Big Trenchers Ready For Tough Jobs
Published in: Construction Equipment
Date: 9/1/2001
By: LANDBERG, LYNN
Even solid rock is no match for a large trencher suited to the right application
To coin a phrase: When the going gets tough, the big trenchers get going. At a time when the spotlight seems to be on horizontal directional drilling and the question is often asked if directional drills will replace trenchers, the answer is no when it comes to straight-line trenching in rock, through concrete or hardpan. Nor is the hydraulic excavator always the trencher of choice under these conditions.
Large trenchers, in this case defined as those of more than 100 horsepower, can beat an excavator on trenching long, uninterrupted runs, and the trencher can dig narrow trenches for pre-assembled pipe, creating less spoil. Plus, the trencher can dig deeper than an excavator if equipped with an extra-long trench chain attachment. Factors as to where a large trencher or excavator works best include the material being installed, whether the trench must be large enough to accommodate workers, existing surface improvements, digging conditions and underground utilities already in place.
But today’s large trenchers have been made more versatile to handle a variety of trenching challenges and are not necessarily restricted to long-run trenching. In addition, many big trenchers can handle attachments such as rock saws and vibratory plows. They’ve also been equipped with controls that provide trenching accuracy and constant depths. With the larger trenchers, custom modification is common, with most manufacturers willing to meet customer needs on an individual basis. Although only a small number of companies manufacture larger trenchers, those that do have something to talk about.
Largest trenchers
Trencor makes some of the largest trenchers around, and one of its largest models is the 1660HD mechanical drive chain trencher. It’s powered by a 750-hp Caterpillar engine and can be equipped with Trencor’s RoadMiner attachment, replacing the chain trencher. The RoadMiner turns the trencher into an excavator for bulk excavation, quarry operations and surface mining.
With the chain trencher attachment in place, the 1660HD has trench depths of 8 through 25 feet and trenching widths from 14 to 60 inches. The digging chain drive consists of a headshaft that is driven from both sides by a roller chain arrangement directly behind a heavy-duty Caterpillar differential, which is powered by an Allison powershift transmission with integral three-element torque converter.
Trencor touts its mechanical-drive power train, noting that hydrostatic drives, although popular, lose power due to heat, have inefficiencies with hydraulic pumps and motors, and are complex. Trencor says its mechanical drive provides increased torque, increased productivity, broader range of chain speeds, reduced fuel costs, ease of repair, lower repair costs and longer machine life.
Although usually associated with smaller trenchers, Ditch Witch nevertheless produces a hefty machine in the form of the RT185/HT185. The RT model rides on rubber tires, while the HT is a track trencher. Both are powered by a 185-hp engine and can be fitted with a trencher attachment, traversing saw and vibratory plow. All can be offset for work in tight areas. The operator’s seat swivels to 45- and 90-degree angles, with easy-to-reach controls being color-coded for quick identification.
The machine, when equipped with the chain trencher attachment, can dig to a depth of 84 inches. The vibratory plow reaches to 48 inches, and the saw cuts to depths of 42 inches.
Ditch Witch’s other entry in the big trencher category is the 8020T, a rubber-tired machine that is a turbocharged version of the standard 8020, providing a 30-percent increase in power. Several attachments are available for the 8020T, including a trencher, traversing trencher, combination trencher and vibratory plow, backhoe and saw.
Large pipe installation
The newest machine in Vermeer’s trencher line is the T-1255 Commander, its largest rock trencher. The unit is designed for installing large-diameter pipe for contractors in the energy pipeline business or deep sewer and water applications. With 600 horsepower and weights up to 185,000 pounds, key features of this machine include dual headshaft motors and a thermostatically controlled oil cooler. In addition, the T-1255 is equipped with Vermeer’s TEC 2000.2 computeraided control system, a microprocessor-based electronic control system that integrates separate, stand-alone components into fewer, simpler controls. An exclusive feature of the new TEC 2000.2 is Auto Plunge. With the flip of a switch, operators are able to engage the automatic plunge cutting feature to reduce the number of manual adjustments as well as decrease chains stalls and engine kills. The system automatically adjusts the trencher to varying conditions with minimal need for operator input. It also monitors trenching operation and records m achine-system conditions to simplify service and maintenance.
Among other features of Vermeer’s largest trenchers is the cab design. Selected Vermeer trenchers have premium elevating cabs that adjust to the operator’s preference for a better view of the work in progress. On some other units, a double-cab design provides two operator positions with a swivel panel to make control of offset trenches easier. In addition, climatized cabs keep the operator comfortable and provide visibility for better control and inspection of digging operations.
A major supplier of European trenching equipment is Northland Trenching, representing the Dynapac and Inter-drain lines. Its newest model is the Inter-drain 1622HT chain trencher. Northland points out that this compact unit has the same performance features as the larger models, but is packaged into a smaller configuration. The unit weighs approximately 25,000 pounds and is powered by a 220-hp engine, yet has an overall width as narrow as 81 inches. Options include a conveyor to load from either side and trencher offset.
Not all large trenchers are chaintype units. Case in point is Guntert & Zimmerman, which produces five wheel trenchers. The Eagle line of trenchers can be used in a wide variety of applications, including foundations, utilities, irrigation and fiber-optic installations. While the trencher digging wheel is mechanically driven for maximum transfer of horsepower, all other machine functions are hydraulic. The largest trencher, the 8300, is a trapezoidal unit that can dig a trench to 8 feet deep and 6 feet wide. It’s powered by a Caterpillar 3306B DITA engine rated at 400 horsepower.
From RWF Industries comes the Bron AKT-5 Scissor Plow/Trencher. It uses a vibratory plow to trench to 60 inches deep and plow in 10-inch lines or a trench 18 inches wide. According to RWF, the trencher can exceed speeds of traditional trenchers in most types of soil. With few moving parts, the unit uses oscillating dual blades that cut through the ground. Depending on which chute is used, the trencher can leave the ground closed or have the dirt piled on either side of the trench. The AKT-5 consists of a Bron 150 crawler dozer, a self-propelled utility tractor that is hydrostatically powered with independent left and right track controls.
Basic Specifications
Trenchers[greater than]100 hp
Campany/ Max. Digging Max. Digging
Model HP Depth Width (in.)
Ditch Witch
8020T 106 7’3″ 24
RT185 175 7′ 24
HT185 175 7′ 24
Guntert & Zimmerman
Eagle 5500 105 5′ 24
Eagle 8300 400 8′ 72
Eagie 7500 300 7′ 39
Eagle 4500 105 4′ 24
Eagle 7300 300 7′ 60
Northland Trenching
Dynapac 3000 267 6’7″ 11
Dynapac 3600 348 19’8″ 12
Dynapac 2000 213 6’7″ 11
Inter-Drain 1520 HRT 192 3′ 20
Dynapac 527 348 11’6″ 24
Dynapac 525 316 9’3″ 22
Inter-Drain 7060 HT 677 11 ‘6″ 24
Inter-Drain 3035 HT 422 7′ 20
Dynapac 1800 152 6′ 9
Inter-Drain 2028 HRT 276 5′ 20
Inter-Drain 6050 HT 520 9,9″ 24
Trencor
1080 750 9’6″ 84
860B 300 4′ 12
1460HD 600 16′ 48
760HD 210 8′ 28
960HD 325 10, 36
1260HD 402 12′ 42
665HD 185 8′ 24
700C 402 6’6″ 78
660B 250 4′ 10
1460HD 600 4′ 150
Campany/ Operating
Model Weight (lbs.) [*]
Ditch Witch
8020T 6,800
RT185 16,000
HT185 20,000
Guntert & Zimmerman
Eagle 5500 24,400
Eagle 8300 95,000
Eagie 7500 54,868
Eagle 4500 22,445
Eagle 7300 75,000
Northland Trenching
Dynapac 3000 33,500
Dynapac 3600 44,100
Dynapac 2000 31,520
Inter-Drain 1520 HRT 30,000
Dynapac 527 52,920
Dynapac 525 48,500
Inter-Drain 7060 HT 99,000
Inter-Drain 3035 HT 48,400
Dynapac 1800 24,900
Inter-Drain 2028 HRT 40,000
Inter-Drain 6050 HT 81,400
Trencor
1080 235,000
860B 65,000
1460HD 185,000
760HD 50,000
960HD 85,000
1260HD 125,000
665HD 36,000
700C 75,000
660B 46,000
1460HD 175,000
1760HD 900 20′ 72 375,000
1260RS 525 4’6″ 12 90,000
1860HD 1,500 35′ 96 450,000
1000C 750 12′ 120 170,000
800C 502 8′ 104 95,000
500C 300 5′ 60 55,000
1460D 503 14′ 48 110,000
1030D-400 402 12′ 36 55,000
1030D-300 300 10′ 24 45,000
1660HD 750 5′ 150 225,000
1660D 750 18′ 60 150,000
930HD 325 9′ 72 100,000
1260HD 402 3′ 120 135,000
Vermeer
T-1455 657 20′ 54 180,000
T-1555 700 20′ 56 180,000
T-1055 400 14′ 48 115,000
V-120 116 5′-6′ 18 7,158
T-555 140 8′ 24 22,500
T-955 360 12′ 42 95,700
T-855 335 12′ 36 86,000
T-758 250 6′ 24 67,000
T-755 250 10, 36 66,000
T-658 180 4′ 20 56,000
T-655 DT 250 8′ 24 43,000
T-555 DT 185 8′ 24 23,000
T-455 125 6′ 24 18,000
T-655 200 8′ 28 42,500
(*)Operating Weight:
Tractor weight only
47 – Number of trencher models over 100 horsepower currently available. Some trencher manufacturers build large trenchers to customer specifications, so the actual number of trencher models would exceed this number.
5 – Number of new trencher models in the over-100-horsepower category introduced in the past 12 months.
$150-$500,000
Approximate price range of trenchers over 100 horsepower, based on limited information. Prices could vary beyond these parameters due to options and custom designs.
Summary Box
Large trencher features emphasized by manufacturers:
* Attachment availability.
* Customization based on customer’s needs.
* Heavy-duty construction.
* Availability of options.
* Versatility.
* Comfortable cabs.
* Visibility.
* High-tech controls.
* Horsepower reserve for difficult conditions.
*Source: “Contractors’ Equipment cost Guide,” published by Equipment Watch (formerly Primedia Information): tolephone: 800/669-3282.
COPYRIGHT 2001 Reed Business Information