The Model C Tournapull: an overview by Richard Campbell
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
Legend 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).
His 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
As 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 21.00×24 on the tractor and either two 21.00×24 or four 18.00×24 on the scraper.
The top speed of the unit was around 15 miles per hour.
On 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.
Негізгі бет Classic Machines : LeTourneau's Model C Tournapull
No video
Пікірлер: 7