ompanies that specialize in Arctic construction spend years perfecting their craft under the harshest conditions. As in many cases in Alaska, logistics plays a huge part of any undertaking.

“Any sort of development starts with the question, ‘How do you get there?’” says Jim Campbell, PE, principal engineer and president of PND Engineers, Inc. “Almost any project that you want to build in the Arctic requires that you build roads. While a small number of projects are roadless, most are not.”

“Building roads to some of these sites is no trivial task, either,” adds PND Principal and Lead Geotechnical Engineer Torsten Mayrberger, PE. For example, on one oil and gas project a company found a considerable amount of oil, but it required a 100-mile access road over extremely rugged terrain and fourteen bridges to reach it. “In that case, it was so expensive to get to the resource that the company had to weigh the costs to determine if it could still be profitable.”

Logistics also affects where a project can be built, especially in cases where soil conditions are unknown, according to Jeremiah Holland, PE, senior geotechnical engineer at DOWL. “Much of the work in the Arctic is done in remote locations where companies may not know the subsurface conditions,” he says. “Before we can start any design, we need to go explore the area with a drill rig or other tools. This requires personnel and equipment, which drives project costs up quickly.”

He gives the example of prospective projects around Nome. “On the shoreline, the soil could be thawed, while on the tundra it may be frozen five feet down,” he says. “That’s why we drill; it’s a challenge to know what we’re dealing with.”

One increasing concern is that the thaw rate has substantially increased over the years, meaning that buildings that were expected to last a certain amount of time are failing at an alarming rate.

“In Nightmute, the school foundation built in the 1980s has failed as a result of the permafrost changing much more rapidly than was originally anticipated,” says Hopper. “When we were hired to build an addition, we found that the bottom of the stairs, which were built at grade in 1984, were now three feet above the ground.”

“You want to provide a design that will last for the building life, and that’s difficult with climatic conditions changing,” says Holland. “It’s a challenge to try to use the latest data to build something that will perform well in the Arctic for the next twenty to thirty years.”

“Sometimes, repairs may require highly skilled individuals that are not available in a village; flying people in to fix things is an added cost,” says Stantec Associate, Senior Architect, and Building Technology Specialist Ross Timm. “That’s why you want to make a building as simple as possible to maintain. That way, the owner may only need to bring in someone once a year from Anchorage or Fairbanks.”

Using the right materials is also important.

“All villages in Alaska are required to have a school, and it’s usually the nicest building in town,” adds Campbell. “While a village may not have a wastewater treatment system or potable water system, when you build the school, you need to provide that infrastructure, which makes it more expensive.”

A lot of Arctic construction is pre-fabricated elsewhere so it can be assembled quickly. “In the Lower 48, material costs drive each project; in the Arctic, labor and transportation costs drive prices,” says Mayrberger. “You reduce the amount of labor, you reduce costs.”

“Up here, there’s a really high value placed on making sure that the environment is protected; we think about minimizing our footprint as well as minimizing when and how we do work so that we don’t disturb fish and animals,” says Campbell. “This affects every aspect of the project—in a good way.”

PND also considers indigenous cultures in its design process. “We want to cause the least disturbance to their daily lives and also show respect for historical sites,” says Mayrberger. “In the whaling season, for example, all barges and marine construction stops. It’s a very cooperative process, and most people take it seriously even without the regulations.”

“During spring break-up, the river is a nasty place,” says Mayrberger. “There are ice floes 30 feet in diameter and 7 feet thick roaring down the river. We had to design the bridge with ice breakers as part of the pier foundation so that the ice could ride up on ramps. There, the weight of the floe causes it to break so it can be redirected from the bridge foundations.”

PND has also designed bridges that can go underwater for a few days during peak flooding, similar to road crossings that go underwater in places vulnerable to flash flooding, like Arizona.

According to Chase Nelson, PE, a DOWL project engineer, in Arctic regions keeping water and wastewater systems above freezing is a challenge, as is protecting the frozen ground around heated water and sewer systems. “Melting the frozen ground and permafrost by introduction of a heated system can have fallout for other infrastructure, like the roadway above the pipes and adjacent buildings,” he explains.

Arctic water systems are designed to maintain constant circulation for freeze protection, and many systems include add-heat systems where the potable water is heated before distribution. Many communities also find ways to keep the water and sewer pipes heated, such as an electric heat trace or a glycol heat trace that accompanies the water and sewer mains.

Nelson adds that all water and sewer mains in the Arctic are designed with insulation around the mainline and an external pipe jacket to keep the fluid inside above freezing while protecting the surrounding frozen ground.

Bethel and many communities with significant ground movement from freeze/thaw cycles engineer aboveground pipes, because ground movement can damage the pipes. Kotzebue, on the other hand, buries its water and sewer mains in the shallow active layer above the permafrost.

“The pump station reservoirs often need to extend well into the permafrost, so the reservoir must be insulated to keep the surrounding permafrost frozen and the wastewater in the wet well above freezing,” explains Nelson, noting that a cooling system is often added to both above and below ground structures.

“The construction season usually runs from January to mid-April, which is a very small window to do a lot of work,” says Campbell. “Unfortunately, the window has been getting smaller in the last few years—April 15 is usually the end of the season.”

There are a lot of challenges with working at this time of year, including below freezing temperatures and darkness. “These temperatures are not good for man or machine,” says Hopper. “We’ve been delayed a month on jobs because of machines breaking. At Eielson Air Force Base we lost a month on a steel frame building because it was too cold to weld. This makes a major impact on scheduling.”

In addition, extreme wind conditions can make it impossible to keep temporary plastic sheeting in place, and lighting sites is also very difficult. Barge schedules and the availability of charter and commercial flights also limit opportunities to get materials in.

Despite the challenges, those who design and construct Arctic buildings find ways to make it work.

“The key word is resiliency—that’s what it’s all about,” says Gambardella. “You design it into whatever the facility is.”