LeTourneau was first of the blocks with a wheeled bulldozer, a roadable and manoeuvrable machine suited to many earthmoving jobs. Here we take a closer look at the LW12 Tournatractor. By Richard Campbell
As earthmoving methods developed and newer and faster machines were introduced, it became apparent to RG LeTourneau that the track type tractors of the day weren’t keeping up and the need for a higher speed tractor to cope with the increased pace was necessary.
The end result the Tournatractor, which was basically a rubber tyred bulldozer that could move quickly around the jobsite and even over the road if necessary.
LeTourneau was the first manufacturer to come up with this idea, followed by LaPlant-Choate in 1946 and Caterpillar, Hough and Michigan in the early 1960s.
This month we’ll look at LeTourneau’s LW12 wheeled bulldozer, which had its origins much closer to New Zealand.
LeTourneau had several production facilities both in the USA and overseas, and one of the more dynamic and inventive was the factory at Rydalmere in New South Wales, Australia.
Seeing a market opportunity for a smaller wheel type bulldozer they began design of what was to become the Model LW12 in 1959 with prototype testing also begun in the same year.
Initially the machine had its engine in front of the operator like a conventional tractor, but as field testing progressed a rear engined layout was trialled and found to offer many benefits. The majority of LW12s were constructed in this configuration.
At 14,600 lbs weight (7 tons) the LW12 was an ideal size for all the medium to smaller jobs that would normally have required a track type tractor, with the added benefit that the machine didn’t need to be transported and could drive itself to the job site.
Local authorities embraced this concept as the machine could work a number of jobs and then drive off to work elsewhere – legally.
Smaller contractors loved the versatility that the machine offered them, particularly on subdivision work where the machine could travel all over the jobsite quickly and perform a number of tasks, from push loading scrapers to fill trimming and pulling a compactor.
The only two downsides to the machine were those which affect all rubber tyred equipment – rain and rocks
While the LW12 was an extremely versatile machine, slipping and sliding around on wet clay in a Tournatractor wasn’t much fun and, in the hands of a careless operator, rocks could destroy tyres very quickly. In this respect the track type tractor had a distinct advantage.
LeTourneau-Westinghouse Australia built approximately 60 LW12 Tournatractors before the type was discontinued in 1964.
LeTourneau-Westinghouse also manufactured a larger version of the LW12, the LW16. This enjoyed a much more successful production run with well over 200 being produced, many for export.
It was built in two distinct versions – one with the engine up front (LW16T) and the other with the engine in the rear (LW16R). Both were usually powered by a GM 6-71 diesel.
The LW12 Tournatractor described
General Motors supplied the engine for the LW12, a Detroit Diesel model 3-71 three-cylinder inline two cycle diesel rated at 108 flywheel horsepower.
Buyers also had the option of a Ford six-cylinder diesel rated at 96 horsepower but very few of this variant were built and, as far as I can tell, none came to New Zealand.
The transmission was a LeTourneau direct drive sliding gear type with five forward and one reverse gear. In fifth gear, the LW12 could cruise along the road at 20 mph.
Final drives were very similar to a motor grader, being chain driven off a central bull gear.
Steering was via steering clutches similar to a track type tractor.
Due to the drivetrain configuration and extremely short wheelbase, the LW12 could practically turn 180 degrees in its own length, making it highly manoeuverable.
Air operated expanding shoe type brakes were employed on the rear axle only plus a mechanical contracting brake acting on the transmission output shaft, which was used for parking.
Tyres of choice were usually 14.00 x 24 12 ply but other sizes could be specified if the buyer requested them.
The entire chassis assembly was constructed around a central ‘tub’ which held all the essential parts in alignment and provided a great deal of protection for the underside of the machine.
As for the operator, he had a great view of the blade and to either side of the machine. Visibility to the rear was of course somewhat limited due to the location of the engine, aircleaner and exhaust. All the operating controls were well placed and easy to use.
Access to the driver’s seat was not all that easy due to the configuration of the drive wheels, the easiest method being to mount the machine from the rear of one of the final drive housings.
A cab wasn’t offered but a canopy was available as an option to keep the sun and rain off. Other optional extra were limited to various lights, and a PTO.
Having operated one of these machines, I found it quite delightful to drive with a great view of the work area.
The only minor drawback was in dozing into the wind where any blade overspill over the top of the blade had a bad habit of ending up in your face. When working in sandy soil this was not too pleasant!
Standard blade for the LW12 was an eight foot wide straight bulldozer, which could be tilted for ditching, shaping, etc. The majority of LW12’s had this type of blade fitted.
The operator did not have to leave the seat to change the tilt angle, a precursor to today’s popular PAT blades perhaps?
Other tools included an hydraulic angle blade and a three-shank hydraulically operated ripper.
A New Zealand connection
At least four and perhaps as many as six LW12 Tournatractors were imported into New Zealand by Dominion Motors, Earlo Tractor Co and latterly Fredric W Smith Ltd, the LeTourneau-Westinghouse distributors of the day
Although delivery records are sketchy at best, they all appear to have been delivered to North Island customers
To the best of your writer’s knowledge, the only surviving example(s) belong to Goodman Earthmovers of Waikanae
For the modeller
As might be expected with a rare beast such as the LW12, no models exist in any scale.
Brief specifications – LeTourneau-Westinghouse LW12
(Dimensions given with standard S blade and ripper)
Engine: GM model 3-71, 3-cylinder, inline, naturally aspirated diesel rated at 108 flywheel horsepower at 2300 rpm
Transmission: LeTourneau direct drive manually shifted 5-speed sliding gear transmission
Clutch: Rockford 16’’ single plate
Top Speed: 20 mph
Steering: Air operated multiple steering clutches
Brakes: Air operated expanding shoe type. Rear axle only
Tyres (std): 14.00 x 24, 12 ply
Turning circle: Due to the set up and short wheelbase, an LW12 could make a 180° turn in practically its own length
Length: 16’ 4’’
Height: 6’ 5’’
Operating Weight: 7 tons