But that type of precise balance and engineering has propelled the rail industry through decades.
This year, the Union Pacific Railroad is marking its 150th anniversary -- and for much of that time it has linked Le Mars to other parts of the world.
In 1862, President Abraham Lincoln approved the Pacific Railroad Act, authorizing land grants and the issuance of government bonds for the construction of railroads from the Missouri River to the Pacific.
Today, 150 years later, Union Pacific's rail covers two-thirds of the U.S., with more than 32,00 miles of track in 23 states. Its 8,000 locomotives help ship everything from coal to flat-screened TVs across the nation.
Le Mars sees about four Union Pacific trains daily.
Three of them are regular routes: Worthington to Le Mars and back, Sioux City to Le Mars, and Council Bluffs to St. James, Minn.
A fourth UP train coming through may be carrying coal on its way from Wyoming to Minnesota or grain, according to UP spokesman Mark Davis.
A history of carrying America
Across the nation, UP trains serve diverse markets, Davis said.
They carry agricultural products, automotive parts and finished vehicles, chemicals such as ethanol or anhydrous ammonia, industrial products such as wind turbine tower sections and blades, building products such as lumber and sand, clothing, electronics such as computers and mp3 players, and energy products -- mainly coal.
These weren't UP's original fare.
After the last spike was driven into the transcontinental railroad at Promontory Summit, Utah, on May 10, 1869, rail cars began transporting heavy machinery and building products from the East Coast to the West.
In return, goods from the West came eastward.
"When the transcontinental railroad was finished, it literally changed the diet of the country," Davis said. "You had fruits and vegetables that were native or grown in California now being able to be shipped cross-country."
Transporting people by train was a secondary result of that shift, Davis said.
"We saw a huge influx of passengers during the 1930s, '40s and '50s," he said. "Railroads started seeing a decline in passenger service in the '50s because by then your highway systems started to be completed."
Iowa became a corridor for trains -- both east/west traffic and north/south traffic.
The Le Mars rail line was originally laid in 1872 by the St. Paul and Sioux City Railroad, Davis said.
While UP started with steam locomotives powered by coal, today's locomotives are actually hybrids of a sort.
"They're basically like your toy train around the Christmas tree -- they're electric," Davis said.
He explained the UP locomotives use a diesel engine to power an electric generator, which produces electricity. The throttle, which is similar to a dimmer switch on a light at home, is used to give the wheels more or less electricity.
Each pair of wheels on the locomotive has its own electric motor to turn it.
This combination of diesel and electric eliminates the need for a mechanical transmission on train engines, which would have to be extremely complex to handle the weight and power of a train.
The engines that come through Le Mars are about 4,000 horsepower, Davis said.
Sometimes trains have a locomotive on the rear as well, helping push the load -- which are sometimes the equivalent of 300 truckloads.
"We were able to do that technology with computer and radio enhancements," Davis said. "Whatever the engineer does is what happens on that back one -- there's no one back there."
The switch from the original steam engines to the diesel and electric engines was complete by the early 1960s, Davis said.
Today's challenge, he said, is to strive for efficiency and reduce emissions.
"Diesel fuel cost for us is our most cost in operating the railroad," Davis said. "We go through over 1 million gallons in diesel every day systemwide."
A crew of two
While trains can stretch about a mile long and weigh thousands of tons, train crews are usually made up of two people: the engineer and the conductor.
"The engineer is much like he was back in the 1800s," Davis said.
The engineer operates the train, carefully assessing the coming path to determine his use of the throttle and air brakes.
This is a delicate balance, Davis said.
"We're able to move so many cars with so few locomotives because there's very little friction going down the rail," he explained. "You have very, very little resistance."
The area of contact between railcar wheels and the rail is the thickness of a dime, less than 2 millimeters, Davis said.
"It's like ice; you just slide," he said. "A 100-car train traveling 60 mph could take 1 1/2 miles to stop."
That's why the engineer's understanding of the train's physics and the rail is so essential, Davis said.
"It's a skill as an engineer to know how the railroad is laid out -- is it hills, is it flat, as I come around this curve, do I have to slow down," he said, adding that an engineer may plan for a slow down 10 miles in advance.
The second crewman, the conductor, handles the paperwork for all the cars the locomotives are pulling -- keeping track of where they are to be dropped off or picked up.
The conductor also helps change the rail switches if the train needs to pull onto a side track or change directions.
Transporting by rail is different than by road.
For one thing, there is usually just one rail line between two points -- meaning getting one train past another takes some maneuvering.
On a single rail track, there will be side tracks at various points to allow a train to stop and allow another train to pass. These side tracks can be 1 1/2 to 2 miles long, Davis said.
A dispatcher will notify a train crew that the train is required to get into the side track to allow a higher-priority train to go by.
"Once that train goes by, they can get back on the main line and keep going," Davis said.
Light signals along the railway help communicate this with train crews, he said.
Some rail switches, portions of rail that shift to move trains from one track to another, are electronic, and the dispatcher can move them from afar.
Other switches have to be manually changed. To do so, the train will stop and allow the conductor to get off and move the switches. The train will then pull ahead onto the new rail and stop again, waiting for the conductor to change the switch back for the next train.
Turning around is another challenge.
Locomotives can't just flip a U-turn.
There are several methods to turn them around. One is a turntable -- a large rotating circle surface with tracks on it that the engine could pull onto and be turned either back onto the track it came from or onto another track.
Another method of turning is a Y-track, which basically allows a locomotive to make a two-point turn and head back in the direction the train came from.
Thirdly, locomotives may be paired, linked back to back, so that when the train gets to the end of its route heading one direction, the second locomotive will be pointed the right direction to take the next load in the direction from which they came.
On the rail, speed limits are suggested by the Federal Railroad Administration and put in place by the railroad companies themselves, Davis explained.
In the country around Le Mars, trains travel up to 49 mph, he said.
In parts of Le Mars, UP has a speed limit of 10 mph because of the intersection of two rail lines, he noted.
Down the tracks
While marking the railroad company's 150th anniversary, UP leaders are also looking to the future.
UP is constantly seeking new markets to offer rail shipment, Davis said.
For example, the company has begun venturing into carrying wind turbine tower pieces and blades by train, including many to Manley, Iowa.
"It's our challenge to find those niche markets," Davis said.
A year to celebrate
Headquartered in Omaha, Neb., UP is now part of 7,300 communities across the U.S.
The company is asking people across the nation to help mark its 150th anniversary.
UP is collecting people's personal stories that tie into UP's history. People can submit written, video or photo stories at www.up150.com.
Also, people can re-make an old "Great Big Rolling Railroad" UP commercial for a chance to win thousands of dollars.
Thirdly, city leaders can apply to appear on UP's Train Town USA registry. The registry, open to all incorporated communities located along Union Pacific tracks or terminals, will feature the communities at www.UP150.com, and they will also be recognized with a resolution from Union Pacific Chairman Jim Young that can be presented to the mayor or city council.
For more history, people can also visit the Union Pacific Railroad Museum, which opened in 2003, in Council Bluffs.
Also this year, one of UP's restored steam locomotives will be traveling the rail, including a stop at the Iowa State Fair in Des Moines.
Or, for local residents stopped at a railroad crossing, waiting for a train to pass, they can see how UP will really mark its 150th anniversary -- by keeping on rolling across America.