic so the paver operator can focus elsewhere, or the system can be run completely manual. Such finite control of the conveyance has made the flow gates obsolete on many machines.
Electric screed heat is coming to dominate pavers in this size class. Uniform heating across the entire screed, reduced fumes, and increased reliability of modern electric heating systems offer benefits that are hard to ignore.
Three of this year's new paver introductions employ controller area network (CAN) bus systems for managing the on-board electronics. It is a digital technology that can significantly improve wiring-harness reliability. LeeBoy's 8816 has been a CAN-bus-controlled paver, and the 9000 uses the same type of system. Vögele's 8-foot Vision pavers and the Caterpillar AP600D and AP655D also integrate CAN bus systems.
This automotive-style design distributes computing power to each of the devices on the paver that relies on digital input or provides digital information. A single wire connects all of the computers on-board. This electronic approach is facilitating use of digital gauges and sophisticated electronic diagnostics on the new LeeBoy, for example. The CAN bus also allows what LeeBoy calls Plus 1 steering control with dual joysticks.
Even with the CAN bus' promise of simplified wiring, there are those who fear downtime with digital technology's application to an asphalt paver. Of course, that represents a marketing opportunity.
"The paver industry seems to be moving toward larger and more expensive units with high-tech features," says Steve Kirst, Gehl paver product manager. "It is important for the Gehl Company to continue to serve the market sector that is looking for the simple to operate, easy to service, more compact pavers."
So there appears to be room for all kinds of paver design in today's stretched commercial-paver market.
|The Cost of Ownership|
|Weight||List Price Track/Tire||Hourly Rates Track/Tire|
|Hourly rates start with monthly ownership cost divided by 176 (hours per month) and add hourlyoperating cost. Inputs used to derive the costs include diesel fuel at $3.38 per gallon, mechanic's laborat $44.79 per hour, and interest rate of 4.75 percent.|
|Source: "Contractors Equipment Cost Guide," published by Equipment Watch - (800) 669-3238|
|25,000 to 34,999 pounds||$341,143/$319,713||$196.84/$177.65|
|OperatingWeight* (lb.)||Basic Screed WidthMin.||Max.||HopperCap. (tons)||EngineHP||TransportWidth*|
|* With basic screed|
|All models are track mounted unless designated ″Tire″|
|Salsco 5013||3,060||3′ 0″||6′ 0″||—||10||4′ 0″|
|Puckett 540||7,000||8′ 0″||12′ 0″||4||28||8′ 6″|
|Neal 5500||7,200||5′ 3″||8′ 3″||4||38||5′ 3″|
|Gehl 1448||7,775||8′ 0″||12′ 0″||4||36||8′ 5″|
|Puckett 560||8,250||9′ 0″||13′ 0″||6||38||9′ 9″|
|Mauldin 550E Track/Tire||8,300/7,800||8′ 0″||13′ 0″||5.5||23||8′ 5″|
|Mauldin 690F Track/Tire||9,700/9,300||8′ 0″||13′ 0″||6||38||8′ 5″|
|Puckett 580||10,000||8′ 0″||13′ 0″||6.5||38||8′ 6″|
|Bomag 3313||10,000||8′ 0″||13′ 0″||6||50||8′ 6″|
|LeeBoy 1000F Track/Tire||10,000||8′ 0″||13′ 0″||5.5||37||8′ 6″|
|LeeBoy 700F Track/Tire||10,000||8′ 0″||12′ 0″||5.5||37||6′ 6″|
|Gehl 1648||10,600||8′ 0″||13′ 0″||6||48||8′ 6″|
|Vögele Super 700||11,685||3′ 8″||10′ 6″||5.5||57||9′ 5″|
|LeeBoy 5000||12,000||5′ 0″||9′ 0″||5||37||5′ 6″|
|LeeBoy 7000||12,000||8′ 0″||13′ 0″||6||56||8′ 6″|
|Mauldin 1500 Track/Tire||12,300/11,800||8′ 0″||13′ 0″||6.5||50||8′ 4″|
|Mauldin 1550-C||12,500||8′ 0″||13′ 0″||6.5||60||8′ 6″|
|Bomag 814||15,400||8′ 0″||14′ 0″||8||85||8′ 6″|
|Bomag 4413||15,500||8′ 0″||13′ 0″||7.5||60||8′ 6″|
|Bomag 815||15,700||8′ 0″||15′ 0″||8||85||8′ 6″|
|LeeBoy 8500||15,700||8′ 0″||15′ 0″||7.5||74||8′ 6″|
|Mauldin 1750-C||15,700||8′ 0″||16′ 0″||8||80||8′ 6″|
|LeeBoy 8515||15,900||8′ 0″||15′ 0″||7.5||74||8′ 6″|
|LeeBoy 8510||17,200||8′ 0″||15′ 0″||7.5||85||8′ 6″|
|Carlson CP-90||18,800||8′ 0″||15′ 0″||—||84||8′ 6″|
|Blaw-Knox Volvo PF161 Tire||20,350||8′ 0″||19′ 0″||9.8||107||8′ 3″|
|Bomag BF6615||20,500||8′ 0″||15′ 0″||9||99||8′ 6″|
|LeeBoy 8816||25,000||8′ 0″||15′ 6″||10||130||8′ 6″|
|Blaw-Knox Volvo PF2181 Tire||27,650||8′ 0″||21′ 0″||11||158||8′ 2″|
|Terex Cedarapids CR352 Tire||28,760||8′ 0″||18′ 0″||9||165||8′ 8″|
|ABG Volvo Titan 3870||28,880||6′ 7″||16′ 5″||13.2||99||9′ 9.7″|
|Terex Cedarapids CR362||31,450||8′ 0″||18′ 0″||9||165||8′ 6″|
|Blaw-Knox Volvo PF4410||31,500||8′ 0″||25′ 0″||8.5||158||8′ 2.5″|
|Vögele 5103-2 Tire||31,700||8′ 0″||13′ 6″||12||170||8′ 4″|
|Vögele 5100-2||32,600||8′ 0″||13′ 6″||12||170||8′ 4″|
|LeeBoy 9000 Tire||33,000||8′ 0″||15′ 6″||11||173||8′ 6″|
|Barber-Greene BG-230D Tire||35,310||8′ 0″||20′ 2″||—||130||8′ 8″|
|Caterpillar AP800D Tire||35,310||8′ 0″||20′ 2″||—||130||8′ 8″|
|Roadtec RP 170 Tire||36,500||8′ 0″||15′ 6″||11||174||8′ 6″|
|Caterpillar AP600D Tire||37,251||8′ 2″||14′ 5″||—||174||8′ 5″|
|Roadtec RP 175||38,800||8′ 0″||15′ 6″||10||174||8′ 6″|
|Caterpillar AP655D||39,727||8′ 2″||14′ 5″||15.5||173.5||8′ 11″|
|Terex Roadbuilding||Vögele America|