Sellin Brothers Creates Diverging Diamond in Minnesota
Sellin Brothers (SBI) has the $13.6 million Interstate 94/ Highway 75-area project in Moorhead, Minnesota, on track for opening later this fall. The Hawley, Minnesota, company has met a series of benchmarks.
As the prime contractor, SBI began work in April 2016 for the Minnesota Department of Transportation (MnDOT). The scope of work includes building a half-mile long auxiliary lane to I-94 from Highway 75 to 20th Street to facilitate merging, acceleration and deceleration between ramps; resurfacing about a half-mile section of Highway 75 between 22nd and 35th avenues; and reconfiguring the I-94/ Highway 75 overpass into a diverging diamond interchange.
The department chose the diverging diamond after considering three options and listening to stakeholders. The diverging diamond offered the lowest construction costs and eliminated left turn conflicts, which can improve safety and reduce delays. It also simplified signal phasing and might lower the cost of future corridor improvements. It will be new for drivers, including snowplow drivers, to adjust to, but the concept has been implemented in other places with no problems. MnDOT is adding diverging diamond interchanges in several locations.
The project is sequenced and completed in four phases. Starting in September, projects gradually opened to the public.
"It's a tough project with tight timelines," says David Swafford, Project Manager, with SBI.
SBI removed the old roadway, and rebuilt subgrade and storm sewer, with traffic continuing to flow. The company also created a pedestrian pathway. A 4-foot soil correction exists under the precast box culvert with a ramp built on top of that.
To complete the project, SBI is using multiple bulldozers, backhoes, wheel loaders, skid steers, trucks and tractors.
"If there was one piece this project screamed for, it would be a dozer," Swafford says.
The old concrete pavement is being recycled. SBI hauls concrete to a nearby site, and a secondary company crushes and sells it.
Swafford considers the interstate portion of the project the most challenging. Crews worked during the day with traffic flowing and then completed other aspects at night, when a lane could be closed. MnDOT charged SBI lane rental to close interstate lanes and ramps. Each ramp was charged a different amount based on traffic volumes.
"We have guys at it day and night," Swafford says. "It was three weeks with two shifts working 24 hours a day."
SBI subcontracted the concrete paving on the job to PCiRoads of St. Michael, Minnesota. The tight sequencing has required extensive coordination with all subcontractors.
"The schedule has been a challenge since day one," says Scott Sellin, Vice President for Highway with Sellin Brothers. "This is probably the biggest job we have done in our company."
Sellin Brothers typically handles road, drainage and dirt work but not the paving.
"We like to say, "˜we bake the cake, and someone else frosts it,'" says Mark Sellin, President of SBI.
Last year, Sellin completed another MnDOT project on Hwy 75 in the Moorhead area, a $2.9 million expansion of the highway.
A Growing Family Company
Twin brothers, Harold and Roy Sellin started the family-owned SBI as a small road building company on a farm in 1947. They began by working on township roads. Gradually, the company added equipment and grew into a road and earth-moving firm.
The company formed an underground division in 1978, placing sewer, water and storm sewer utilities. SBI built a new shop in 1981 and a wash bay and cold storage facility in 2003.
The second generation now manages the company, which employs approximately 60 people during the April through November construction season. The veteran corps of laborers includes people who have worked for Sellin for 30 or more years.
"We pride ourselves on retaining our folks," Mark Sellin says. "We have had employees start at 18 or 19 years old and retire with us."
In the winter, the company performs snow removal and services the fleet of equipment with about 15 people. The full-time maintenance shop works all winter. Most of SBI's projects are in Minnesota and eastern North Dakota, about a 200-mile radius from Hawley.
"We go where the work dictates we go," Mark Sellin says.
SBI uses the latest equipment and technology while employing skilled personnel. It lives by its core values of skill, responsibility and integrity.
"You have to have the right people in place to succeed," adds Mark Sellin. "From the bottom up and top down, people are the key."
When the company began, a lot of the work consisted of new roads. Now the projects are mostly rehabilitation work, which must be constructed with traffic flowing.
Dependent on the Latest Equipment
SBI has a long-standing relationship with General Equipment & Supplies in Fargo, North Dakota, and one of its sales representatives, John Gromatka, who has worked with SBI for decades.
"When we need something, we pick up the phone and get what we need, service, parts, whatever," Mark Sellin says. "John is the only representative we have known. Our relationship is very strong."
General Equipment & Supplies sells and rents heavy equipment for the construction and aggregate industries. It also offers parts and services. Service technicians and parts specialists are available 24 hours a day, seven days a week to keep customers' equipment up and running.
The SBI team takes its equipment seriously and upgrades the fleet regularly. It relies on GPS systems to become more time and cost efficient with recommendations from General Equipment & Supplies about how best to keep its machinery up to date and able to draw on technology to enhance production.
"We've had models built for all of the dozers, and it has saved us a lot on staking and finishing costs," says Swafford. "The operator can visualize what's in front of him and how to build it. I don't know what we would do without it. We would need three more people, at least."