Select Bridges
Bridge Building
As bridge building specialists, Select Bridges can manage your bridge project from initial design right through to final installation. We even handle all your consent and certification requirements so you don’t have to!
Designed & Built for you
Select Bridges delivers the best in quality-engineered bridge solutions throughout the North Island. Each project is designed specifically to the needs of the client and the location as well as all legal requirements.
The loadings for the bridge can be specifically designed for the required usage. A standard private bridge has the vehicle loadings of Class 1 (.85HN), which is capable of carrying a 20 tonne truck.
Heavier loadings for large machinery are also possible, as well as for light vehicle loadings or foot traffic. Whatever your bridge building requirements are, we have the solution to suit you.
Site Access
As a minimum Select Bridges require adequate site access for an excavator, to start our work. Whereas, bridges that have concrete beams also require access to one side of the bridge to allow for a crane and trucks to access.
Built to Last
All of our bridges are designed by our consulting engineers with attention to the location as well as the bridge loading requirements.
Under the building act, the structure is required to last 50 years. Our engineers also design Select Bridges bridge construction in reference to the Transit NZ Bridge Building Manual. Therefore, because we follow the design specifications in the Transit NZ Bridge Building Manual our bridges are specified to last for at least 100 years.
Bridges can span from lengths of 6.5m up. The bridge width would depend on your requirements. Typically 4 – 4.2m wide for a single lane bridge.
Bridges vs Culverts
While a bridge might usually be the obvious solution, in some cases, (especially with short spans), the best option is a Culvert.
Why? Because culverts are better able to handle certain flood events making them a more robust and long-term solution.
With our Civil Contracting experience, Select Bridges can also design as well as install Culvert solutions as required.
Bank & Scour Protection
Depending on the situation and integrity of the construction site, it may be advisable to install scour protection on the stream banks prior to installing the bridge.
What are the bank/scour protection options available?
- For example, there is Rip rap rock protection, which consists of large rocks of varying sizes stacked against the river banks under the bridge location to stop the scouring out of the river banks.
- There is also gabion basket retaining/scour protection built under as well as around the bridge location involving gabion rock walls inside wire baskets, built up in 1m high layers.
Select Bridges can provide all these services for you as well as building any retaining, roading and access approaches afterwards.
Don’t like dealing with
Paperwork & Councils?
Building Consents
Additional Consents
New Build
Material Options
There are several options for building construction. The right one for you may depend on the intended use and the bridge loading, as well as your budget and several other factors. We can help determine the best bridge for your site.
Concrete BEAM
Concrete provides durability in all environments and requires no maintenance for the duration of the bridges lifespan.
What are the benefits?
When the concrete abutments, end walls and beams are made off site, the installation is relatively fast, which ensures that the bridge can be used very soon after installation.
What are the limitations?
As the concrete beams are generally heavy, they need to be lifted into place with a crane. With this in mind, good site access to one side of the bridge is required to ensure success of this option.
What is the construction process?
For pre-cast bridges, generally the process starts with excavating out abutment areas as well as placing the concrete components. Following this we would pre-drill pilot holes and drive steel piles through holes in the abutments down into hard ground.
Once the piles have been driven, they are then trimmed down and connected to the abutments.
Beams are brought in and craned into place and the beams are fixed to the abutments. End walls are lifted into place and fixed together. Finally the hand rails are installed on the outside with a concrete curbing in place.
How far can they span?
Concrete beams have a maximum span of 24m. At the longer span double hollowcore beams are used. Double tee beams span up to 16m.
Is there any special requirement that may prevent me from using Concrete Beams?
Most of the concrete bridge beams require a crane to lift them into place and are therefore carted to site on large trucks. Consequently there needs to be adequate access for these vehicles. If this is not possible then steel beams may be a better option.
What is the cost compared to the other options?
At shorter to medium spans, concrete beams, such as double tee bridges, are generally about the same cost as steel beams with a concrete deck.
Steel
Steel bridges can be custom made for any required span or loadings. This might include light loadings such as foot and light vehicle traffic or heavy full highway loadings for large machinery.
What are the benefits of steel?
Steel beams are lighter weight than concrete beams which make transport to site, and lifting the beams in place easier using smaller machinery such as excavators. These are better suited to difficult to access sites. Pre-cast concrete panels can then be made and lifted into place for the decking.
A 20m long x 4m wide steel bridge with concrete decking. As a replacement bridge for several farming properties. Old bridge was washed out. Full highway loading HN-HO-72. Steel beams can span up to 30m with multispan bridges much further.
What are the limitations?
These beams are designed to last at least 100 years but do require re-coating of the paint specifications (depending on paint type and environment) after a given period i.e. 15 – 20 years.
What is the steel bridge construction process?
The construction process for steel beamed bridges is similar to concrete with the foundations. We drive in Piles to suit the ground conditions. We fabricate the beams in Select Bridges yard with cross bracing and plate stiffeners and then grit blast as well as paint to the manufacturer specifications.
How far do they span?
Clear span steel bridges can go up to 30m. For longer spans than 30m, a multi-span would be required.
What is the cost like compared to the other options?
For shorter span bridges, steel beams with concrete decking will cost similar to a bridge with concrete beams. For longer spans, then steel beams and concrete decking will be more cost effective.
Timber
For some sites, where access is challenging, a bridge that is built with fabricated steel beams and timber decking will be the preferred option. Timber decking can be bought in and the deck built on site.
What are the benefits?
The timber will blend in well with nature and therefore be aesthetically pleasing. The timber is treated to ensure longevity.
What are the limitations?
The longevity of the timber decking can be less than concrete. Sites where dairy cows cross regularly, the effluent can be corrosive; this shortens the timbers lifespan making replacement of the decking after a shorter period advisable.
What is the timber bridge construction process?
Generally the foundation can be driven steel piles with a fabricated cross beam on each end for the beams to sit on. The fabricated steel beams are lifted into place and the timber decking then built on site. Finally handrails and curbing are installed which could be either timber or galvanised steel.
How far do they span?
Spans of up to 30m are possible.
What is the cost like compared to the other options?
This option is generally more cost effective than concrete and/or steel, however replacement of the decking will be required due to the lifespan of timber vs. concrete.
“We engaged with Nigel from Select Bridges to design and build a bridge for our Great Barrier Island property in May 2023. Throughout the process Nigel proved his competency and expertise. Construction on an Island has its challenges and logistical complexities but he managed to navigate his way through these and the end result is testament to his professionalism. The work was completed in July 2024. I would recommend Select Bridges as your first choice when considering building a bridge.”
Adrian Thompson, Owner
Existing Bridge
Repairs & Upgrades
Does your bridge require maintenance rather than replacement? Select Bridges can help!
Select Bridges arrange engineering assessment of existing bridges. This includes an investigation regarding its original construction and the provision of recommendations regarding required repair.
Insurance Claims
if your bridge has suffered an event, and has insurance, you may be able to make a claim with the support of a Select Bridges engineering report . This will detail the damage and the extent of repairs required to return the bridge to it’s original status. Select Bridges can arrange this process for you, alongside the provision of estimated prices to complete the repair work.
Emergency Bridging
In situations of failure, we have Emergency Bridge solutions to help during repairs. Available in lengths of 6m and 12m.
BRIDGE DAMAGE, WEAR AND TEAR:
WHAT TO LOOK FOR
Keeping an eye on the the state of your bridge can help you avoid future accidents and costly repairs. Call Select Bridges if you have any concerns about the state of your bridge.
Steel Beams
The steel beams in bridges need to be inspected to determine their overall condition. Oxidation is a visible surface rust that appears like swelling. There may also be pitting of the beams which will decrease their overall strength.
Some beams may require cleaning and re painting, to help reduce the risk of rusting and degradation of the beams. It is certainly not uncommon to require cleaning as well as painting of existing bridges after set periods of time.
Decking
The timber decking on bridges can splinter, crack or rot. This will need monitoring and eventually will need to be replaced.
Foundations
Steel and timber foundations will need monitoring for rotting and rusting as well as cracking. Re-piling of the foundations may subsequently be an option.
Banks
It is not uncommon for banks around the bridge to scour out which can leave the bridge foundations exposed. Ongoing monitoring of bridge banks as well as potential revisiting of scour protection will assist with ensuring the longevity of the bridge.
New & Existing Bridge
Certification
In order to work with certain companies (Fonterra for example) and to comply with insurance requirements, your bridge will need to be certified.
Select Bridges have nationally certified engineers who complete thorough assessments and calculations of bridge structure. A full report on bridges load carrying capacity as well as durability is provided to support ongoing use of existing structures.
This will certainly give you the peace of mind to know your bridge is capable of safely withstanding the loadings it is presently experiencing.
If your bridge hasn’t been designed for it’s present day requirements, or some of it’s components have been degrading to an unsatisfactory state, we can ceratinly provide a solution to upgrade and repair your bridge to ensure it meets it’s current required load bearing limits.
Why You Need our
bridge services
Quality
Versatility
We can meet the requirements of a variety of environments, including sub divisions, farming, forestry, councils, pedestrian and private access.
We do it all
Tailored Solutions
Let's build a bridge
No doubt you have some questions about your bridge project, so get in touch! We’re here to help.
