Inspection of railroad track systems and right-of-ways has
been a prime objective for commercial UAS. Burlington Northern and Santa Fe
(BNSF) railroad is one of the FAA’s original Pathfinder program companies,
working to test beyond-line-of-sight technology, training, and safety. In the
October 2016 volume of Inside Unmanned
Systems, Renee Knight profiled the use of UAS in rail inspection and
maintenance. BNSF maintains 32,000 miles of track in the Western U.S., and uses
a variety of inspection tools and techniques. The three primary structures that
are routinely inspected are the ballast structure that supports the rails and
ensures proper water drainage, bridges, and the rails themselves. The ballast
structure is inspected using penetrating radar, while bridges are normally
inspected by crews in lifts or cherry pickers. Rail integrity is normally checked
by vehicle or on foot. However, a UAS can accomplish all of these tasks
remotely, without putting a human in harm’s way, and without requiring the
shut-down of a rail section. UAS increase fidelity of bridge inspections by
providing a visual reference over time that can show changes in the structure.
Ultimately, detailed inspections do not get better than the human eye, but
where routine inspections are required, UAS provide an advantage by being quick
to deploy and safe for the human crews.
UAS can also be used by rail crews and emergency responders
in the event of an accident, by using thermal cameras to scan the cars that
require the greatest amount of cooling. Additionally, if a freight train needs
to stop because of an issue, the crew must check the length of the train –
which could reach up to more than a mile and a half. Utilizing a small UAS to
conduct a visual inspection of the train’s condition would save valuable time.
A current limitation of UAS (outside of regulatory
line-of-sight rules) is the relatively short range of common multi-rotor
aircraft, which are typically battery-powered. High-end commercial models may
reach up to 30 minutes of battery life. In comparison, a manned helicopter
carrying an infrared camera, near-IR camera, and stabilized zoom camera can
cover hundreds of miles in a day, albeit at great cost of fuel and crew (Rail
Engineer, 2011).
Testing beyond-line-of-sight flights to improve U.S.
regulations is already underway, with railway inspections being one of the key
industries to benefit from UAS. We can definitely expect to see regular use of
UAS in the rail industry very soon, which benefits the industry at large with
lessons learned and new technology developments.
References:
Knight, R. (2016, October). Flying the rails. Inside Unmanned Systems, Oct-Nov 2016. Retrieved
from http://insideunmannedsystems.com/flying-the-rails/
Rail Engineer. (2011, July). Bird’s eye view from Network
Rail’s helicopter. Retrieved from http://www.railengineer.uk/2011/07/08/birds-eye-view-from-network-rails-helicopter/
