St. Francis Hospital in Indianapolis, Indiana, is in the midst of a $265 million expansion. When completed by mid-year 2010, the Indianapolis hospital campus will have a new emergency room, six-story inpatient tower, surgical suites, and additional space for support services.

As part of this huge expansion, Tonn and Blank (T & B) Construction Company headquartered in Michigan City, Indiana, (The construction subsidiary of the Sisters of St. Francis Health Services, Inc.) is installing a 30,000 gallon fiberglass fuel tank measuring 47 feet long, and 12 feet in diameter. The tank will be used to fuel the hospital’s backup generators.

On a busy hospital campus such as St. Francis, a project such as this was not going to be easy or routine. The excavation site was located about 6 feet from the hospital, and had very limited access and many surrounding obstacles to contend with, including: a loading bay dock directly along one side that had to stay open throughout the excavating and installation process, and newly installed electrical banks just a few feet on the other side of the excavation site. Excavators and other equipment could only access the site from two sides.

Shoring the excavation to T & B’s strict safety standards was going to be a huge challenge.

United Rentals Trench Safety Answers Call, Provides Solution
Tonn and Blank Foreman Stan Burnside contacted Jim Wright, Branch Manager at United Rentals Trench Safety in Indianapolis, to discuss shoring. “After looking at the specs of the project, I could see that our options were very limited,” said Wright. “I contacted Scott Moreland, United Rental Trench Safety’s Product Install and Shoring Specialist, to discuss all of our options.

“Vibration restrictions at the hospital eliminated the option of using vibratory-hammer installed sheeting and bracing,” continued Wright. “Also, installing a beam and plate or lagging system was off the table due to the two week schedule given to complete the project. When it was all said and done, a Slide Rail Shoring System really was the best option for the tank installation; it was the most cost effective system for the job,” Wright concluded.

After designing a slide rail shoring plan, Wright and Moreland called Efficiency Production in Mason, Michigan–a leading manufacturer and engineering specialist of Slide Rail Systems–for proposal drawings for a three bay, 4-sided Multi-Bay™ Slide Rail System that would allow T & B to completely shore an unobstructed pit 56 feet long, 16 feet wide on the ends, down to a depth of 16 feet.

Efficiency’s unique Parallel Beam cross-trench design fits in tight spot
Efficiency’s Universal Slide Rail is a component shoring system comprised of steel panels (similar to trench shield sidewalls) and vertical steel posts. The versatile system can be used in a variety of configurations, such as small four-sided pits; large unobstructed working pits as big as 50 x 50 feet with Efficiency’s ClearSpan™ System; or in a linear Multi-Bay™ configuration to install length of pipe over 40 feet. For T & B’s tank installation project, an unobstructed opening of more than 55 feet was made possible utilizing Efficiency’s unique Parallel Beam cross-trench support design incorporating external ClearSpan™ waler I-beams.

“When Jim (Wright) first suggested Slide Rail, I was a bit skeptical, because I wasn’t at all familiar with it, and it didn’t sound anything like other shoring systems I’ve used,” said Burnside. “But, Jim did a great job explaining to me what it is, its advantages, and how it works.”

Slide Rail safest choice for strict requirements
Tonn and Blank has an exceptional safety record for all their construction projects and Slide Rail was a perfect fit for their strict requirements. Slide Rail is installed simultaneously as the trench or pit is excavated by sliding the panels into integrated rails on the posts–either double or triple rails depending on needed depth–then pushing the panels and posts incrementally down to grade as the pit is dug; a process commonly referred to as a “dig and push” system. Slide Rail is unique in that it is installed and removed incrementally, which allows the trench to be properly shored and safe for workers to be in the excavation throughout the entire installation or removal process.

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.”

Tonn & Blank’s Burnside concurred: “There is definitely a learning curve the first time you use (Slide Rail), but once you get the hang of it, it goes in very easily and quickly,” he said. “Having Greg (Ross) here for a few days really helped in getting the system started going in the ground correctly, and helped get my crew into the swing on how to install it.”

After the ClearSpan™ waler beams were secured in the integrated brackets that slide down the outside face of the linear posts; the three parallel beam-spreader assemblies were removed for the tank set. The result was an unobstructed pit that was 56 feet long and was able to accommodate the 47 foot long tank. The tank was set with a crane and backfilled with stone, while the slide rail components were pulled incrementally from the ground as the backfill progressed.

“(The Slide Rail System) really met my expectation,” concluded Burnside. “As we were taking the system out of the ground, I thought to myself that I can use this (system) on another excavation project coming up in a few months. In fact, I wish I knew about this earlier, because it would have worked great on some other utility projects here at the hospital that we’d already completed.”

United Rentals Trench Safety-Multiple Solutions for Multiple Applications
Since opening the branch in 2005, United Rentals Trench Safety of Indiana has worked with contractors on many engineered trench safety systems throughout Indiana and Northern Kentucky. The Indianapolis branch has done multiple installations with Efficiency’s Slide Rail System in 4-Sided Pit, Multi-Bay™, and ClearSpan™ configurations. In each instance, the system has saved the contractor both time and money.

United Rentals - Trench Safety is North America’s leading trench shoring services company, providing safety systems to protect construction workers below ground. A complete line of shoring and trench shielding equipment, pipe testing equipment, gas monitors, pipe lasers, and “Trench Safety Plans” designed by a Registered Professional Engineer for complex trench excavations. are available through United Rentals’ Indianapolis Branch. Contact United Rentals Trench Safety in Indianapolis at 317-375-1483.

Tonn and Blank Construction is dedicated to quality, diversity, and flexibility. By streamlining services and maximizing resources, T & B’s experience through the years has earned them a solid reputation for fulfilling needs as a General Contractor, Construction Manager, and Design/Build Team.

Efficiency Production, Inc., “America’s Trench Box Builder™,” provides the widest selection of standard and custom trench shielding and shoring systems. Efficiency’s versatile products are designed specifically for safe and cost effective installation of utility systems and infrastructure improvements. All products are P.E. certified to meet OSHA and MIOSHA standards.

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The excavation site had very limited access and many surrounding obstacles to contend with, including: a loading bay dock directly along one side and newly installed electrical banks just a few feet on the other side of the excavation.	For T & B’s tank installation project, an unobstructed opening of more than 55 feet was made possible utilizing Efficiency’s unique Parallel Beam cross-trench support design.
After the ClearSpan™ waler beams were secured in the integrated brackets that slide down the outside face of the linear posts; the three parallel beam-spreader assemblies were removed for the tank set. The result was an unobstructed pit that was 56 feet long and was able to accommodate the 47 foot long tank.	The tank was set with a crane and backfilled with stone, while the slide rail components were pulled incrementally from the ground as the backfill progressed.
Branch Manager of United Rentals Trench Safety in Indianapolis, discusses the installation of the Slide Rail System with Tonn & Blank’s Foreman, Stan Burnside (right)	Greg Ross (center), Efficiency’s Director of Slide Rail Systems, instructs Tonn & Blank’s Excavator Operator (left), and Foreman, Stan Burnside (right), on how to properly install the Slide Rail Components.