The LeTourneau Model C and Super C Tournapull

Perhaps no other motor scraper in the history of the genre helped to change the way that contractors thought about moving earth than the LeTourneau C Tournapull.   BY RICHARD CAMPBELL

C_Pull_1.jpgLegend has it that the idea of the Tournapull motor scraper came to RG LeTourneau while he was in hospital recuperating from a serious car accident.

Since the early 1930s LeTourneau, had been one of Caterpillar’s largest suppliers of bulldozer blades, towed scrapers, cable controls rippers and a host of other ancillary equipment. RG LeTourneau approached Caterpillar management with his idea of a motorized scraper but was told the idea was not feasible. Undaunted, he began manufacture of the machines in his own facilities, and it was not long after this that LeTourneau and Caterpillar went their separate ways.

The Model C Tournapull was the second of RG LeTourneau’s Tournapull range to appear (the first was the Model A).

C_Pull_2.jpgHis newly built factory in Peoria, Illinois produced the first Model C in April 1940. It looked quite unlike anything that had been seen before and, despite an initial hesitance on the part of the conservative contracting industry, this machine could shift dirt faster over longer distances than anything that was previously available, and certainly at considerably less cost than a track type tractor and scraper rig.

These first Model Cs were powered with a Caterpillar model D468, four-cylinder diesel rated at 90 horsepower with a four-speed manual Fuller truck transmission.

The standard scraper was a LeTourneau type ‘LS’ rated at 8.2 cubic yards struck and 11 cubic yards heaped.

As the machines acceptance began to grow, the need for more carrying capacity became obvious. It was at this point that the most famous of all the Tournapulls, the ‘Super C’ came into being.

Outwardly the Super C Tournapull resembled the existing Model C but in fact it was quite a different beast. Officially introduced in 1941, the Super C had a choice of four diesel engines that could be fitted depending on customer preference – 150 horsepower Buda 6DH-691, 140 horsepower Hercules DRXC, 150 horsepower Cummins HBID-600 or 152 horsepower General Motors 6-71.

Although the Model LS scraper could be used with the Super C Tournapull tractor unit, the most common scraper used by far was the 15 cubic yard heaped type ‘LP’.

The Super C Tournapull sold in the thousands, both to military contracts and to private contractors. It was a classic case of the right machine at the right time. C and Super C Tournapulls saw service worldwide and the type was manufactured through until 1949 when it was replaced by more modern machines.

The C Tournapull described

C_Pull_3.jpgAs the most widely produced version of this famous machine was the Cummins-engined Super C, this is the type we will examine in detail.

The Cummins HBID-600 six-cylinder diesel produced 150 flywheel horsepower at 1800 rpm and was connected to the Fuller 4A1120 manual transmission by a 16 inch dry plate clutch.

A bull gear and pinion final drive was employed with all herringbone pattern gears in the drive train. This was most unusual and produced a final drive of considerable strength.

Steering was accomplished just like a track type tractor – with steering clutches and contracting band brakes. This led to the rather unfortunate nickname of “widow maker” being bestowed on the machine, as it could catch the novice operator out, usually with disastrous consequences.

Pneumatic tyres for earthmoving were in their infancy when the C was introduced and many sizes and configurations were trialled.

On the Super C usual tyre equipment was 21.00x24 on the tractor and either two 21.00x24 or four 18.00x24 on the scraper.

The top speed of the unit was around 15 miles per hour.

C_Pull_4.jpgOn the back of the tractor units’ main case was the double drum cable control unit (usually a LeTourneau model T) which operated all the scraper functions. The scraper was attached to the tractor unit by a C-type yoke fastened at the top by a ball joint and at the bottom by a drawbar.

Failure of either of these components usually ended in a trip to the hospital (or worse) for the operator – if the top joint failed the machine would nose into the dirt, followed closely by the operator, if the lower joint gave way the machine’s nose would point to the sky and the operator would be buried in the bowl’s contents. It was all exciting stuff and not for the faint hearted.

Probably the most famous of all of LeTourneau’s towed scrapers, the type ‘LP’, was adapted for use behind the Super C Tournapull and in this configuration was known as the Model ‘LP-C’.

All cable controlled, the LP-C was rated at 12.1 cubic yards struck and 15 cubic yards heaped.

Featuring a three-section cutting edge, the LP-C was exceptionally rugged in design and construction – in other words a typical LeTourneau product.

A small triangular braced push block, with either a fixed or swivelling push plate, was attached to the rear of the scraper to allow boost loading by a track type tractor.

C_Pull_5.jpgThe machine could also be load assisted by what was known as “snatch loading” whereby a track type tractor equipped with a long cable operated pole would pull load the Tournapull via the tow hook on the Tournapull’s crankcase guard. Photos of machines loading in this fashion are quite rare as it took a very accomplished operator to perform this task smoothly.

 

The New Zealand connection

It is not known how many C & Super C Tournapulls were imported into New Zealand. The franchise holder at the time, Earlo Tractors, has long since ceased trading and other records are sketchy at best.

What is known is that almost all of the machines were manufactured in Australia at LeTourneau’s plant in Rydalmere, NSW. LeTourneau had set this facility up just before WWII and had also designed its own version of the C Tournapull, which was sometimes equipped with a type ‘MS’ scraper. ‘MS’ scrapers were very similar in size and capacity to the USA-built type ‘LS’.

The favoured powerplant in Australia was the GM ‘71’ series diesel engine, consequently, most of New Zealand’s Tournapulls had a GM engine installed.

A great many New Zealand contractors owned Tournapulls at one time or another and at least three still exist in collections – Higgins Earthmoving in the South Island owns a Standard C Tournapull, and the collection of the late Graeme Craw has a Standard C and a Super C with an LP scraper which was imported from the USA about 4 years ago.

For the modeller

C_Pull_6.jpgFor once the modeller is well catered for as there are at least three variations of the Super C Tournapull available with another due for release later in 2010.

All of these models are to 1:50th scale.

Spec Cast offer a Cummins powered Super C Tournapull with Model LP scraper in both conventional and military colour schemes. Spec Cast is planning to issue a variation of this model minus its cab later in the year.

EMD Models produce a Super C Tournapull (also Cummins powered) with a Model LP scraper. This model is not widely available and was manufactured as a “limited run” item. In some aspects the EMD model is more accurate than Spec Cast’s offering, however, at approximately four times the price, the model collector will have to decide which represents best value for money.

It is a pity no manufacturer has yet chosen to offer the earlier standard C Tournapull.   

Brief specifications

Australian Super C Tournapull (The most common New Zealand version)

  • Engine: General Motors 6-71, six-cylinder, in-line diesel rated at 152 horsepower at 1800 rpm
  • Clutch: Rockford 16” dry plate
  • Transmission: Fuller 4A1120, four speed forward, one reverse
  • Top Speed: Approx 15 mph
  • Brakes: Contracting band type on drive axle
  • Tyres: 21.00 x 24, 20 ply
  • Steering: Heavy duty double cone clutch and contracting band brake
  • Turning Circle: 39’
  • Scraper: LeTourneau model LP-C
  • Capacity: 12.1 cubic yards struck, 15 cubic yards heaped
  • Operation: Cable
  • Length: 32’3”
  • Width: 10’2”
  • Height: 11’2”
  • Operating Weight: 15.5 tons (empty), 32 tons (loaded)

 

Contractor Vol.34  No.5 June 2010
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