About fifty years ago, the first pipeline inspection systems were used to look inside sewer utilities. These early systems were large, heavy, and difficult to pull through pipelines. The cameras were black and white, delivered 325 lines of resolution and required 10 Lux of light to produce a picture.
Technology has advanced considerably and the pipeline inspection and CCTV systems of today bear little resemblance to their early predecessors. The systems are now vital to our present day collection systems.
Pipeline inspection systems can be credited with discovering sewer conditions that otherwise would have resulted in catastrophe. The valuable information collected by these robotic wonders is immeasurable.
Before having eyes in sewer lines, municipalities and contractors exposed problems after it was too late – being reactive rather than proactive resulted in costly repairs. Sewer overflows would spring up, having a tragic impact on the environment.
Inspection systems have saved agencies millions of dollars. Finding defects before they cause overflows or result in sinkholes has helped cut costs significantly, and performing regularly scheduled maintenance has reduced construction costs.
A huge breakthrough came in 2001 when CCTV inspections transitioned from VHS tapes to digital recordings. VHS tapes were bulky, challenging to use, and pinpointing specific locations on videos was time consuming. As a result, most pipeline inspections were put on the shelf and never reviewed.
Digital was a huge upgrade because it offered improved picture quality, and new way to view inspections. Users could look at each line segment of an entire neighborhood in a relatively short period of time. The result was a more informed and sophisticated end-user.
Digital recordings also changed the way pipeline inspections were stored. Instead of huge boxes of VHS tapes, digital inspections could be burned onto CDs and archived. This was a great improvement, but there were still some drawbacks.
Since digital files tended to be very large, one CD could only store a few inspections. As a result, a large number of CDs were needed. It was time consuming and slow to burn each CD.
DVDs were the next major enhancement because they increased the amount of storage space on a disc by more than six and half times that of CDs. The number of discs required for a project was reduced significantly. However, the DVD was also far from being the ideal storage solution. Writing data to a disc took a lot of time and discs could become corrupted during the burning process. CDs and DVDs were also very delicate and could easily be damaged.
Over the past few years, external hard drives have become the preferred method of storage for CCTV inspection files. This has been a huge improvement over previous technologies because a lot of files can be stored on a single device. Hard drives of every size have become relatively inexpensive. Municipalities and contractors can store an entire collection system on a hard drive.
The external hard drive has simplified the process of backing up information. Rather than sitting through the process of burning multiple DVDs, a hard drive can be left to copy and back up all the data files at once. This makes it easier and more likely that important data will be saved regularly.
Flash drives have also gained popularity as a quick and easy solution for small projects. Digital video inspections, reports and JPEGs can be quickly transferred to the drive and given to the customer or agency engineers. Drives allow transfer of a limited number of high-profile inspections for immediate review.
It has become effortless to share information with others using digital recordings. End-users can easily copy information to laptops or other storage devices, allowing more people to be involved in the infrastructure rehabilitation decision process. Instant viewing makes video inspections available for quality control checks and for ongoing pipeline inspection operator training.
CCTV inspections can also be shared with others across the country using digital files. The files can be uploaded to an FTP (file transfer protocol) site or sent over a specialized online courier.
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The overall pipeline inspection process has also evolved over the years. National Association of Sewer Service Companies (NASSCO) has contributed significantly to the advancement with its Pipeline Assessment and Certification Program (PACP). By standardizing the way to identify sewer defects, the organization ensures that everyone is making observations using the same practices. This has helped the end-user clearly understand what is being conveyed within the inspection. It also ensures continuity and consistency of inspection information among operators, agencies and contractors.
During pipeline inspection surveys, defects are rated according to their severity on a NASSCO scale of one to five. Defects rated as a five are considered severe and require immediate attention. Observations rated as threes and fours go on a watch list for future consideration.
As pipeline inspections enter second, third and fourth phases, historical data is merged with current data. The combined information allows users to determine the rate of deterioration of defects and more accurately project when repairs will be needed.
Two things are certain for the future of pipeline inspection cameras. Inspections will continue to evolve and incorporate new technological advances, and they will continue to play a critical role in the assessment and rehabilitation of collection systems.
About the Author
Jim Aanderud is owner of Innerline Engineering, a video pipeline inspection company based in Corona, Calif.