Image: Seen in a field on my travels around the North Island was this early 1960s model D with D scraper. Like some of the other D Tournapulls in this article, it has the supplementary air cleaner option fitted (with a missing connection pipe). It appears to have been recently repainted. Photo: Author’s collection
Richard Campbell reviews the model D Tournapull, which was descended from an earlier model D Tournapull before R.G. LeTourneau was sold to Westinghouse Air Brake Co. in 1953.
Introduced in 1946, the earlier model D Tournapull bore little resemblance to the widely successful model D that was to follow.
Marketed as a general-purpose, all-round scraper for small jobs, clean-ups, county roading, etc., the machine was offered with a range of optional attachments.
One of the machine’s big selling points was that, at only eight feet wide, it was legally roadable anywhere, enhancing its appeal. It also featured several innovations which would not be widely accepted until decades later.
Good old General Motors
The first new production model D Tournapulls could be powered by Cummins or Buda diesel engines. All subsequent production runs (both with Le Tourneau and Le Tourneau-Westinghouse) of the Model D Tournapull were powered by a naturally-aspirated four-cylinder General Motors Detroit Diesel 4-71 2-cycle diesel engine, which was rated at 138 horsepower in early machines, and as technology progressed, this rose to 148 horsepower.
The GM 4-71 was widely used by many heavy machinery manufacturers and enjoyed industry-wide acceptance.
Two transmissions were available for the Model D: direct drive and powershift.
Initial production models only offered a five-speed Fuller type 5A650 manual gearbox with a 14” single-plate clutch. However, from the mid-1960s, a 4-speed Allison CLT3341 powershift was also provided as an option, and this transmission later became standard.
By the time production of the machine was discontinued around 1973, the transmission had become a six-speed Allison VCLT3361 powershift with a variable input torque converter for more power during loading.
Never a particularly fast machine, the top speed was around 25mph with the powershift transmission.
How do we stop and steer?
The brakes on early Model D Tournapulls were of the air-operated, multiple-disc type, and very ahead of their time. However, poor maintenance practices and leaky seals often rendered them unusable, so around 1964, the change was made to more conventional air-operated expanding shoe brakes.
Steering was very unconventional for the time, consisting of a large ring gear bolted to the tractor unit’s kingpin with a pinion powered by an electric motor on the trailing unit; the two in constant mesh. The operator had fingertip control of the steering via a switch on the dashboard. However, engine revs were a critical part of this setup as a certain voltage level had to always be supplied to the steering motor for it to work; there was no steering wheel.
Many folks came unstuck by idling into a turn and then finding no steering!
As can be deduced, the heart (and most innovative) part of the machine was the electrical system, which consisted of a 300-volt AC generator attached directly to the diesel engine’s flywheel in front of the transmission. This provided, along with a transformer and oil bath rectifier, all the necessary electricity to operate the machine’s functions.
When properly maintained, this arrangement caused few problems but should routine maintenance lapse, or the operator become a little careless or complacent, then all sorts of excitement could ensue, ranging from slow bowl operation to the aforementioned complete lack of steering; a condition guaranteed to make a Christian out of the most die-hard atheist!
The operator was supplied with a comfortable bucket seat and enjoyed a reasonable view of the work area. All operating controls except the gearshift lever, brake pedal, throttle and clutch (on manual transmission models) were on the control panel in front of him. Initially, creature comforts were few; a fold-down windscreen, an uninsulated cab, and a heater were all optional extras that had to be specified when ordering a Model D.
Standard and optional equipment
When it was originally introduced in 1948, the standard scraper bowl supplied with the D Tournapull was the model E-9, which held six cubic yards struck and seven cubic yards heaped. In 1952, this was replaced by the redesigned model D scraper, which held 7.3 cubic yards struck and 9 cubic yards heaped. Both scrapers were of conventional design, and all functions – bowl, apron, and ejector – were controlled by separate, identical electric motors and winches acting on short lengths of cable.
The model D had an easy loading bowl and could self-load most materials, including sand.
The contractor had a range of attachments available to convert the Model D into something other than a scraper, including a crane (Tournacrane), rear dump (Tournarocker), flatbed logging trailer, skidder arch, and nose-mounted bulldozer.
Another very popular option was an 11-cubic-yard elevating scraper manufactured by Hancock known as the model 10E2. As this transformed the machine completely (even Le Tourneau-Westinghouse gave it a different designation, the model 111A), this machine will be the subject of an upcoming article.
Switching attachments was, in general, very easy and, in most cases, a morning’s work for the average technician. All that had to be done was disconnect the main electrical loom and undo four bolts to convert to all but the elevating scraper.
The usual tyre equipment for a model D Tournapull was a matched set of 18.00×25 E3S, with later machines having the option of 23.5×25 E3S.
A long and productive career
During its long life, the Le Tourneau-Westinghouse Model D was manufactured in three countries: the USA, Australia, and Brazil. Many thousands were produced (the exact number is unknown), and over 30 were imported into New Zealand, most of these coming from the Australian manufacturing plant at Rydalmere.
Over the years, various cosmetic changes were made to the machine, mainly to the radiator surround (as seen from the attached images).
During 1970, the machine received a change of model name to the type 109A (to bring it into line with other Wabco scrapers of the period). Still, the writing was on the wall – the demand for seven-yard, open bowl scrapers had all but dried up, with most contractors opting for elevating scrapers instead. The decision was made to terminate model D/109A scraper production in 1972.
At this point, the little machine outlasted all its competitors over the years, and examples can still be found operating.
For the model collector
Regrettably, for such a popular machine, no models have been issued of the little model D Tournapull in any scale.
This is somewhat of a travesty considering the amount manufactured, and the time the machine was in continuous production (24 years).
It is hoped that some enterprising model manufacturers will address this oversight in the near future.
Parting words from Jeremy Sole- a final column