Roscoe Bridge

Frequently asked questions

• What is a Roscoe modular vehicle bridge?
• How does the modular-design method save money?
• What is an Abutment?
• How quick can I get a Roscoe Bridge?
• What is the best road surface?
• What is Weathering Steel & Why use it?
• Why use Galvanized Steel decking?
• What load ratings are available?

---

What is a Roscoe modular vehicle bridge?

• The Roscoe vehicle bridge system includes easy, bolt-together modules, nominally 7’,  8’, or 12’ wide, that are pre-engineered for various load ratings and pre-fabricated to rigid AISC quality standards. These modules form the integral units of your bridge, which can be installed in hours, versus days and weeks it takes to build and install a concrete bridge. For more information on the modular bridge concept, see our technical information.

How does the modular-design method save money?

Modular steel bridges can save as much as $1,000 per foot. The following chart shows a savings of $86,000 for an 85-foot Roscoe bridge vs. Concrete bulb tee.

• Standardization of design eliminates high-cost design fees
• Modular design eliminates on-site welding, concrete pouring
  and multiple building trades
• Lightweight steel construction supports single crane/lift capability,
  saving significant cost
• Meets AASHTO specs and minimizes permitting cycle-time and cost
• Single lane bridges up to 75' lengths installed in one day

What is an Abutment?

An abutment is the end foundation (steel, concrete or wood) upon which the bridge superstructure rests. Abutments are engineered several different ways, depending on the site-specific conditions:

• Perched- Abutment installed on level ground that has a pounds per square foot (PSF) soil-bearing capacity capable of carrying the weight of the bridge (dead load) as well as the load-rating of the bridge (live load).
• Piled- The weight of the bridge (dead load) as well as the load-rating of the bridge (live load) is supported by installing/driving steel, concrete or wood piling into the ground, with a "pile cap" typically acting as the abutment /bridge superstructure interface.
• Pre-cast- A concrete abutment, typically integrated with "wing walls" for soil retention, pre-manufactured and transported to the jobsite.
• Poured-in-place- A concrete abutment, with the rebar tied, forms set, and concrete poured at the jobsite.

How quick can I get a Roscoe Bridge?

• First check to see if we have a stock bridge for your application. If we do not have a stock bridge and you have an emergency contact us. We have supplied emergency bridges in 2 weeks. A typical lead time for a bridge delivery to you site is 56 days.

What is the best road surface?

• Roscoe Bridges are designed to support a variety of road surfaces, including gravel, asphalt, timber, and concrete. A gravel-decked bridge is a great value for low-volume traffic like private and rural roads. When required, the additional investment of asphalt or concrete can ensure great service.

What is Weathering Steel & Why use it?

• Weathering Steel is developed for today's environmentally-conscious, maintenance-free bridge applications. There is no painting or coating required for the steel's lifetime. Through metallurgical development and enhancements, engineers have provided a material where the initial rust (oxide) layer actually seals the surface of the metal, preventing further oxidation and rusting. The surface oxides provide a natural patina and blends well in natural settings.
• In cases of graffiti damaging the aesthetics of the bridge, a simple sanding, scraping or blasting of the steel surface is all that is needed to remove the marks. The steel will quickly "re-weather" to the condition it was in prior to the offense. This eliminates environmentally intrusive and costly measures that could harm the stream.
• Weathering Steel has the lowest lifecycle costs of all construction options, including wood, concrete or painted steel.

Why use Galvanized Steel decking?

• Galvanized, roll-formed, steel decking is a very high-quality, high-strength product that provides a service life of 75 to 100 years in well-designed bridge applications. When combined with the addition of gravel or asphalt to provide the primary wear surface for vehicle traffic, the galvanized decking is largely impervious to rusting and abrasive wear. Functionally, the galvanized decking allows the vehicle wheel loads to be distributed to the main support beams.
• Galvanized steel, roll-formed bridge decking has been used as the primary structural support between main bridge beams on new bridge applications as well as bridge rehabilitation projects for over 60 years. The American Association of State Highway and Transportation Officials (AASHTO) sets the standards for bridge design throughout the country and has specified the design parameters appropriate for vehicle and pedestrian bridges, including the design and use of galvanized, roll-formed decking.
• Roscoe Bridge bases our designs for vehicle and trail around the AASHTO Bridge deck specification which includes:
  • Nominal 12" x 4 1/4" dimension with trapezoidal, roll-formed sectional properties.
  • Grade 50 Yield Strength (50ksi), generally the strongest, commercially-available decking in the industry.
• Pre-galvanized bridge decking has a coating weight of 2.00 ounces per square foot of sheet (both sides), per American Society of Testing & Materials (ASTM) and AASHTO specifications.
• The gauge of the decking is a direct function of the load rating of the bridge and is generally either 7 or 9 gauge in thickness.

What load ratings are available?

• Load ratings range from 5 tons (H5) to 102 tons (U102). This covers typical recreational applications with ATV's and light weight vehicles, ranch and fully loaded heavy equipment for logging and mining applications.