When not to use rock bags
Most of this site describes what Texas Tuff Rock Bags do well. This page describes where they are the wrong choice, and what we have not tested. It exists because a specifier who only ever hears the upside has no way to calibrate the rest.
Where bagged armor is the wrong answer
Four conditions where we would steer you elsewhere, or tell you the constraint before you design around us.
The design velocity exceeds the bag's capability
This is the boundary FES states directly. Every size carries a grouped current resistance, and above that rating the unit is the wrong choice — not a marginal one. If your design event puts the velocity past the largest applicable size, bagged armor is not the answer and we will tell you so rather than sell you a course of 8-Tons.
A rigid, monolithic structure is what the design requires
Rock bags work because they are discrete and conformable — they settle with a moving bed instead of fracturing over it. Where the design genuinely needs a rigid mass that will not deform, that flexibility is the wrong property. A grouted or structural solution is the better fit, and the trade-off runs the other way.
You need the supplier to be the engineer of record
FES is a supplier. We do not provide services requiring a P.E. stamp, and we do not produce site-specific designs. If your project needs sealed calculations for the armor, that work belongs to your project engineer. We support them with material data and sizing input; we do not replace them.
The specification demands a certified or listed product
There is no national product standard a rock bag is certified against, and FES does not hold a standing agency approval or a place on a spec list. Requirements are met project by project against the test programme. If your specification requires a named approval we cannot produce, that is a genuine blocker — check it early rather than at submittal.
What we cannot tell you
Data a specifier might reasonably expect, that FES does not have. Each of these is a question we have been asked and answered with "no" — it is more useful to you here than in an email three weeks into a design.
- Published load, pull-out, or stability test results
- None available. In-place strength is documented through ASTM tensile, puncture, and tear testing, but we hold no published stability or pull-out results to hand a reviewer.
- Quantified scour-depth-reduction performance
- No figure we will publish. Grouped bags outperform loose riprap and concrete in the field, but that is a qualitative comparison and we will not attach a percentage to it.
- Citable hydraulic or physical model test reports
- Testing has been done; none of it is in a form we can cite or release yet. When that changes, it will appear on the test data page rather than in a sales conversation.
- Offshore wind installations
- None to date. FES has delivered offshore cable protection work, and that is the experience behind the offshore wind capability page. There is no wind-farm reference to prequalify with.
- Lifecycle-cost or carbon comparison data
- No quantitative analysis exists. Cost advantages we describe are directional and drawn from project experience, not from a costed study. Sustainability claims stay qualitative for the same reason.
Who decides
FES Solutions supplies the product and the material evidence behind it. The design of your project — scour depth, hydraulic loading, foundation conditions, and the governing specification — belongs to a qualified engineer of record. Consult one for site-specific design. Nothing on this site substitutes for that.