A state DOT, county, or public utility buys from standard specifications. Materials are drawn from an approved products list or qualified products list, and the specification tells the contractor what to supply and the inspector what to accept.
That system exists for good reasons: consistency, quality control, and removing per-project argument about materials.
It also means a product outside the list faces an obstacle that has nothing to do with whether it works.
The obstacle is structural, not technical
A specification writer working from a standard document has categories for riprap, for concrete, for gabions, for the systems the document contemplates. A system the document does not contemplate is not rejected. It is unaddressed, and unaddressed is functionally the same as unavailable to someone who has to write a biddable specification by Friday.
Recognising that changes what you do about it. Arguing performance to someone whose problem is procedural does not help them. Giving them a defensible route to include it does.
The three routes
1. Specify by performance, not by product
Write the specification around what the armor must achieve — the design condition, the required stability, the service life, the documentation to be provided — rather than naming a material.
Advantages: it is competitively neutral, it survives procurement scrutiny, and it lets any system that meets the requirement compete.
The catch is that the performance criteria have to be genuinely writable and verifiable. Where we can support that, we can; where our own data does not establish a value, we say so rather than supplying a number to fill a blank. When not to use rock bags is a list of exactly those gaps, and a specifier is better off knowing them.
2. Equivalency or substitution
Many agencies have a process for approving an alternative as equivalent to a specified material. The contractor or supplier submits a case, the agency’s materials or design office reviews it, and it is approved for the project or generally.
This is usually the most realistic route for a first project with an agency, because it is a defined process with a defined owner.
3. Get on the list
The longer play: apply for inclusion on the approved or qualified products list. Requirements vary and typically include documentation, test data, and often installation history within the state.
Slow, and it is the route that makes every subsequent project easy. Worth starting even if it will not help the job in front of you.
What a reviewer actually needs
Speaking plainly about our own position, because it shapes what we can supply.
What we provide:
- Which test method backs which claim, and which laboratory ran it. ASTM and ISO tensile, puncture, and tear; EN 12447 hydrolysis; EN 12224 weathering; BS EN ISO 13438 oxidation. See test data and standards
- Product dimensions and rated conditions — specifications and spec sheets
- A published statement of limitations — when not to use rock bags
- Sizing method and design basis — design and sizing
- Named project experience where the client has cleared it for publication
What we do not provide, and will not invent:
- Measured test values. We publish methods, not numbers. This is a deliberate policy, and the reason is that a plausible-looking figure on a page a DOT reviewer relies on is an invented figure.
- Certifications. We hold none, and we do not describe ourselves as certified.
- A P.E. stamp. FES provides no service requiring one. We are a supplier, not the engineer of record.
- Physical model test results for conditions we have not tested.
Some reviewers will find that combination sufficient and some will not. A reviewer who needs a measured tensile value to complete their evaluation is a reviewer we cannot satisfy today, and it is better for everyone that they learn it in week one rather than week twelve.
What tends to help
Start before the specification is written. Once a document naming a material is out for bid, changing it is a procurement problem. Talking to the design office at concept stage is a design conversation.
Talk to the right office. Design, materials, and construction have different concerns. The materials office usually owns product approval.
Bring the limitations first. Leading with what a product does not do is unusual enough to be credible, and a reviewer’s job is to find the gaps. Handing them over saves everyone a round.
Anchor to what they already accept. Explaining a system relative to an approved one — how it differs in failure mode, installation, and maintenance — is more useful than describing it in isolation. The comparison hub is written for that, including when riprap is still the right choice.
Name a case where you are the wrong answer. A supplier who says their product does not suit certain conditions is easier to believe about the conditions it does suit.
Offer a constrained first use. A defined, low-consequence, well-monitored application is an easier approval than a headline structure, and it generates the in-state history the list route needs.
The emergency route, and its trap
Emergency work sometimes gets material approved quickly under emergency provisions. That can be a genuine opening.
The trap is assuming the emergency approval carries forward. It usually does not. Approval for emergency use on one job is not general approval, and converting one into the other means going through the normal process anyway. Start that process while the relationship is warm.
Where to go next
- Permitting in-water erosion work for the regulatory side
- What an agency reviewer wants to see
- Assembling the submittal package
- Cost, procurement, and specification for writing a spec that does not lock out a system
- DOT and municipal for the sector
- The permitting hub for the rest