Slide Rail overcomes difficult ground conditions
Tonn and Blank began the excavation by first cutting a pilot hole on the end nearest to the hospital about 6 feet deep, and laying in a 8 foot tall, 20 foot wide panel.  Eighteen foot long Slide Rail corner posts were then set on both ends of the panel by sliding the posts outside slotted rail down a "t-track" welded on the ends of the panels.  Two more 8 foot panels were installed perpendicular to the first panel, this time by sliding the panels' t-tracks down the corner posts' other set of outside slotted rails which are 90 degrees to the first.

The excavation's ground conditions were unique and challenging as along one side, electrical banks had been recently installed and the soil was almost entirely heavily-saturated fill sand.  Water almost immediately began flowing into the pilot hole and would need to be controlled by pumps while installing the Slide Rail components.  Installing the system was also challenging because the side with sand was very unstable, but directly across the pit was hard-packed clay (next to the loading bay area).  Fortunately, Efficiency's Slide Rail is designed to work in both types of soil conditions, even when both are present on the same excavation project!

After the three panels were set in a "U" shape, foot-printing the first "bay," T & B brought in the first Parallel Beam-Linear Post Assembly and set them on the ends of the open panels.  This cross-trench support is unique to Efficiency's system, and is designed with special parallel beams that pin-in-place standard trench shield spreader pipes.  The parallel beams have rollers which allow them to be removed, creating a completely unobstructed, shored excavation.

To reach 16 feet deep, the panels and posts are pushed incrementally until a depth of 8 feet is accomplished, then more 8 foot tall panels are installed into the posts' inside open-face rails which then are pushed incrementally until the entire first bay is at grade.  The second and third bays are installed in a similar manner as the first.  After the entire system was at grade, level, and stone backfill laid; T & B poured-in-place the tank's concrete foundation.

High praise for Efficiency's Slide Rail System
To assist T & B with the initial Slide Rail installation, Efficiency Production sent on site their Slide Rail Systems Manager, Greg Ross, one of the country's premier Slide Rail installers.  "It's always interesting to see the reaction of contractors the first time they use Slide Rail," explained Ross.  The first day, they usually are intrigued on how and if it's going to work; the second day, there is usually a bit of consternation as they have to overcome unexpected ground conditions as they are trying to put the system in one piece at a time; but by the third day, they really get the hang of it, and they really start to figure out that this is a great system."