November_1970 — Page 48

contractors

plant

COMPRESSOR

A compact design and a good power-to-weight ratio are features of the new DR 25000 compressor which delivers 250 c.f.m. of free air at a working pressure of 100 psi.

Power for the oil-sealed rotary machine in supplied by a Perkins 6.354 six-cylinder diesel engine de- veloping 77 h.p. (continuous rating) at its 1800 r.p.m. full-load speed. An

DR 25000 compressor

automatic control reduces off-load running speed to 1250 r.p.m.. Other standard fittings include a built-in air- intake filter, oil filter, safety valve, oil separator and automatic unloader pres- sure control.

The direct-coupled engine and and compressor form a single rigid unit mounted on a steel tubular chassis which has independent torsion-bar suspension with two 6.00-16 six-ply tyres, a towing eye and over-run brakes. The unit's housing comprises a detachable steel cover with side panels and g.r.p. ends which incorporate steel reinforcement and detachable grilles.

The makers are Ing. Enea Mattei, s.p.a., Milan. Agents in Thailand are United Machinery Co. Ltd., Bangkok.

ELEVATING SCRAPER

The first four-wheel drive scraper to be introduced by Clark Construc- tion Machinery, Benton Harbor, Mich., USA, is a 16 cu. yd. elevating scraper designed for work on steep gradients and soft ground.

Called the Michigan 110H-T, it fea- tures both front and rear-drive engines (160 h.p. GM Detroit diesels). Its 61⁄2 ft. wide, hydraulically driven elevator flights load a variety of soilds in less

than a minute.

The 110H-T has a power-shift transmission with five forward speeds and two reverse speeds. Top speed is 29.5 m.p.h. A single-phase torque con- verter and heavy-duty axle with plane- tary reduction in each wheel complete the power train. Rated load capacity of the machine si 38,400 lb.

The 9 ft. 11⁄2 in. wide scraper bowl has a rigid mold-board and a one-piece reversible cutting edge and four ripper teeth that dig material easily.

The fixed cutting edge permits longer hydraulic component life be- cause it does not depend upon hydrau- lics for its operation. Constant depth lifts across the full width of the bowl are obtained through a strike-off blade feature. The height of the elevator

above the cutting edge may be chang

ed through a three-position adjustable block to give easy loading of a variety of materials.

CRAWLER TRACTOR

After seven years of research and development, Allis-Chalmers, Milwau- kee, Wis., USA, have produced what is claimed to be the world's largest craw- ler tractor, the HD41.

Working as a dozer equipped with a U-blade, the machine can doze up to 24 loose cu. yd. per pass on a 0% grade and to 38 loose cu. yd. per pass on a 25% downgrade.

The power unit is a 524 net flywheel h.p., 1710 cu. in. displace- ment V-12 overhead valve engine. This is coupled to a single-stage rotating housing torque converter with a multi- plication factor of 2.88:1. Drive train on the HD41 consists of a three- speed, power shift, constant mesh, counter shaft transmission with input clutch that operates automatically for on-the-move shifting.

Top forward speed is 6.5 m.p.h. and top reverse speed 7.4 m.p.h. All controls are fully powered and steering clutches and brakes are hydraulically actuated.

Track gauge is 100 in. with ap- proximately 9200 sq. in. of track on the ground. Weight is evenly distribut- ed with a low centre of gravity permit- ting the machine to operate with only 11 p.si. ground pressure with standard shoes.

Overall width is 11 ft. 11⁄2 in., length 20 ft. 2 in. and height 10 ft. 4

in.

TAMPER

Asphalt, sand, gravel and most non- cohesive soils can be compacted with the Model T-401A vibrating pan tam- per which produces 1800 lb. of impact at 4800 vibrations per minute.

Michigan 110H-T scraper

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524 h.p.HD-41 tractor next to a 59 h.p. Model 652

Far East BUILDER, November 1970