Ronnie's Road Trip: Allis Chalmers charmer

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When he saw an old 1958 Allis Chalmers HD21 cable blade dozer rusting forlornly in a WA yard, Ron Horner couldn’t resist stopping to take a look

Allis -Chalmers -HD21-dozer
The blade was operated by cable and winch

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The beauty of semi-retirement is that you don’t! You never stop looking, comparing, sharing and caring for the industry which has given you so many good times and great memories, and provided you, and so many people you have come in contact with, with a good living and lifestyle.

I tend to travel a bit in search of anything vintage machinery and whilst on one of Ronnie’s Road Trips, I came across a bloody beauty.

Out in Western Australia’s mid-west, in a very small town and corralled up in a security compound, was one of the state’s original ‘Bush Tamers’. A classic example of old school elegance, muscle and beauty, it was none other than a 1958-model Allis Chalmers HD21 cable blade bulldozer.

The trip up along the coast was, as it always seems to be, a bit of a break from anything related to work. It never ends up that way – quite the opposite, really. Work rises to the top every time ... just like the ‘cream and milk’ thingy.

Verging on white-line fever after hours of looking at endless sand dunes and open flats, I slowed the old Hilux down as we entered the town. There were a couple of threatening signs to warn speeding drivers, a few old shops, a few old houses and then, out of the corner of my eye, I saw it.

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Ron points out the hand-operated lever to control the raising and lowering of the blade

Like that unforgiving 4am work alarm, I was jolted from my dulled senses when, through some mulga and a fence, I caught a fleeting glimpse of the old dozer sitting among a few other relics. But this was no relic; it was pioneering history in a paddock.

Past it already, I swung the Toyota back around and made tracks to the locked gate and the ‘Trespassers will be prosecuted’ sign. Peering through the fence, it was quite apparent that the old shed was locked and there were no vehicles within cooee. Bugger! No one around.

I walked the perimeter of the overgrown security fence line in hope of finding some clue as to who might be able to get me closer to the old Allis Chalmers HD21.

Over in one corner I found a sign which had a name and phone number on it; not the person who owned the shed by any means but at least a contact number which, hopefully, would give me a clue as to how I could get inside the yard.

The beauty of communication and the people of those great rural communities is that, if you ask nicely, almost anything is possible. This just happened to be the case on this day as I rang the number only to find that the guy was not home, working remotely and not due back for a couple of weeks.

I explained my position and, after four more phone calls later to others in the small community, I had contact. A guy would be down in about 30 minutes and give me access to view the old girl up close.

How good was that?!

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Those dash gauges were modern for the day

The history

This Allis Chalmers HD21 is rumoured to have been involved in clearing land in WA for more than 50 years, and no doubt would have been a pioneering spectacle when it arrived.

This old girl was driven onto the float from the property it had been clearing way out in the scrub. It had been working on and off for the last 30 years that anyone knew of. It had plenty more years in it but no blokes could be found to operate it.

The HD21 had been left in this holding yard for far too many years and was definitely showing big signs of neglect and theft. It needed a skilled surgeon, a portable defibrillator and the tender love and care of our Nurse Susie to get her operational again.

Way back in 1979, I ran an old cable-blade D8 which belonged to Sammy McMahon from Ben Bullen. Pilot motor start, two-speed gear shift and stop for forward and reverse – this old girl was not that different.

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Rear view of the cable drum winch

Leader of its day

The HD21 was designed to compete with the Cat D8 dozer and was a little cheaper in comparison.

Clearly ahead of its time, it led the way in dozers and ultimately forced Cat to change and modify its D8 range in an effort to keep up.

The HD21 was equipped with a new engine and superior track bearings that kept out the dirt, which Caterpillar finally adopted in 1958. The HD21 ended up becoming one of, if not the, best-seller in the Allis-Chalmers stable.

It weighed in at between 20 tonnes (1954 model) and 26 tonnes (1969 model) without any blade attachment.

Traditionally, machines competitive to Caterpillar have been a little cheaper and a little more powerful than the comparable Cat machine. When this earthmover was made in 1958, the comparable Cat was an early 46A D8, which featured a 235hp engine.

The reason why the Allis Chalmers HD21 is called a cable blade dozer is because its blade was operated by cable and winch. This lasted up until the 1960s, after which Allis-Chalmers incorporated a hydraulically operated blade.

After Allis Chalmers bought Buda, the company promptly converted the fleet over from Detroit diesel truck engines to the more powerful Buda diesel engines. The HD21 was one of the machines which featured an updated, Buda-designed engine.

The 6-cylinder supercharged engine produced between 204hp (1954 models) and 273hp (1963 model).

Allis -Chalmers -HD21-dozer
The Buda engine was rebadged to Allis Chalmers

One of the machine’s very best features was easy starting.

Compared to the Cats of the day, which still then often used a pilot motor to start the main engine, Allis Chalmers took the HD21 to the next level.

This engine started quickly even in cold weather with just a poke of the starter button. Indeed it was customary with this machine to spin the engine before turning the fuel on, just so it would start to pick up some oil before it started running.

While the engine was of a modern design, the bloody transmission was not and still featured a manual transmission installed behind a torque converter.

As per the designs of the day (and Cats were no different), the HD21 had a difficult-to-use manual transmission before the company started installing an all-PowerShift transmission in the ’60s.

To change direction, you throttled the engine down with a foot-controlled decelerator (like an accelerator except you step on it to idle down) and released the clutch with a long hand lever. You then slammed the gear shift in the other direction with a heavy lever about a metre long, set the clutch and released the throttle.

Calls for bigger engines developing more horsepower required major redesigns in strength and robustness … this could only equate to one thing, and that was extra weight. Back in the ’50s, this dozer weighed in at about 20 tonnes and the equivalent of today is about 36 tonnes.

The production of the HD21 pre-dated the OHS law that required a mandatory rollover protection canopy to be fitted to all dozers and other relevant earthmoving equipment.

However, many owner-operators and contractors added an aftermarket canopy, as was the case here.

The dash outlay is simple yet effective for what was required of the day. Simply put, there were only four gauges to distract the operator’s attention: oil pressure, water temperature, convertor temperature and ammeter gauges.

All were located to the right-hand side of the steering console in front of the operator.

Allis -Chalmers -HD21-dozer
This bloke isn’t having fun at all, is he?

Hats off

The seat was very large in comparison to others of the day, and as I eased myself into it I almost became a bit emotional thinking of the legacy this machine and its multiple operators have left on the harsh WA landscape over the many years of its working life.

Indeed, if you were an aspiring operator in the day, this is the one dozer you would be hoping to get your bum into.

This 1958 Allis Chalmers HD21 cable blade dozer deserves its place in our pioneering history pages … and in its final resting place in the WA mid-west.



Operating weight (without blade): 20 tonnes (1954); 26 tonnes (1969)

Engine: Buda-designed Allis-Chalmers 6-cylinder supercharged diesel

Power: 204hp (1954); 273hp (1963)

Length: 5020mm

Height: 2510mm


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