Dairy farmer Robert Martin from Chambersburg, PA followed in his father's footsteps when he started his own farming operation over 25 years ago. Over the years, his farm has grown and his interest in farming has evolved into more than just a business. Martin has also found a hobby in the farming world.

Martin and sons Robert Jr. and Joshua found a sport in what's commonly called "pulling." These dairy farmers aren't pulling cattle, but using their refurbished John Deere tractors to test how much weight their machines can handle. Martin takes his two renovated tractors to pulling competitions throughout the country and even takes home a few prizes for the hard work of his two machines. Martin's list of accolades include a 1st place finish in the National Farm Machinery Show, 3rd place finish in the National Farm Machinery Show finals, and a 4th place finish in the Grand National Circuit.

Martin continues to be invited to contests around the nation-and it's not easy to get invited, according to Martin. Only about 30-40 tractors get invited to participate in the two pulling classes for each competition, he said. Martin's Deeres have competed in both the pro stock and super stock classes.

Pro stock machines are allowed to have a bigger engine, but less turbo, while tractors in the super stock class are allowed four turbos, Martin explained.

Speaking of power, Martin's machines have to pack a lot of drive and strength to pull their weight in the competitions. The tractors usually look like your regular farm tractor on the outside, Martin said. However, take a look under the hood and you might be surprised. The engines get bigger and usually a bigger injection is added. Everything from the original tractor is pretty much done over, Martin said. As for Martin's machines, the bigger tractor competes with a 680-cubic inch engine that churns out 1,800-2,000 horsepower. It's not easy producing a pulling machine and the work can be costly. Depending on the extent of the changes, the renovated tractors can cost from $35,000 to $100,000.

The cost and work done on the tractors is worth it to Martin, not only for the prize money and fun of pulling in competitions, but Martin and his wife Patsy get the added bonus of traveling the country.

"Being a dairy farmer, you don't get away a lot," Martin said.