While a great many of LeTourneau’s inventions were designed for earthmoving purposes, some of his creations had very practical applications elsewhere. By RICHARD CAMPBELL
There is a very old saying “necessity is the mother of invention”.
This is particularly relevant when describing the development of the Le Tourneau Tournacranes and their evolution.
Le Tourneau designed and built his first proper crane around 1933-1934 in direct response to a need in constructing his new manufacturing shop buildings.
It was fabricated from box and channel section steel welded together (of course) and had a nominal capacity of around 10 tons at close radius.
Riding on steel wheels, the crane was operated by cable control from the back of a track type tractor to which it was attached.
It was highly effective and despite being a ‘trailer-type’ crane, was very manoeverable.
The word was not long in getting around about this useful crane and soon orders began to roll in from customers who also wanted one.
At the time, almost all cranes were based on a rigid crawler frame and had very slow walking speeds. It was also recommended that they not travel with a suspended load.
Never slow in picking up on an opportunity, Le Tourneau refined his design a little and began manufacturing the cranes for sale.
Equipped with either steel or Le Tourneau’s newly developed low pressure pneumatic rubber tyres, the cranes sold in great numbers and gained a reputation for their strength and reliability.
The crane could be used on rough ground without surface preparation and could travel with a load suspended.
Towed Tournacranes were soon available for use behind Caterpillar tractors from D4 to D8 size.
The towed Tournacrane was eventually phased out in 1953.
With the introduction of LeTourneau’s revolutionary Tournapull in 1937, this opened up a whole new opportunity for crane development and sales.
One of the added beauty of these cranes was they could traverse ground where a standard truck mounted or crawler crane just couldn’t go, and could do it with a suspended load to boot.
These new cranes were fabricated from welded tubular steel and operated from the Tournapull’s own PCU with lifting capacities ranging from 10 to 30 tons.
Even the military were interested in the new self-propelled Tournacranes, realizing correctly, their great potential.
The United States Army Air Force (USAAF) ordered several Model B Tournacranes for use at large bomber bases where they were employed as crash removal machines, being able to clear a runway much faster than by current means of the day.
As an example, a Model B Tournacrane could lift a B-24 Liberator bomber no problem at all and trundle off with it to the bases repair facility (or scrap pile).
A special crane was developed for the air-transportable Model D Tournapull which was designed for the US Army in 1944
This crane had a lift capacity of 5 tons and, following the end of WWII, was continued in production for the civil version of the machine, however very few were actually built.
Following the War, the new generation of electrically-controlled Tournapulls began to appear.
These added a whole new dimension to the Tournacrane by introducing one of the very first modular concepts for construction equipment.
To expand on this modular concept, we have to take a look at how the post-1946 Tournapull tractors were designed.
The Tournapull itself was a self-contained tractor unit to which trailing devices could be attached.
All one had to do was choose the trailed item to be mated to the Tournapull, insert and tighten up four large bolts and plug in the electrical harness cable and brake air line.
It was as easy as that.
Average switch-over time from one trailed item to another was around 2 hours, with the correct blocking equipment and tools.
This allowed the contractor great flexibility in the use of his machine as one Tournapull could fulfill the roles of motor scraper, rear dumper, flat bed trailer or crane without having to purchase four separate, dedicated machines.
It was an idea years ahead of its time.
All four new Tournapulls, Model A, B, C and D had their own crane attachment.
This was a great time for LeTourneau as they had a pretty captive market for off-highway cranes as no other manufacturer’s offerings came close to the Tournacranes’ capabilities.
One of the added benefits of electric operation was a more precise control over the cranes functions than was previously possible with a PCU.
If the former model cable control unit’s brake bands were a little worn, this could (and did) result in the suspended load shifting downwards by gravity at inopportune moments.
The multi-disc brake units on the new Tournatorque electric motors eliminated this scenario entirely.
In fact, the only way the load could be lowered was by the operator flicking the switch or if the cable broke!
In 1953, LeTourneau sold his company to Westinghouse Air Brake Co.
Production of the Tournacrane attachments continued under the new regime, the only difference being the company logo which now read “LeTourneau-Westinghouse”. This would later be changed in the mid-1960s to the more simplified “LeTourn” (Americans just love using acronyms).
Due to the excellent design and performance of the cranes, Westinghouse made very few adjustments to the line over the years.
However the 1960s saw an upsurge in the number of crane manufacturers building off-highway type cranes.
The likes of Austin-Western, Pettibone and Grove all introduced rough terrain cranes during this time period and these would be later followed by other manufacturers.
This had a direct impact on LeTourneau-Westinghouses’ sales and demand for the Tournacranes began to decline.
The electric control Tournacrane was officially removed from production during 1967 when Wabco introduced their new 200 and 300 series scraper tractors.
These were hydraulically operated, and due to the design of their gooseneck, would not accept interchangeable attachments.
The era of the Tournacrane had come to an end – but not quite.
Wabco had one last go at creating a mobile crane out of a Model 222G tractor unit equipped with an all new crane.. Only a handful of these were built before the idea was put to rest.
The New Zealand Connection
One example of a Model C Tournacrane is known to have been imported into NZ.
This was originally sold to Dryden Construction of Auckland and used at Wellington Airport to move concrete blocks and Tetrapods from the concrete casting yard to the traveling crane which placed them along the breakwater.
This was sent back to Auckland after assignment and was eventually sold on to J.R.Williamson.
It languished for many years in a yard in Penrose before being bought by Rob Marsh who restored it back to life and sent it to work in New Plymouth.
Its ultimate fate is unknown. Anybody out there fill in the blanks ?
For the Model Collector
Not one example of a model Tournacrane exists in any scale to the very best of the author’s knowledge.
In fact, models of LeTourneau/Wabco equipment per-se are practically non-existent.
This probably has something to do with stupid licensing rights but it is hoped that something may be done to resolve this oversight.