Caterpillar Up, Up and Away
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• On a different note, we spent a couple of days with Caterpillar's latest 550, hauling a loaded trailer at 80,000 pounds (36.3 tonnes). This test jaunt was based out of Las Vegas, where Kenworth engineers had been running some hot climate, full-load tests on a W9001 long-nose Kenworth Conventional. So you can bet the weather was hot.
We opted to head for the cooler country. Running up into the Spring Mountains northwest of the city and looping on and up Mt CharIston took us to about 10,000ft in short order. Here the 550 Caterpillar with its tremendous peak torque of 1,850Ibft (2,509Nm) and the 18-speed Eaton Fuller transmission really came into their own. There was no situation where we didn't have the perfect gear, and no grade where we couldn't accelerate and pick up several gears between the twisting switchback curves. High-torque, high-horsepower trucks like this Kenworth/Caterpillar are awesome in the way they can pick up a loaded trailer and fling the combination upwards on a 6% or steeper grade. More importantly, they give the driver enormous performance reserves so that if he fluffs a gearchange it's easy to drop down a gear or two, pick up the rhythm again and work back up to speed even with a big load on the back.
For heavy-haul and logging operations at high gross weights and where journey times are the critical factor, engines like this big Cat are undoubtedly the way to go.
For logging, the 3406E with a Jake compression brake and Cat's own hydraulic Brakesaver offer considerable margins for downhill safety, too. Big horses like the 550 give the sort of performance that endeared the K Model Cummins and the 3408 to on/off-highway truckers of old, except these new generation electronic engines seem to pull even better. They also use a lot less fuel and save as much as 1,00016 (454kg) over those huge old dinosaurs.