As part of the development of the Trans-Alaska Pipeline ill the mid-1970s, a pioneer read was built by oil company contractors to allow the movement of material and equipment for the pipeline's construction. Over time, that road was improved and expanded and eventually became Dalton Highway 11. Running nearly 500 miles, it serves as the lone artery between Fairbanks in the south and Prudhoe Bay in the north.

As such, it's a vital thoroughfare, even though much of the area through which the road is laid remains virtual wilderness. The road must be passable year round, however, and making sure it remains that way is a full-time job for the Alaska Dept. of Transportation (ADOT).

To do that, a series of seven road camps were established, with colorful names such as Deadhorse, Coldfoot, Chandalar and Jim River. The road camps, all but one of which are north of the Arctic Circle, are completely self-contained, incorporating water and sewer plants, heavy equipment and truck shops, camp maintenance shops and crew housing.

Each camp operates a fleet of graders, dozers, backhoes, Class 8 tractors with end, belly and side dumps, one-way plows, sanders and lowboys. Highway crews of four to seven men work six 11-hour days and one 9-hour day for a 75-hour week, followed by a week off when they are supplanted by a second crew. There is also a staff of four roving operators and four maintenance technicians. Aside from the rovers, each crew is assigned to a specific camp
and the camps operate year-round.

Needless to say, as most of the camps are surrounded by miles of wild land, they are well off any utility grid. Instead, each of the camps include a dedicated powerhouse that encompasses two engine generator sets. In 1993, shortly after being hired, one of the rovers on the maintenance side, Ernie Searing, was assigned to review each of the camps' facilities and develop a uniform spec. "My boss, Dan Moody, who was the Dalton Highway Camp maintenance chief, said here's your truck, survey all the camp powerhouses," Searing noted. "Come back in a week and tell me what we need."

During his survey, Searing said he saw "every color and size" of gen-set "just about all worn out and none really installed right even to the powerhouse layouts.

"All the camps had about the same load demand, so the master plan was all the gen-sets and all the powerhouses would be set up the same. As this is a 24 hour operation, yearround and the entire camp is dependent on electricity, we went pretty much first class with the idea of long term operation and lifetime on units. "

Ultimately, the project was spec'd out, put up for bid and Cummins Northwest in Anchorage got the job. Over the course of the next four years, four new powerhouses were built, two were remodeled and updated and eight new gen-sets were installed.

In addition to the permanently installed gen-sets, Dalton Highway also has three portable emergency gen-sets. Two are John Deere 100 kW units fully self-contained and mounted in vans, while the third is a skid-mounted Caterpillar 3306 gen set rated 185 kW. "We can haul an emergency unit to the site and hook-up is less than five minutes, Searing noted.

The new gen-sets consisted of Cummins L10 diesels that include Fleetguard two stage air filters connected to the engine turbos through Dynaflex Products 4 in. aluminum tubing. On the other end, Dynaflex also supplied the 5 in. stainless tubing, fitting, clamps, ells, stack extensions and exhaust mufflers Other engine accessories included Engineered Products restriction indicator; Nelson crankcase emissions absorbers; Dwyer Instruments manometers; and Isspro pyrometers and thermocouples.

Engine instrumentation includes coolant temperature, fuel pressure and oil pressure gauges packaged in a panel by FWMurphy that is mounted to the engine on Lord shock mounts. Other instrumentation includes an ENM hourmeter and an Engineering Concepts Unlimited (ECU) ECU88N control module that incorporates a manual start/stop switch, hi-lo speed switch and auto shutdown LED indicators.

The engines drive six-pole Kato 6P2-1325 alternators rated 130 kW, 165 kVA, 277/480V, three-phase, 60 Hz, with bolt on bus bars in the junction box. Operating speed is 1200 rpm. Voltage control is through Basler Electric APR63-5 voltage regulators with remote voltage adjustment, remote field switching and red LED indicator when energized. Crompton Instruments provided electric meters, transducers and transformers.

The switchgear, 400 Amp TPDT, main circuit breakers and enclosures, motor starters, waste heat exchanger circulation pump motor controllers, powerhouse panel boards and main distribution panels were supplied by Square-D and thermostats and other sensors were from Honeywell.

Not surprisingly, considering the climate--winter temperatures can exceed--70[degrees]F--thermal management is a major challenge. "Preferred powerhouse construction is up on pilings, leaving the ground below frozen," said Searing. "If it's on the ground, then some mechanical method of keeping ground frozen must be used. Permafrost ice heave and melt will kill your project.