piping was installed below Front Street.

"We're basically putting a new sewer system through the 14-and-a-half-inch pipeline that handles all of the sewage from the cruise ships and the western end of town,'' said Mr. Barry L'Heureux, operations manager of the Canadian company that is installing the tubing.

"But rather than digging up the street and tearing out the old pipe, we'll be pushing the new one down the street using water pressure,'' he said.

The new piping, known commercially as Insitutube, has to be stored in ice before placement, Mr. L'Heureux explained, adding that it was "impregnated'' with a special resin that causes it to harden when heated.

Before any heat was applied, one end of the tube, which resembled a giant fire chute in its limp form, was folded into a sleeve and filled with lukewarm water.

As the water pressure rose, the piping was pushed from its starting point at Number One Shed to its final destination at the foot of Burnaby Street.

In the process, the polyurethane tubing inverted itself, trapping the water in the fold of the sleeve and exposing its resin-washed inside.

The new pipe is created when the temperature of the water is increased and the resin hardens.

"We won't heat the water to 120 degrees Fahrenheit in the first hour and 15 minutes,'' Mr. L'Heureux said. "If we bring the temperature up too fast, we won't get the desired (chemical) reaction. After an hour and 15 minutes has passed, we then turn the temperature up to 130 or 135 degrees, keep it there for two-and-a-half hours and slowly bring it back down to 120.

"At that time, the resin will have fully hardened, and we can cut off the ends at either side of the pipe. We call that part cutting the tail and elbow.'' In addition to accomplishing its task without the need to tear up existing roadways, Insitutube technology has also proven to be highly reliable.

Devised in Britain but American-owned, it can last well beyond its guaranteed "working'' life of approximately 20 years.

"The first Insitutube, which was installed in 1971 in London, is still functioning,'' said Mr. L'Heureux, whose company, Mar-Tech Insituform of Surrey, British Columbia, is well-versed in the product.

But the tubing does have its drawbacks.

Mr. L'Heureux said it should not be regarded as a "be-all or end-all. If a pipe should be circular and it's actually flat, it cannot make it circular again.'' "It's good and it's bad,'' said Mr. Keith Richardson, a local plumber who was observing yesterday's installation. "It saves a lot of time and aggravation, but it also means less work for plumbers like me.'' Overall, though, Insitutube was regarded by the Corporation of Hamilton as the best choice to replace the town's old sewage system, which had threatened to collapse a section of Front Street.

And while the installation of Insitutube has been going on since the middle of January, it has been of little nuisance to merchants, residents or commuters.

This week, another section of the street's sewers -- from just east of Number One Shed to just west of Albuoy's Point -- is to be refitted on Wednesday night.

Photos by Tony Cordeiro PIPE DOWN -- Technicians with the Corporation of Hamilton and Canadian-based Mar-Tech Insituform Ltd. replaced a section of Hamilton's aging sewage system yesterday with the English-designed Insitutube. Above left, the polyurethane tube is lifted from its bed of ice onto a scaffolding, where (above) Mr. Bob Taylor, Mr. Don Swanson and Mr. Clive Hook attach it to the "topstar'' that will lower into the ground. At ground level, Mr. Barry L'Heureux (with cap below) oversees as the tube is pushed by water pressure to its final destination at the foot of Burnaby Street (bottom).