Image: Very early production Caterpillar D10 goes about its business in some fairly heavy rock, a normal operating environment for this machine when it first appeared in 1978. PHOTO: INTERNET
When it was first introduced to the world in 1977, the Caterpillar D10 raised a few
eyebrows. First, because of the machines sheer size, and second the odd configuration of its undercarriage. By Richard Campbell.
The concept of an elevated sprocket drive mechanism was not a new one and, in fact, dated back to the C.L. Best (a forerunner company of Caterpillar) model 45 ‘Humpback’ of 1914 vintage.
But, it was not until Caterpillar introduced its D10 that the concept once again came to public attention.
Caterpillar began serious design investigation of what was to become the D10 in 1969 in an industry-wide response for a tractor larger than the (then) current model D9G.
Interestingly, the idea of a tractor larger than the D9 was mooted as far back as 1955 when that model type first appeared.
Beginning in 1973, several test mules were constructed to prove some of the concepts designs and to iron out any bugs that would invariably appear in a new machine, especially one as large and radical as the D10.
Test machines were sent to selected contractors’ jobs and others were shipped from Peoria to Caterpillar’s Arizona proving ground where several were worked to destruction to determine component life expectancies.
Introduction
Officially unveiled to the public in September 1977, the first deliveries of the new Caterpillar D10 (84W series) did not take place until the first quarter of 1978.
The new machine was welcomed by large construction companies and mining contractors alike, as now they had a machine large enough to shift bulk earth and rip material that previously had to be blasted!
There were a few ‘hiccups’ however, probably as to be expected, and a revision was made very early on to replace the single large exhaust pipe with two separate stacks one either side of the bonnet. This reduced heat buildup in the turbocharger area and therefore also improved the machines exhaust back pressure.
Consideration had obviously been given to this problem by the factory design team as the machine came delivered from the factory with a fire suppression system in the engine bay as standard.
Sales of the D10 were very strong and, at one point, Caterpillar had a quite a waiting list for new machines as the demand was that great.
Tipping the scales at some 64 metric tons bare, the initial production model of the Caterpillar D10 was powered by a 700 flywheel horsepower Cat D348TA twin turbocharged V12 diesel mated to a Caterpillar barrel-type 3f/3r planetary powershift transmission.
One of Caterpillar design teams principal considerations when designing the D10 was ease of servicing and, to this end, the transmission or final drives could be extracted very easily in just over an hour due to the modular design of the tractor.
Independent bogies held the bottom track rollers, and these allowed the tracks to wrap over an obstacle rather than ramp up on it, reducing point loading on the tracks and adding to the machine’s traction.
There was a track idler at both ends of the track frame and track tension was maintained by a very large hydraulically adjusted recoil cylinder.
The track frames were entirely independent of the final drives and were held in place by a very substantial pivot shaft at the rear and a conventional equaliser bar at the front that allowed track frame oscillation.
This arrangement prevented any shock loads being transmitted to the machine’s final drives.
We cannot forget the operator
Isolation mounted from the tractor frame was the operator’s compartment featuring a comfortable suspension seat angled off at around 30-degrees to the right to allow easy visibility to the ripper and blade.
The entire interior was very well-laid out and obviously the folks at Caterpillar had put a lot of thought into its design with all the control levers featuring short throws and closely grouped to minimize operator fatigue.
No pedals or levers penetrated the floor plate, allowing easy access in and out of the cab with the added benefit of heat, dust and noise reduction to those machines fitted with a ROPS cab.
The Caterpillar D10 was a real ‘operator’s machine’ and spoken of highly by all who operated them.
Attachments for your D10
Caterpillar offered several blades to outfit the D10 including a 10S straight blade, 10U full U-blade and the 10C, which was a special cushioned push blade for push loading large scrapers.
This often came with a special cushioned push plate fitted to the rear of the tractor for tandem pushing duties. No angle blades were offered.
Rippers included a fully adjustable single shank type and a multi shank model.
An impact ripper was offered for a time, but this seems to have been discontinued.
D10’s could be equipped with a fully enclosed ROPS cab or an open ROPS for those machines operating in warmer climes.
Following the introduction of the D10, the entire Caterpillar range of track type tractors received the elevated sprocket design with the exception of the D3.
The initial production model, the 84W series was discontinued in 1986 following a design revision which included engine changes, weight revisions and resulted in the D10L and D10N.
Subsequent versions of the machine have included the D10R and the current production version, the D10T2 but these fall outside the scope of this article.
For the model collector
Good news, as for once, there is quite a bit of choice when it comes to models of the Caterpillar D10.
Several model manufacturers including Conrad, Norscot, Diecast Masters and Classic Construction Models have all produced versions of the D10, D10N, D10R and D10T over the years to 1:50 scale.
These vary in levels of quality with the Diecast Masters and Classic Construction Models’ examples definitely the pick of the bunch.
For the budget conscious collector there is also a 1:70 scale model produced by Joal.