LeTourneau’s Model D Tournapull

The Le Tourneau-Westinghouse D Tournapull was one innovative machine, says Richard Campbell.

Descended from the original Le Tourneau ‘D’ Pull which dated back to 1946 and before the sale of the company to Westinghouse in 1953, the Model D was marketed as a general purpose all-round scraper for small jobs, clean ups, county roading etc., and was offered with a range of optional attachments. The machine was also legally roadable anywhere, enhancing its appeal.

A very simple in design, the Model D actually featured a number of innovations which would not be widely accepted until decades later.

Throughout its entire 25 year production life (both with Le Tourneau and Le Tourneau-Westinghouse) the Model D was powered by a naturally aspirated 4-cylinder General Motors Detroit Diesel 4-71 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 wide acceptance.

A choice of two transmissions were available for the Model D – direct dive and powershift.

Initially only a 5-speed manual Fuller type 5A650 with a 14” single plate clutch was available but, from the mid 1960s, a 4-speed Allison CLT3341 powershift was offered as an option and this later became standard.

By the time the machine was discontinued the transmission had become a 6-speed Allison VCLT3361 powershift with variable input torque converter for more power during loading.

Top speed was 25mph with the powershift transmission.

The brakes on early Model D Tournapulls were of the air-operated multiple-disc type and very ahead of their time. However, poor maintenance and leaky seals often rendered them unusable and the change was made to more conventional expanding shoe brakes around 1964.

Steering was also unconventional consisting of a large ring gear bolted to the tractors unit’s king pin 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 dash panel. There was no steering wheel!

The most innovative feature, and the heart of the machine was the electrical system.

This consisted of a 300v 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. However should routine maintenance lapse or the operator become a little careless or complacent then all sorts of excitement could ensue. This ranged from slow operation of the bowl to complete lack of steering at speed – a condition guaranteed to make a Christian out of the most die hard atheist !

Standard equipment for the Model D was a 7.3 cubic yard struck, nine cubic yard heaped open bowl scraper of conventional design.

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 in most material, including sand.

The operator was supplied with a comfortable seat and enjoyed a reasonable view of the work area. All operating controls except the gearshift lever were on the control panel in front of him.

A windscreen or cab and a heater were all optional extras that could be specified when ordering a Model D.

As mentioned earlier, a range of attachments were available to convert the Model D into things other than an open bowl scraper.

These included a crane, flatbed logging trailer, skidder arch, bulldozer and rear dump, the latter of which was very popular in New Zealand.

The other attachment was the elevating scraper.

As this transformed the machine completely (even Le Tourneau-Westinghouse gave it a different designation), this will be the subject of an upcoming article.

Switching attachments was, in the main, very easy and a morning’s work in most cases. 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 Le Tourneau-Westinghouse Model D was in continuous production right through until 1971 when the demand for seven yard open bowl scrapers had all but dried up, the majority of contractors preferring the elevating scraper instead.

It outlasted all of its competitors. In the last two years of production the machine was known as the Model 109A.

The machine was manufactured in the USA, Australia and Brazil and many thousands were built.

The New Zealand connection

Over 25 Model D Tournapulls were imported into New Zealand over its production span by three NZ distributors: Earlo Tractor Company, Fredric W Smith Ltd and Domtrac.

Many of the rural roads in Northland and the Wairarapa plus significant stretches of State Highway 27 were created using Model D Tournapulls.

Users included K.J.McMillan Ltd, W.Kehoe Ltd, Ramsay & Son, White Contracting and of course, the premier Le Tourneau operator Goodman Earthmovers.

The majority of the machines imported were of Australian origin but there were a few US built examples as well.

The author has operated most types of Model D and remembers them fondly.

In fact he would like to obtain one for restoration!

Brief Specifications – LeT-W Model D

(specifications are for the most common NZ examples)

Engine:                        General Motors 4-71, 4-cylinder naturally aspirated, inline diesel, 143 horsepower.

Transmission:             Fuller 5A650 5-speed step gear transmission. 1 reverse gear.

Clutch:                          Rockford 14” single plate.

Brakes:                        Multiple-disc, air-operated on all four wheels.

Std.Tyre:                     18.00×25.

Top Speed:                 29.2 mph.

Steering:                      Positive electric kingpin steering.

Capacity:                    7.3 yd³ struck, 9 yd³ heaped.

Operation:                   Independent electric motor control of all functions.

Length:                        28’1”.

Width:                         8’.

Height:                         9’1”.

Operating Weight:       10.2 tons (empty), 20 tons (loaded).


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