Cover Story: ASV RT-120 Posi-Track Forestry com­pact track loader with Fe­con Bull Hog mulcher

It takes to lot to turn heads in the veg­e­ta­tion man­age­ment game, but ASV’s RT-120 Forestry Posi-Track loader and Fe­con’s Bull Hog mulcher have a head-start, says Barry Ashen­hurst

Earthmovers & Excavators - - Contents -

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Skid-steer or com­pact track load­ers are pop­u­lar mulching de­vices be­cause they’re ag­ile com­pared with mulching trac­tors do­ing the same job. A com­pact loader will get in and out of tight spa­ces while a full-size trac­tor can only scoff dough­nuts and watch.

Al­though not the most ef­fi­cient com­bi­na­tion for tack­ling large stem sizes, the lat­est ASV RT-120 Forestry Posi-Track, fit­ted with Fe­con’s up­graded Bull Hog mulcher, will push over trees up to 203mm (eight inches) in di­am­e­ter, and is pos­si­bly Aus­tralia’s only com­pact loader with such a fo­cused ob­jec­tive.

It has to be said, though, that ap­pli­ca­tion still rules. There’s no such thing as ‘the best com­pact loader on the mar­ket’. Each one has its good and bad fea­tures.

Wheeled load­ers are bet­ter for some ap­pli­ca­tions, but there’s been a swing from wheeled to tracked load­ers over the past few years, largely be­cause of their su­pe­rior sta­bil­ity and lower ground pres­sures – the lat­ter an ad­van­tage when work­ing sen­si­tive ground with­out cre­at­ing the dam­age that a wheeled loader might.

One com­pany which made a big name for it­self with low-ground-pres­sure earth­mov­ing tools is ASV (All Sea­sons Ve­hi­cles), a com­pany started by for­mer Amer­i­can snow­mo­bile ex­ec­u­tives Edgar Het­teen and Gary Lemke.

In 1945 Lemke founded Po­laris In­dus­tries, which be­came an em­pire, and in 1961 he founded Arc­tic Cat, which didn’t.

Then in 1983 he and Het­teen es­tab­lished ASV with a ve­hi­cle that com­bined the most use­ful at­tributes of a snow­mo­bile and a trac­tor. They called it the ASV Track Truck.

Its steer­ing sys­tem al­lowed the op­er­a­tor to in­di­vid­u­ally con­trol dual rub­ber tracks. The front end could be fit­ted with ei­ther wheels or skis, and it turned out that this hy­brid was very good at ma­noeu­vring through the boggy, swampy ter­rain so char­ac­ter­is­tic of the Min­nesota re­gion.

His­tory is writ­ten by win­ners and I won’t strain your pa­tience by de­scrib­ing what hap­pened af­ter that. Enough to say that ASV pro­duced the PosiTrack rub­ber-tracked loader in 1991, now lives in Grand Rapids, Min­nesota, has a work­force of more than 100, and has cor­nered a healthy share of the Amer­i­can and Aus­tralian com­pact tracked loader (CTL) mar­ket.

ON THE JOB

Veg­e­ta­tion man­age­ment is an ideal ap­pli­ca­tion to test the abil­i­ties of a tracked loader, the rea­son we hooked up for a demo this month with ASV

We did a lot of field work to make sure the RT-120 would con­tinue to op­er­ate ef­fi­ciently in tough Aus­tralian con­di­tions. That was very im­por­tant

Sales & Ser­vice mar­ket­ing man­ager Chris Wolf. ASV Sales & Ser­vice is the Aus­tralian im­porter and dis­trib­u­tor for Posi-Track com­pact load­ers and Fe­con’s range of hy­draulic mulchers.

We spent a day watch­ing the com­bi­na­tion work a ru­ral plot in the New South Wales Hunter Val­ley, push­ing over small trees then mulching their re­mains. It was im­pres­sive, but the ob­ject of the ex­er­cise was to find out how ASV im­proved the lat­est model – so let’s have a look at that.

The RT-120 re­places the Terex PT-110 and it seems that ev­ery­thing but the fa­mous un­der­car­riage has been tweaked.

The power plant is now a 3.8-litre Cum­mins rather than a 3.4-litre Perkins. The new en­gine is Tier 4 com­pli­ant, which means it meets US emis­sion stan­dards. The Perkins was Tier 4 com­pli­ant too but the Cum­mins has 120hp (com­pared with 111hp) and 488Nm of torque (com­pared with 450Nm). It’s not a big dif­fer­ence but, as the ex­perts say, you need all the power you can get when you’re mulching.

The chas­sis is new as well. So is the cab, which now has air-con­di­tion­ing that copes more eas­ily with sticky Aus­tralian sum­mers – no small mat­ter when you’re sit­ting in a con­fined space that with­out de­cent seal­ing would be lit­tle more than a sauna with win­dows.

Since mulching in­vari­ably gen­er­ates a cloud of air­borne de­bris, the cabin is pres­surised so that fine ma­te­ri­als can’t en­ter your airspace. The en­gine fan is re­versible so woody ma­te­rial that gets past the ra­di­a­tor can be forcibly ejected.

The stan­dard cab has brush sweeps over the bon­net, and guards for the front and rear lights and air-con­di­tion­ing con­densers.

In short, Wolf as­sures me, the Posi-Track is pro­tected from the sort of ac­ci­den­tal dam­age that of­ten oc­curs in ex­treme en­vi­ron­ments where ‘stuff can fall on you’. Gen­eral ser­vice­abil­ity is im­proved too, es­pe­cially to the hy­draulic cool­ing equip­ment.

TOUGH HY­DRAULICS

Run­ning a high-per­for­mance hy­dro-me­chan­i­cal de­vice like a mulcher re­quires equally high per­for­mance from the loader’s hy­draulic sys­tem, a char­ac­ter­is­tic of the RT-120 that Wolf be­lieves makes it a per­fect fit for the ap­pli­ca­tion.

“On top of that,” he says, “the hy­draulic sys­tem is op­ti­mised in that the loader is putting out 170 lpm while run­ning at 4060psi (27,993 kPa).

“With the com­bi­na­tion of high en­gine horse­power, high flow and high pres­sure, we think we have the most pow­er­ful com­pact loader on the mar­ket, de­signed for this type of work.”

Wolf says that, when you’re putting out so much oil at such high speeds, it’s im­por­tant to keep hy­draulic tem­per­a­tures un­der con­trol.

“With that in mind, I think ASV has done a good job of en­gi­neer­ing the cool­ing pack­age to suit the ap­pli­ca­tion and the Aus­tralian cli­mate,” he says. “We did a lot of field work to make sure the RT-120 would op­er­ate ef­fi­ciently in Aus­tralia. That was very im­por­tant.”

But the loader is only half the pack­age. Al­though the Phase 3, Fe­con Bull Hog mulcher still car­ries the pre­vi­ous mulcher’s BH85SS des­ig­na­tion, it too has been up­graded.

It has the largest drum in its class, and stag­gered, spi­ral-pat­tern dou­ble-car­bide teeth that can process Aus­tralia’s leg­endary hard­woods. The mulching cham­ber it­self has been stream­lined to smooth the pas­sage of pro­cessed tim­ber.

As you’d ex­pect, says Wolf, mulching soft pine takes less horse­power than chew­ing up hard­wood but with 120hp be­hind it, high-ca­pac­ity hy­draulics and dou­ble-car­bide teeth, the Bull Hog is ready to chew ’em all down to mulch.

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1. Come to mama. Small stuff doesn’t stand a chance when it reaches the mulcher’s maw. The Fe­con is rated to han­dle stem di­am­e­ters up to eight inches (203mm)

2. Two in­de­pen­dent tor­sion axles sus­pend each of the ASV’s track frames, plus four in­de­pen­dent wheel car­riages (4 wheels each) per track

3. The Fe­con Bull Hog mulcher has dou­ble-car­bide teeth set in a stag­gered pat­tern so that only one tooth at a time is ac­tu­ally in con­tact with the tim­ber. ASV says this setup will han­dle hard­woods as well as soft­woods 3

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