Trenchless technology, the method of subsurface construction requiring little or no continuous trenching, began over 40 years ago. It was invented by Eric Wood. The first recorded tools to repair and replace underground pipelines came into service in the 1970s.
Here is a brief look at the history of trenchless tech.
The Invention of Cured-in-Place Pipe
Trenchless technology began in 1970 when an Englishman by the name of Eric Wood developed the first cured-in-place piping. Wood, who was an agricultural engineer at the time, needed to repair an air duct above a mushroom bed. Removing and replacing the pipe was out of the question, forcing Wood to develop a new technique to complete the necessary repairs.
As a response, he developed cured-in-place plumbing to run through the existing line. He used a felt tube impregnated with resin. By wrapping it in plastic, he was able to pull it through the 230-feet of the pipeline. Once in place, he used air to expand the new pipe and allowed it to harden naturally. The result was a new line encased in the original plumbing and ready for use.
Despite his ingenuity, the plumbing world was skeptical of the long-term use of this new technique. The group worked hard to educate and license workers.
While cities and municipalities saw virtue in their method, due to competitive bidding regulations, the team had a hard time gaining projects as there were no other companies using the same system to bid against. Finally, instead of bidding contracts, some cities decided to negotiate contracts with licensed technicians.
It was five years before the first CIPP project occurred in North America. Almost a full decade after Wood invented the technique and formed Insituform; the group was able to expand to North America.
After the patents ran out in the early 1990’s, more companies began to adopt CIPP as a pipe repair technique.
Development of other Methods
CIPP may be one of the oldest, most reliable forms of trenchless technology, but it is far from the only one. Pipe bursting came into its own during the mid-1970s. While some contractors developed equipment for breaking up existing pipe, there was nothing mainstream. (Learn more in "An Introduction to Pipe Bursting.")
In 1977, the United Kingdom needed thousands of defective cast-iron pipes replaced. In response to the question of how to do this and be economical, British Gas working with the engineering company DJ Ryan developed a method of bursting old pipes.
By the early 1980s, the group was using soil displacement hammers, known as impact moles, and a horizontal ramming machine to break up the existing pipes. The company pulled new tube into place behind the old without having to expose the entire line.
DJ Ryan and British Gas applied for and were granted their patent in 1981. Because of the patent, many manufacturers were reluctant to sign required licensing agreements. With the technical transfer fees and royalties needed for each installed meter, it took several years for the pipe bursting method to gain a broad application outside the United Kingdom.
By the mid-1980s The United States began using the process. Pipe bursting has grown to be one of the most common replacement techniques to update failing sanitary sewer systems.
The Invention of Microtunneling
Developed in the early 1970s in Japan, microtunneling became an efficient technique for sewage pipe installation. By 1984, the United States had adopted this method and used it for the first time in Florida to install a new 600-foot-long, 72-inch diameter sewer line under I-95.
Initially, microtunneling design was for use with gravity sewer lines. However, since its development, workers employ the technique to install all utility lines, especially in environmentally sensitive areas.
Trenchless Technology Gains Popularity
It took time for trenchless technology to take off. However, once city workers realized the benefits of using these techniques, they became the most popular choice when making repairs or upgrades to city infrastructure. (Read on in "A Look at CIPP and Aging Drinking Water Infrastructure.")
Municipalities discovered that they no longer had to excavate sites to repair damaged pipes fully. Less time spent digging out the lines means less cost. Less repair to the grounds, roads, and walkways also means cheaper replacements.
Despite concerns that CIPP repairs may not be as stable as a new pipe, this method delivers high-quality results. Manufacturers of CIPP guarantee their lines hold against corrosion and the environment for 50-years, a longer lifespan than current tubing. Additionally, trenchless methods are versatile enough to work with any plumbing. (Also see "The Lifespan of Steel, Clay, Plastic & Composite Pipes.")
Innovative minds have helped to create a way to repair pipe running underneath the ground without disturbing the soil above it. New methods of trenchless repair and construction are guaranteed to be on the horizon as technology improves.