How do manufacturers rate Htheir own drifters? By impact Henergy? If so, is that figure calculated or is it measured? Manufacturers that recommend a particular drifter for a given hole diameter may have the right idea. After all, the drill steel can only take so much energy. But how do mine operators rate drifters? Do they look at penetration rates for a given hole size under certain ground conditions? And is this rating system compatible with that of the manufacturers? These are some of the questions to keep in mind while shopping around for a single-boom jumbo to meet mine development needs. Atlas Copco Canada
This company was one of the first manufacturers of 1-boom jumbos to tackle the Canadian market. It sold its first to Cominco's Sullivan mine in 1976, says Paul Bertrand, product manager of underground equipment.
The company has three different drifter models to choose from. Each is suited for a particular carrier/boom design. Depending on the size of heading, the number of holes to be drilled per round and the time available to drill a single drift round, Atlas Copco recommends one of its three drifters. The COP 1032 (7.5-kw) drifter is suited for drilling 1.5-inch-diameter holes, the COP 1238 (15-kw) drifter for 1.75-inch-diameter holes and the COP 1440 (22-kw) drifter for holes measuring 1.75 or two inches in diameter. The COP 1238 can also be used to drill 1.5-inch-diameter holes. But an adjustment is required so that the drifter performs at a reduced output.
The 151-kg COP 1440 is a relatively new drifter. It has been available in Canada for less than one year. Two units have been sold to a single mine so far, Bertrand says. The high energy output (22 kw at 60 to 70 hz) of the COP 1440 translates into high penetration rates, which can be advantageous to mine operators. One of these drifters on a 1-boom jumbo can achieve the same d rilling productivity as two smaller drifters on a 2-boom jumbo, Bertrand says. What follows are some of the advantages of using a flexible, 1-boom unit (that can reach all holes on a given face area) over a 2-boom unit:
* better accessibility in narrow openings;
* no boom "dead time," i.e. there is not another boom sitting idle while the operator positions the boom for another hole; and
* there is more room in a narrow heading for surveyors, geologists and maintenance personnel.
Atlas Copco's booms feature a telescopic feed, auto-parallelism and 360 degrees rotation. After drilling a drift round using 12- or 14-ft drill steel, the boom can be retracted to drill 6- or 7-ft holes in the back for installing rock bolts.
The company's 1-boom jumbos are assembled in Montreal. Booms, feed and drifters are manufactured in Sweden, and Getman carriers from the U.S. are often (though not exclusively) used. Crawler or rail-mounted options are also available. Circle Reply Card No. b Boart Canada
Boart Canada has entered the 1- boom jumbo market with two models. The company's new Minimaster jumbo features a newly-developed boom giving an auto-parallel face coverage of 10 sq m, says Ivan Vaklamoff, product manager for North American sales in Lebanon, Pa.
Any one of the company's four HD series drifters (HD-65, HD-75, HD-80 or HD-125) can be used on the new rig, which comes equipped with Boart's BDS-F-5000 series feeds. The larger, Tunnelmaster R341 single- boom jumbo is designed for the company's HD-125 hydraulic drifter. This unit is equipped with a BDS-70 1600 U boom which maintains parallelism in all drilling planes regardless of carrier orientation. The HD 125 rock drill is recommended for hole sizes ranging from 41 mm to 95 mm in diameter. The Tunnelmaster features a Deutz F6L 912W 6-cylinder diesel engine mounted on a Minejack M40P carrier complete with a Clark transmission coupled to a Clark torque converter.
The Minimaster carrier features 4- and 2-wheel drive and a crab steering mode for a high degree of manoeuvreability in small mine openings and comes equipped with a Deutz 4- cylinder diesel engine rated at 37 kw.
The new BDS-B-12 Miniboom is a fixed-length boom constructed of cast iron components and adjustable pivot pin assemblies. The boom is capable of 360 degrees rotation.
An aluminum alloy extrusion feed frame, designed to accept hollow stainless steel wear rails, is the core of Boart's BDS-F-5000 series feeds. The rock drill feed is provided by a hydraulic cylinder and wire rope arrangement, giving a feed thrust of 10 kn.
To support the drill bit during collaring, the unit features urethane rubber guides available in various sizes. Circle reply card No. * Continuous Mining Systems
Continuous Mining Systems of Sudbury, Ont., builds two single- boom jumbo models -- the CJ-1H and the CDJ-1H. This company picked up the Canadian marketing rights for France-built Montabert drifters about two years ago.
The CDJ-1H jumbo is built around the Montabert HC-40 low-profile, hydraulic drill with variable rotation and hydraulic percussion while the CJ-1H can accommodate either the HC-4O drifter or the HC-80.
The CJ-1H uses a centre-articulated Minejack carrier powered by a Deutz F6L-912W engine with a mine service rating of 61 kw. There are two operators seats on the CJ-1H. One for tramming and one for drilling. The CDJ-1H has only one operators seat. A BUC-35 boom with a 1.5-m feed extension is used on the CJ-1H and a BUC-24, with a 1-m feed extension is used on the CDJ-1H. Both booms maintain parallelism through the full coverage area. Boom movements are adjusted to provide smooth, positive control, says a company brochure. From the operating position, the operator can easily see the drill and feed, even while drilling lifters. Each boom can be positioned for drilling crosscuts or roofbolt holes.
The boom on either model is powered by an independent power pack. Three piston pumps and a 44.75-kw electric motor provide power on the CJ-1H and a smaller (37-kw) motor is used on the CDJ-1H. The motors are used for drill rotation, percussion circuits, boom movement and feed advance.
A travelling hose winder assembly maintains hydraulic hose tension. Standard hydraulic feed (ACT-5) is suitable for 4.3-m drill steel. At the end of the drilling cycle, the drill is returned automatically while water flushing and rotation continues. The operator only repositions the boom and applies full feed advance. Collaring and drilling are automatic. The HC-40 and HC-80 rock drills from Montabert feature a unique energy recuperation system, which greatly increases the life of bits, drill strings and drill components, the company says. The HC-40 delivers up to 325 joules of impact energy at a rate of 3,700 blows per minute and the HC-80 delivers 490 joules at 2,200 per minute. Circle reply card No. * Circle Reply Card No. b Eimco-Secoma
Eimco-Secoma specializes in small, compact drill jumbos. Since entering the international market three years ago, the company has made literally hundreds of 1-boom drill jumbos. Thirty or 40 have been sold in the U.S. alone. But so far only three have been sold in Canada.
(Tamrock's parent company is in the process of taking over Eimco- Secoma's parent company, Baker- Hughes. Before publication of next month's issue, it should be known whether the takeover is approved by U.S. regulatory officials, according to a spokesman for Eimco-Secoma.)
Eimco reports that its 1-boom jumbo is the most widely used in the world. The Helios 12 model (1.2 m wide) is the most compact unit available and has more power pound-for- pound of any 1-boom unit on the market today, the company says. The unit is equipped with Eimco's Hydrastar 200 hydraulic hammer, which is rated at 37 kw and weighs 110 kg. The hammer can deliver 150 joules of energy per blow at a rate of 40 to 66 blows per second. Holes measuring 27 to 41 mm in diameter are recommended.
The company also manufactures a slightly larger 1-boom unit called the Mercury 14. It is 1.4 m wide and comes equipped with a more powerful drifter (the Hydrostar 300). This drifter weighs 130 kg and is rated at 37 kw. The hammer can deliver 300 joules of energy per blow at a rate of 40 to 50 cycles per second. This size drifter is recommended for hole sizes ranging from 38 to 51 mm in diameter.
The Mercury 14 features an auto- parallel boom (called the B26) which the Helios model does not have. Power options include electric, diesel or diesel-electric. Circle Reply Card No. b MacLean Engineering/SIG
MacLean, based in Collingwood, Ont., is one of the latest companies to enter the Canadian market for single- boom, hydraulic, drill jumbos. But, as President Donald MacLean explains, the company doesn't fit the mold of a big jumbo manufacturer. Instead, it custom-builds jumbos for particular jobs at particular mines. MacLean has built 45 units that specialize in clearing hangups in boxholes, among other tasks. The company uses sig drifters, manufa ctured in Switzerland. Unfortunately, the company declined to provide further information on the design and sales volumes of their machines. Circle Reply Card No. b Tamrock Canada
Tamrock has not been sitting still in drill jumbo development. Later this year, a new single-boom jumbo should become available to Canadian mine operators, says Kaj Hulkkonen, product manager for Tamrock Canada in Sudbury, Ont. The new jumbo is called the Micro 103. It has been designed around Tamrock's new HE 300 drifter. The HE 300 has an output of 8 kw using 30-kw electric motors in the powerpack. It uses 1-inch integral drill steel or R25 or R87 drifter steels.
The Micro 103 jumbo is 1.2 m wide and can drill off a round in headings measuring 4.1 m wide and 3.3 m high. The 3.5-tonne unit comes equipped with a MR 300 automatic parallelism boom on a Tamrock 03 carrier. The turning radius of the unit is 1.4 m and the maximum tramming speed is 7 km per hour.
The company also markets two other 1-boom jumbos: the Monomatic HS 105C, which comes equipped with the HL 538 drifter, and the new Mono 106D. It comes equipped with the more powerful HL 500 (22-kw) super rock drill. This new generation of rock drills from Tamrock delivers 4,100 blows per minute, each with an impact energy of 325 Nm.
A new power control system incorporated into the Mono 106D jumbo automatically matches percussion power to the feed force. Combined with the higher power output, this feature serves to double the drilling capacity of the unit while saving on drill steel and bits, Hulkkonen says.
The 106D is 1.5 m wide and comes equipped with a ZRU 700 boom. Drift coverage is 5.5 m high and 7.3 m wide. Besides the new rock drill, the operator's cab has been totally re-designed as well. The operator of the new jumbo can run the unit from the seated position and can start the drill by simply flipping a lever. Other features include two-thirds fewer hydraulic hoses and electrical connections on the boom, a horizontal cable reel and enclosures for all hydraulics.
Tamrock's HL 538 drifter strikes with an energy of 250 Nm at a rate of 3,700 strikes per minute. Face coverage of the Monomatic HS 105 C is 4.76 m high and 6.1 m wide. Circle Reply Card No. b
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