Are you looking for the Right Precast Concrete Pontoon and Buoy Supplier ? The sole purpose of a pontoon or buoy is to float, hold its position, and do so through storms, tides, and years of saltwater without anybody wondering why. If it works then nobody will know. If it doesn’t work, the problem is most often not the product of the structure, but rather the product of the supplier behind it. This guide explains how to review a precast concrete pontoon and buoy supplier to ensure that you don’t end up in the second category, but the first.
Choosing a Supplier Depends More on Their Choice of Products than the Product Spec Sheet
The first place most buyers begin their search is by checking out the dimensions, buoyancy ratings and price per unit. It’s a good beginning, but it doesn’t cover the key issue of how the supplier constructs, strengthens, and finishes the concrete to withstand the service life.
The sea can be a harsh place. Wave loading, wave wetting, wave drying and wave loading by waves or waves and wakes of the water especially harden concrete as compared to onshore applications. A supplier who considers marine precast a specialized area rather than “concrete that floats” will consider these stresses from the start of the design process. If one refuses, he will give you a unit that appears to be as good as new when it’s delivered, but begins to spall or lose buoyancy after a few seasons.
Make Sure You Are Ordering What You Want!
To begin making supplier comparisons, it is helpful to know what product your project requires, as not all precast marine manufacturers offer the entire spectrum of products.
Floating Pontoons
Floating pontoons are floating platforms that carry a load.Floating platforms that have a load are called floating pontoons. They must have sealed chambers of air or foam-filled cores for flotation and a sufficient amount of structural integrity to not flex under loads applied by pedestrians, vehicles or equipment.
Mooring Buoys
Mooring Buoys are anchored floats which are employed to moor ships without using a fixed mooring berth. They require a combination of buoyancy, fatigue resistance of the chain to the attachment and a hull form that will not roll in the waves.
They Will Also Cover the Use of Navigation and Marker Buoys
Navigation and marker buoys do not carry load and are used to show channels, hazards or boundaries. The anchoring system’s visibility, colour-fastness and stability are more important than its structural capacity.
Precast Marine Anchor Blocks and Sinkers
Buoys and pontoons have ballast units (precast marine anchor blocks or sinkers) that help maintain their position. Although these are just plain mass units, they must still incorporate the attributes of the seabed, chain or shackle attachment and resistance to abrasion.
Having established which category — or combination — your project requires, you can now begin to filter the list of suppliers to manufacturers that specialize in this category, instead of those that offer it as an additional precast product to their land-based line.
Inquire About Their Marine Concrete Mix Design
A precast concrete supplier that is serious about applying concrete in marine applications should be using a mix design developed for submerged or splash-zone service, not their regular standard structural mix to which a waterproofing additive has been added. This usually involves low water-cement ratios, sulphate resisting or marine grade cement and a greater cover of reinforcement to protect against chloride induced corrosion.
Specifically enquire about the exposure class the mix is intended for, cover for reinforcement and non-corrosive reinforcement like galvanized or epoxy coated steel or fibre reinforcement, in critical units. Any supplier that responds with numbers is communicating in your language. Anybody who claims to use “good quality concrete” deserves a second look.
Examine How They Handle Buoyancy and Sealing
The single most important detail, and the easiest one to get wrong is the sealing and buoyancy chamber design, for anything that needs to float. Inquire about how flotation chambers are sealed, if they have redundant chambers, if a single one fails the unit won’t sink, and how they test for buoyancy prior to the unit entering the yard.
Some suppliers stress test or water test each of their units prior to sending them out. Some others depend on the mould geometry and have faith in the process. Either can be effective, but you can’t have a case of “it floats fine” when you’re in need of a definitive answer with regard to testing.
Review Their Manufacturing Quality Control
The quality of the concrete is a big variation among different manufacturers, even if two pontoons are the same on the spec sheet. Investigate how units are cast (wet or dry), the curing process involved, and the quality checks conducted before a unit ships.
As it would seem, surface finish is more significant with marine work. A well-cured, dense finish will hold up much better against marine growth and abrasion than a porous finish, and an edge and corner detail will not chip during transport, craning or installation like a porous finish. These details will give you a lot of information on how much care a supplier practices in her manufacturing line.
Ask for Engineer’s Drawings and Mooring Calculations
A good supplier will give you the appropriate engineered drawings for your particular installation, not an “off-the-shelf” catalogue sheet. For buoys and pontoons that should include buoyancy calculations, expected freeboard when fully loaded and mooring or anchoring loads when considering the water depth, current and wave exposure at your site.
Suppliers that can provide this degree of engineering assistance can identify site-specific problems, such as tidal range, seabed type, vessel traffic, etc., prior to installation, not after they don’t feel right in the water. Where a supplier is unable to supply project-specific calculations, you are likely to be purchasing a standard unit which has been designed for different conditions.
Compare the Installation and Mooring Requirements
The installation needs for pontoon and buoy systems vary greatly. There are flexible modular joints for some pontoons that require very little site work, while others may require a piled or anchored mooring system specific to the site. Buoys must have an anchoring system, such as chain, wire rope or synthetic line, that is suitable for the sea bed and anticipated loads.
Request your supplier to tell you what mooring hardware they require or supply, if they have instructions as to installation, and if they have installers or contractors who have experience with their product. If your team thought the system was going to be drop-and-moor, but it requires specific anchor blocks, you’re in for a hefty bill of delay.
Look into Their References and Track Record
Design standards and mix specifications indicate what a supplier can do. Fully built projects provide you with what they’ve actually delivered. Please provide examples of pontoons or buoys that you’ve supplied to projects in similar water conditions (similar water body, exposure, loading) and photos of them, taken after they’ve been in place long after delivery, not the day they were installed.
Note how these units have been performing over time. A level, sound pontoon after a few years in the ocean and weather, is a testament to a supplier’s quality more than any brochure.
These Red Flags are Indicators That Should Be Monitored
Some warning signs appear again and again when distinguishing the reliable marine precast suppliers from the others: answers that are not unequivocal when asked about mix design or exposure class, unwillingness to give project specific buoyancy or mooring calculations, no clear testing process for sealed flotation units, and pricing that is clearly lower than the other suppliers with no explanation why.
Individually do not exclude any supplier, but two or three of these together should merit more questions and investigation for commitment.
Integrating All of the Above!
The key is in selecting the right precast concrete pontoon and buoy supplier by understanding exactly what you need, and by understanding that the supplier has a design that is intended for marine exposure with the right mix design and cover, understands buoyancy and sealing before the product is dispatched in the water and is backed by real engineering experience and a proven history in the water, and not just on paper. That’s a risk of building something that’s supposed to remain afloat and on station for years. Do it right, and your pontoon or buoy does what it’s supposed to: sits quietly on the water doing its job, no one knows it’s there.
