There is an inherent fascination with large pieces of earthmoving equipment, no matter what function they perform and the rarer those pieces of equipment are, the more mystique that builds up around them and their capabilities. This is certainly the case with the Allis-Chalmers 562, the largest motor scraper that Allis-Chalmers ever built. By Richard Campbell
Based around a modular concept which allowed for the addition of an extra scraper bowl if necessary, the Allis-Chalmers 562 was developed from the existing model TS-460 single engined, open bowl scraper with which the tractor unit of the 562 shared many major components.
It was Allis-Chalmers’ first attempt at a twin powered machine and the company had great hopes for the 562 and its ability to make inroads into the large capacity twin scraper market, at the time dominated by Caterpillar’s 657 & Euclid’s TS-32.
With a 30 cubic yard bowl, and 730 horsepower at its disposal, the 562 certainly looked good on paper.
First deliveries of the new machine commenced in 1962 and initial reports were very favourable citing plenty of power and speed. Operator opinions were also very good regarding the machines handling characteristics, riding qualities and visibility compared to other makes.
Then the gremlins began to appear.
These took the form of detonating engines, tyre failures due to exceeding ton/mph ratings and the bugbear of all large machines: structural failure.
It wasn’t that the 562 was a bad machine, just that technology had not quite kept pace with it and Allis-Chalmers’ enthusiasm to get the machine into production had led to insufficient testing of the prototypes.
Allis-Chalmers more or less cured the engine problems by replacing the original fitted model Allis-Chalmers 21000 engines and installing derated model 25000 engines in an attempt to get more engine reliability, at the same time renaming the machine the 562B.
The structural failures were kept in check by adding more steel in the problem areas.
However, this in turn caused another problem as now the machine was heavier but had less power to haul itself around, making it not much better than the machines it was meant to compete with.
Compounding this problem were the now even more overloaded tyres.
It has to be mentioned at this point that Allis-Chalmers was not alone in having tyre problems caused by heat buildup and overloading. This affected many scraper manufacturers during the 60s and 70s as rubber companies scurried to keep pace with the development of high speed earthmovers.
Citing low machine sales, the Allis-Chalmers 562 was discontinued from production in 1966 after approx 150 units had been delivered. I do not know whether any still survive.
As part of its modular concept, Allis-Chalmers had also put into production a specialized twin-powered rubber-tyred articulated-steer push tractor, manufactured out of two 562 tractor units joined by a special hitch, called the model 555. This was designed solely as a high speed scraper pusher for large jobs but, beset by mechanical problems, fewer than 10 were actually sold.
The model 555 disappeared from the Allis-Chalmers sales catalogue before 1965.
The Allis-Chalmers 562B described.
A large twin engined motor scraper, the 562 was powered with two identical Allis-Chalmers model 25000 turbocharged diesel engines rated at 365 horsepower each.
Matching Twin-Disc five-speed powershift transmissions and Allis-Chalmers Kon-Tork power transfer differentials and double reduction bull gear and pinion final drives completed the power train.
Capable of a top speed of almost 32 mph, the 562 was usually shod with 33.5 x 33 tyres.
Stopping such a large beast was entrusted to identical air actuated shoe brakes on all four wheels and a hydraulic retarder fitted to the front transmission.
Allis-Chalmers used the same two-cylinder hydraulic steering system as fitted to its smaller scrapers. This allowed full 90 degree turns to either side of centre.
The business end of the machine held 30 cubic yards struck and 40 cubic yards heaped and was all hydraulic in operation with a four-section reversible cutting edge fitted.
Bowl raising and lowering was done by two double acting hydraulic cylinders mounted unusually splayed at a 30 degree angle, which allowed cutting edge down pressure when loading. Apron actuation mimicked Euclid’s with a single stage ram acting on a lever and short length of cable to raise the apron.
Ejection was of the roll out type, also similar to Euclid, the 562 being the only Allis-Chalmers scraper to use this manner of ejection.
Operator efficiency was given a great deal of thought by Allis-Chalmers and the operator’s compartment was roomy and well laid out with an air suspension seat, full instrumentation and all operating controls placed close to hand.
A nice touch was the standard addition of a wide rear view mirror across the top of the machine’s windscreen, which allowed the operator to view the loading cycle without having to constantly turn his head and body around. This feature was subsequently added to all Allis-Chalmers motor scrapers
The New Zealand connection
No Allis-Chalmers 562s were imported into New Zealand, either new or second hand.
Considered too large for New Zealand jobs (as was the slightly smaller TS460), local contractors preferred the versatility and flexibility of smaller sized scrapers.
In hindsight, something as large as an Allis-Chalmers 562 would have been ideal on the many and varied opencast coal extraction jobs in the Waikato, however, no one at the time was willing to take the risk.
Feast Contractors were to prove this mindset was a fallacy in the mid 70s when they imported five 32 cubic yard Euclid TS-32s from the USA.
For the model collector
You are in luck if you have deep pockets as there is a very nice 1:50th scale Allis-Chalmers 562 available as a limited run item from EMD Models.
Cast in resin and white metal, this is quite an imposing model and has a lot of detail on it but will set you back in excess of NZ$600 apiece and is only available from a couple of outlets within the USA.
Not a purchase for the faint hearted!
Brief specifications – Allis-Chalmers 562B
Engines: 2 x Allis-Chalmers model 25000, 6-cylinder, turbocharged diesel engines rated at 365 flywheel horsepower each
Transmissions: 2 x Twin-Disc 5-speed full powershift transmissions with integral hydraulic retarder on front transmission
Final Drives: Double reduction bull gear & pinion
Differentials: Allis-Chalmers ‘Kon-Tork’ torque proportioning
Top Speed: 31.7 mph
Brakes: Full air operated expanding shoe type.
Steering: Hydraulic, double acting cylinders, 90° each side
Turning Circle: 31’ 3”
Std.Tyres: 33.5 x 33, 32-ply (tractor), 33.5 x 33, 38-ply (scraper)
Capacity: 30 cubic yards struck, 40 cubic yards heaped
Operation: Full hydraulic with hydraulically actuated cable apron.
Length: 47’ 11”
Height: 15’ 7”
Operating Weight: 51 tons (empty), 101 tons (loaded) approx.