Three Eagle Ford Companies have broken a national oil industry record by moving a massive amount of frac sand by rail.

Related: Supply Chain Initiative Launched for Bakken

Unimin Energy Solutions, Union Pacific Railroad and Twin Eagle Sand Logistics moved 14,000 tons of frac sand on July 4th weekend. The 140 cars measured 6,200 feet long and were powered by four diesel engines. The shipment was certified by Union Pacific as the largest single frac sand rail delivery in the United States.

This event is significant because it shows the continued improvements in all aspects of the oil and gas industry, including supply chain efficiency.

Twin Eagle Senior Vice President Jason Jennaro told the San Antonio Business Journal that it is a challenging market but the number of sand unit trains that have landed at the company's terminals have doubled or tripled so far in 2015. 

Getting the sand to its final destination is another logistics feat. Company officials said it takes four to five 18-wheelers at least 94 truck trips to haul enough sand to a drilling site.