Cat's C15 Easily Handles This Job

Sept. 28, 2010


Driver Ron Zarndt, 44, has been with Catom for nine years and has hauled machinery since he was 18. "This is the nicest truck I've ever had," he says of the fancy KW and its big Cat engine.
The Cat under the hood looks like any other double-turbocharged C15. But this "King of the Hill" version makes as much as 625 horsepower and 2,050 pounds-feet of torque.
A heavy Deere excavator pushes the rig's GCW to 155,000 pounds—a moderate load by Catom Trucking's standards—but the KW and its C15-625 were up for it. All the fleet's 16 tractors are gloss black with lots of bight-metal trim and extra running lights.
The long-hooded W900L also has a 6-inch-longer cab, thanks to the Extended Daycab option. A long wheelbase provides room for big fuel tanks, toolboxes and the pusher axle.
Test Set


Tractor: Kenworth W900L, w/reinforced frame rails, BBC 136 inches w/extended daycab

Engine: Caterpillar C15, 625 hp @ 1,800 rpm/2,050 lbs.-ft. @ 1,200 rpm, w/Brake Saver and Compression Brake

Clutch: Eaton Fuller 15.5-in. 6-spring ceramic w/Easy Pedal

Transmission: Eaton Fuller Roadranger RTLO-20918B 18-speed overdrive, w/cooler

Front axle: 14,600-lb. Dana Spicer E-1462I on taperleafs

Rear axles: 46,000-lb. Dana Spicer DT463P, dual-range w/3.70 and 5.04 ratios, on Neway AD246 air-ride

Pusher axle: 25,000-lb. Watson-Chalin 2200, liftable and non-steerable

Wheelbase: 253 inches

Brakes: Dana Spicer S-cam w/extended service linings and Wabco ABS

Tires & wheels: Bridgestone 11R22.5 on Alcoa polished aluminum discs

Fuel tanks: 150- and 120-gal. polished aluminum

Trailer: 50-ton Talbert 53-foot × 102-in. lowboy w/hydraulic gooseneck

In this story:

Hauling big, heavy machinery is interesting and challenging, but it becomes real work when you're threading your way through the kind of traffic you find in Chicagoland. You've got to keep an eye on your wide load so it doesn't hit vehicles or pedestrians on the streets and highways you must use. Of course, it's also pleasant when you're driving a fancy Kenworth with an engine that's up to the job.

I was here because the 625-hp Caterpillar C15 is the first one installed in a truck, and it's operated by Catom Trucking of Geneva, Ill. It and another just like it are owner Tom Stellman's latest KW-Cat tractors.

Cat announced the C15-625, with 2,050 pounds-feet of torque, last March, and began building it a few months later. It's the most powerful on-highway truck diesel on the market and probably the strongest production engine ever sold, exceeding Cat's now-discontinued 600-hp C-16 and Cummins' Signature 600. Both were pulled when emissions rules changed in October 2002.

Stellman has 16 Kenworth tractors that pull lowboys and flatbeds, carrying construction machinery throughout Chicagoland and into neighboring states and sometimes farther. The rugged tractors and multi-axle trailers are heavy to begin with, and most loads are oversize and overweight. Gross-combination weights are regularly well above 100,000 pounds and sometimes far exceed 200,000 pounds.

Some Catom tractors have the big Cummins 600, but various problems, and a visit to a Caterpillar demonstration in Arizona, made Stellman decide to convert to Cat engines. He's got 550- and 600-hp Cats already in the fleet, and "they have all been productive and maintenance-free," he said, and hopes the "Six-and-a-Quarters" will be, too.

"We could get by without the extra power, but we pride ourselves on giving our drivers the best possible equipment to do their jobs, and the 625 makes it a little easier when you're climbing inclines and pulling heavy loads," says Stellman. He was a driver, but came off the road to manage the fleet full-time.

The two 625-powered W900Ls were bought last summer, and their specifications are identical except for headboards and placement of exhaust stacks. Driver Ron Zarndt, 44, spec'd them both and was assigned to the first one.

Zarndt showed me a typical day's work that for him started at 4:30 on an autumn morning, three and a half hours before I reported in. He had already hauled one load on a Talbert three-axle lowboy with a hydraulic gooseneck; the KW has one liftable pusher axle, which we'd need for the second of two loads we hauled.

Truck-load specs

Our first load was a Rome 89 wheeled pull-scraper, a "pan" in local jargon, which weighed about 60,000 pounds. The second was a John Deere 450LC tracked excavator, which weighed 105,000 pounds. Zarndt said he's been hauling machinery since he was 18, so he loaded the scraper and excavator quickly. Securing them to the lowboy with stout chains and come-alongs, then attaching red flags and yellow banners, took about as much time as maneuvering the bulky equipment aboard.

Both loads were about 12 feet wide and had to be carried over city streets and state highways because booths on the Illinois Tollways in suburban Chicago are too narrow for the loads to squeeze through. Expressways are also mostly off limits, Stellman later explained.

Stop-and-go traffic means a lot of shifting with the Eaton Fuller Super 18-speed. I took the wheel after the scraper was loaded, and split some gears for the fun of it. But it wasn't really necessary because our weight wasn't that high.

To be sure, this KW is no lightweight. Aside from its hefty power train and pusher axle, the long W9 has double frame rails, a two-speed tandem, and a wet kit to operate the hydraulic gooseneck on the lowboy. Toolboxes and a polished aluminum headboard tote chains, binders, bungees, flags and other stuff needed in this business; and there are 270 gallons of fuel and 30 of hydraulic fluid. All together, the tractor weighs about 26,000 pounds, Zarndt said. The trailer on this day weighed about 24,000 pounds with just the standard tridem at the rear of its 53-foot-long frame; stinger and jeep axles can be added to boost its capacity, and tare weight.

Behind the wheel

While hauling the scraper, I found that skipping Low gear and starting in 1st was sufficient to get us moving on anything but an upgrade, and on slight downgrades I could start out in 2nd or 3rd if I let the rig roll a little. With the heavier excavator, Zarndt switched the Spicer dual-range tandem into low; this changed the differentials' gear ratio from 3.70 to 5.04 so we could really pull. The 18-speed was easy to shift. Still, while climbing a short hill, I got lost in the tranny and shifted by mistake from 2nd on the low side to 5th in high. Even the Cat wasn't strong enough to recover from that and the rig stalled; I had to start over from Low gear. "How red's my face?" I asked. "Pretty red," Zarndt said.

Otherwise the big Cat propelled us smartly away from intersections and traffic slowdowns, and kept us moving well at highway speeds on the few open roads we used. "I can usually keep up with any of the trucks around here," he said. "Some of the rock jockies will yell (over the CB), 'Jeez, whata ya got in there?' and I'll say, 'Oh, it's a turned-up 290.' 'Yeah, sure!' they'll say."

He tended to rev the Cat toward 1,800 and 1,900 rpm, whereas I tried to keep it closer to 1,600. Either way, it pulled strongly and smoothly, from about 1,100 all the way to 2,100.

Braking was strong, too. Powerful service brakes are augmented by a Cat Compression Brake, which I used often, and Cat's Brake Saver, which I never touched. Combined retarding horsepower could theoretically be as much as 965, but driveline capacity requires that the compression device be electronically limited to 353, so the total available is 718, according to Cat.

It took about 45 minutes to haul the scraper from a housing site near Geneva, in the western suburbs, to a commercial development near O'Hare Field. Then Zarndt directed me to an industrial site nearby, where he loaded the Deere excavator.

The big, dusty machine's engine had a blown turbo, so great clouds of white smoke poured from its rusted stack as it crawled feebly onto the lowboy. We took it to a Deere dealer in South Holland, near the Indiana line, again using streets and secondary highways.

Rowing through the gears and maneuvering through turns while eyeballing traffic was work. This run was tedious because the excavator's low-slung tracks hung out about a foot and three-quarters on either side of the 102-inch-wide lowboy. I constantly watched them through the mirrors to be sure I didn't clobber anything or anybody.

Following Zarndt's coaching, I hogged two lanes on narrow boulevards and where bridge abutments and other obstacles were close to the travel lanes, sometimes irking motorists who tried to pass on the left or right and occasionally succeeded. But some motorists and all big truckers gave me breaks when I needed maneuvering room.

This run would've been more work except for the Cat's strength and the Kenworth's comfort. I knew there was always plenty of power and torque no matter what the situation. Meanwhile, the KW looked good, rode nicely and maneuvered fairly well, even with a longish 253-inch wheelbase, big hood and forward-set steer axle with its limited wheel cut.

We proceeded through one town after another with a few rural stretches between them, and I had no idea where we were. "Are we almost there?" I kept asking Zarndt, and just like a patient daddy he repeatedly answered, "Almost." That went on for the last half of the two-hour run, and I was a tad tired by the time we got there.

"You're driving back," I told him after he unloaded the smoking Deere at the dealership, and he did. He used the Tollways, which were wide enough for the empty lowboy, though rush-hour traffic made the run home no Sunday stroll.

"This is the nicest truck I've ever had," Zarndt declared as we pulled into Catom's terminal about 6:30 that evening. "And I expect it to stay that way for a while." I'd say the same thing if I were lucky enough to be assigned a rig like this doing a manly job like this. Cat calls its C15-625 the "King of the Hill," and the moniker's fitting, even in the flatlands.