THE CATERPILLAR 793 MINING TRUCKMany collectors will be familiar with Norscots model of the Caterpillar 793 Mining Truck; the latest variant of which, the 793F, was released at this years Toy Fair. Incidentally, the model displayed at Toy Fair was from the initial production run which included a manufacturing fault; the model identification decal was incorrectly positioned on the tipper body.
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CAT 793F on display at Toy Fair 2011 (Cranes Etc, 2011)
The 793 was released by Norscot in 2006 as a ‘D’ variant, with Performance Plus Body, sometimes referred to as the ‘Collectors Version’. This was subsequently followed up in 2007 with a 793D in Caterpillar’s new Power Edge Trade Dress and MSD II (mine specific design) Body. The final variant, the 793F with X Body, was formally released at Toy Fair this year.
The following is a review of the 793 across the three variants offered by Norscot over the past five years.
Caterpillar 793D with Performance Plus BodyThe Performance Plus Body was scheduled for commercial released in late 2005, but never made it onto the market. The theory behind the ‘waffle’ design was to significantly reduce the body weight whilst maintaining stiffness and durability. Performance improvements included:
A grid design that evenly spread stresses whilst reducing flexure and cracking. The lightweight grid inserts decreased vehicle operating weight by eliminating material that would normally accumulate within the grids.
The body featured an S-shaped canopy-front wall-floor transition that spread stress over a larger area, effectively reducing stress concentrations. The S-shaped front of the body was conducive to free material flow, faster material movement out of the body, and less material sticking.
Composite materials were incorporated into the design, including fibreglass canopy sections that were lighter than steel. The substructure was a composed of fibreglass beams and UHMW (ultra high molecular weight) plastic overlay sheeting.
The body had a 4° flare from front to back, with side walls that tipped out, offering a larger shovel target area and less resistance to material flow when dumping.
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Performance Plus Body as shown at MINExpo (taken from internet, unknown source)
Miniature Construction World reviewed Norscots adaptation of the early 793D in 2006 and the review can be found here:
CAT 793D Performance Plus ReviewWhilst the review generally praised the level of detail on the model, it failed to mention the omission of a motor in the truck. In fact not only was the motor missing, but also the transmission, drive shaft and most of the differential or final drives.
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Caterpillar 793D with MSD II BodyMy understanding is that the MSD II Body was under development at the same time as the Performance Plus Body, but ultimately won out due to the lower production cost. Moreover, the MSD II was part of a broader strategy by Caterpillar to give customers greater customisability at the point of manufacture.
The configuration of the MSD II Body is based on the evaluated parameters of a specific mine site, including material density, material abrasiveness, impact potential, type of loading tool, haul road conditions and conditions at the loading and dumping sites. The MSD II Body is tailored to yield the best balance of payload capacity and durability when working at established mine sites, where material density is likely to be consistent.
The 793D with MSD II Body modelled by Norscot was released in Caterpillar’s new ‘Power Edge’ livery, which saw the replacement of the familiar red beltline stripe graphics first introduced in 1991/92. A new more vibrant yellow accompanied new graphics, and the new look was extended across the entire Caterpillar range to enhance product identity.
As with the earlier 793D variant, Miniature Construction World reviewed this updated release, and this can be found here:
CAT 793D MSD II ReviewApart from the body change the model remained exactly the same, even to the extent of omitting a motor, transmission, drive shaft and half the differential. Both this and the previous variant had good levels of detail, for the most part, due to the use of moulded plastic parts.
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DSCN1016 by
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Caterpillar 793F with X BodyIn 2009 Caterpillar released the X Body, designed to offer increased payload, improved durability and extended service life. According to Caterpillar, the X Body featured a high strength but lightweight design that made it ideal for high density, poorly fragmented, materials.
The X Body design improvements included a more robust frame structure and tapered sidewall ribs, aligned with floor ribs to add to the structural integrity of the body. It used a particularly heavy-duty design and accommodated a larger volume than previous Cat dual-slope or flat-floor bodies.
Norscot most recent variant of the 793, the latest ‘F’ Series, features Caterpillar’s X Body. This model has as yet not been reviewed by either Miniature Construction World or Cranes ETC, so I will attempt to provide a brief rundown.
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The upgraded F model features a less cluttered cab deck layout, gone are the air tank and ancillary equipment, replaced with a couple of extinguishers. The deck also features a lift-up panel (similar to the 797F) to access the engine compartment, and euphoria; there is actually an engine under there. Also at the cab deck level are two large exhaust, nice patterned no-slip decking and metal handrails.
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The F Series has a new drivers cab, but unlike the cab on the flagship 797F, there are no lifting lugs on the cab roof. There is an access ladder from the cab deck to the rear of the engine bay.
With the inclusion of an engine and torque converter, additional effort was made to complete the drive train, including a transmission and complete final drives. However, things move slowly at Norscot as a vital component in the motive system is still omitted...no driveshaft. Oh, well maybe on the 793G...or the H...or the...
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The 793F has operable steering complete with steering dampers and increased range of motion over previous variants. The rear suspension has been modelled as it was on previous versions, and works reasonably well.
The X Body includes debris bars and some really nice safety cables designed for locking the body in the upright position, although this is not actually possible on the model. The body includes wear plates and is fitted with multi-stage pistons that do a great job of keeping the body in the raised position.
All in all the 793F is a nice model with a reasonable level of detailing. Where plastic parts are used they match well with the paint finish. On that topic, typical for Norscot models, the paint is both heavy and excessively glossy.
ConclusionFor anyone with a passion for dirt haulers, having all three models illustrates nicely the transition between models. It enables you to trace the evolution of not only the 793, but also Caterpillars corporate image with the Power Edge Trade Dress and the development mine truck tipping bodies.
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What is needed now is for Caterpillar to authorise another truck fitted with a Gateless Coal Body; personally I think a 795F AC would be just the thing, and it would be nice to see an AC drive CAT in the lineup. Then again, with Caterpillar’s immanent takeover of Bucyrus they will inherit a fleet of AC drive trucks, so perhaps the days are numbered for the 795F AC.
Hope you found this interesting and informative. Errors and omissions excepted, if you feel something is incorrect, please let me know.
ChrisPH4100XPC@gmail.com
