When Bridge Inspections Are Needed For Private Bridges
In addition to the over 600,000 highway bridges located across the United States, there are scores of smaller, private bridges that must be inspected and repaired, as well.
While the federal government does not regulate these structures, and the mandates of the National Bridge Inspection Standards (NBIS) do not apply to private bridges, the need remains. And, in fact, there are some states, counties, or other local agencies in various states that may have code requirements that require inspections or certifications.
The particular challenge for these privately built, owned, and maintained roadway bridges is that they are often much smaller than even the smallest public highway bridge. Which means that they cannot be worked on with a typical large truck-mounted platform inspection unit.
In fact, many of these structures can be easily accessed underneath on foot. However, there are others that span gullies, ravines, or swift moving creeks and small rivers.
It’s these structures that must have their under bridge components accessed from the bridge deck.
And that often requires an under bridge access vehicle.
When Smaller Under Bridge Access Equipment is the Right Call
Keep in mind that when we speak here of “smaller” private bridges on private property, we’re referring to those structures that have a bridge deck at least nine feet wide. Anything narrower will not allow for a large truck to be positioned on the deck.
Also, the maximum weight load is a critical concern, as well.
If you were to make use of one of our Aspen Aerials A-30 Bridge Inspection Unit, it’s important to bear in mind that this truck has a minimum weight of over 32,000 pounds.
Load capacity is a crucial factor for any rural bridge as they are often designed to provide access for large farm or ranch trucks with trailers as well as tractors. Full size compact tractors can weigh close to 4,000 pounds, for example, and a large row-crop tractor might weigh as much as 25,000 pounds.
In addition, some private, rural bridges are built on property access roads and designed to handle all types of traffic, including emergency response vehicles, if necessary. This is important since many firetrucks can weigh in at 38,000 to 60,000 pounds.
So, if a private bridge can support a fire engine, then it will manage an Aspen A-30 with no problem!
But a structurally deficient bridge or a load that exceeds a bridge’s support capabilities can lead to a collapse.
[Image courtesy of C. Roberts Consulting Engineers, Inc.]
For example, according to one engineering company, shown in the picture above is a view of a large truck that attempted to back over a private bridge to dump a load of gravel. Immediately, when the rear dual axles of the truck were supported by the bridge, a collapse occurred, trapping the truck on the bridge.
Inspecting Private Bridges on Rural Property: Visual Inspections and the Right Tools
Private bridges are often constructed primarily wood, concrete, or steel. And each material presents its own set of deterioration factors and visual inspection requirements.
For example, visible deterioration of a wood structure can often be easily observed in failing wood members. Issues such as dry rot, vehicle or storm damage, damage from insects, and other decay related deterioration are indicators of the weakening of the structure.
Concrete bridge structures often have an asphalt roadbed overlay on their decks. According to one study,
“One of the most serious problems in maintaining and rehabilitating bridges is the deterioration of the asphalt concrete overlay, and subsequent deterioration of the deck concrete under the overlay.”
The paper went on to note that,
“The results of this investigation found that the deterioration of the concrete of the bridge deck was closely related to the functionality (performance) of the waterproof layer, and the deteriorated depth was significantly related to the average chloride content in the cover concrete of the top rebar.”
Many private, rural bridges are built with steel girders, cross beams, and other steel structural components. And, as the Federal Highway Administration (FHWA) points out, maintaining corrosion protection of steel bridges presents a major challenge to bridge owners.
This is as true for private owners of rural bridges as it is for public entities like state DOTs. As a Kentucky Transportation Center Research Report points out,
‘[S]teel bridge components can crack for a variety of reasons related to design, manufacture, fabrication, construction and service exposure. The latter can include live and dead loading, vehicle impacts and, potentially, wind and thermal loadings.”
In addition, more serious crack problems arise when previously benign cracks grow due to the actions of fatigue, stress corrosion and corrosion fatigue.
All of these issues simply mean that privately owned bridges on rural property should be visually inspected on a regular basis, much like public highway bridges, by either the owners or a contracted engineering firm.
And the use of a suitable under bridge inspection vehicle like an Aspen A-30 unit can be the perfect platform for conducting those inspections.
Under Bridge Platforms: When You Need the Best in Bridge Access Equipment
Under bridge access is an ongoing need for property owners or private contractors specializing in bridge work, for inspecting, maintaining, and repairing privately-owned bridges. And that means that having reliable under bridge access is also a regular part of your line of work.
The good news is that Pro Crane is the professional firm that you can rely on to provide you with and guide you through the process of buying or renting, the right under bridge inspection vehicle and under bridge platform equipment you need for your next project.
At Pro Crane we make it our mission to always help you make the right choice.
Our is made up of several different under bridge inspection platform vehicles, all of which feature multiple capabilities. And along with price and reach capabilities, the structure and the terrain of your project are also key factors for determining the best choice for your work.
Pro Crane provides quality under bridge platforms throughout all the Western United States, including Utah, California, Nevada, Washington, and Oregon.
Our large and expanding inventory of articulated boom lift trucks and under bridge platform vehicles features several high-quality and high-capacity pieces of equipment. In addition to the mighty Aspen Aerials A-30 bridge inspection unit, these include the impressive Aspen Aerials A-40 Bridge Inspection Unit, the versatile HPT 38 Truck-Mounted Platform, and the Bridgemaster-Art-B-4 Bridge Inspection Unit.
And we are proud to be the only California-based company that offers total under bridge access.
In addition, as a result of our consistent high quality customer service, we have built and fostered long-lasting relationships with our esteemed customers. And we always work hard to keep it that way.
Contact us today to discuss the specific needs for your project.
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