Armour Rock & Boulders

Graded armour rock and boulders for breakwaters, in Supramax lots and on deck barges

Armour rock under HS 2516.90 and 2517.10 is the heavy end of the quarry trade: rock blasted and sorted, not crushed, and bought by weight class rather than by sieve. A breakwater or revetment design (CIRIA Rock Manual, EN 13383) calls for a primary armour layer of, say, 3–6 t or 6–10 t, an underlayer of 300–1,000 kg or 1–3 t, a filter layer of 60–300 kg and a core of 1–500 kg quarry run, each with a specified weight distribution (W50, and limits on the fraction lighter and heavier than the class), and a contractor is paid on the tonnes placed in each layer. The stone has to be sound and dense. Granite, gabbro and basalt at ≥ 2.6–2.9 t/m³ give the mass per block the designer assumed; water absorption ≤ 1–2% and a magnesium sulphate soundness loss ≤ 12% (or freeze-thaw where the climate demands it) say the block will not split in service; LA abrasion ≤ 25–30% and a point-load or unconfined compressive strength above 100 MPa say it will survive handling, and blockiness and a length-to-thickness ratio under 3 keep the placement interlocking. Chloride and sulphate are checked when the rock sits against reinforced structures, and a visual check for open fissures and clay seams is done at the quarry face, not the discharge berth.

The freight is the deal. UN Comtrade, 2025 export declarations: Oman exported 12.02 million MT of HS 2517 at USD 6/MT FOB, Indonesia 9.20 million MT at USD 7, Malaysia 5.90 million MT at USD 9 and Canada 9.24 million MT at USD 17; under HS 2516 (granite and other monumental or building stone, which includes rough blocks as well as boulders) India declared 9.29 million MT at USD 60/MT and Brazil 0.82 million MT. Quarry-gate armour rock sits between those numbers, USD 8–25/MT depending on class and origin, and a Supramax voyage from Fujairah, Sohar, Andhra Pradesh or Tamil Nadu to the Maldives, Bangladesh or the Gulf costs more per tonne than the rock does, which is why we do not quote FOB alone. The stone is loaded by excavator, grab or wheel loader into Handysize and Supramax holds (boulders over 1 t need dunnage and a stowage plan the master will accept) or onto flat-top deck barges for short lanes and for discharge over a beach or an unfinished breakwater with no berth; deck barges also allow direct placement by excavator where the design permits. CBIL is a commodity brokerage company that also runs a chartering desk (LaycanDesk), and we price the rock with the vessel: Omani and Indian boulder stems into the Bay of Bengal and the Coast Connect enquiries we are working now are quoted CFR or CIF with the ship named, laytime matched to the quarry's loading rate and the discharge method agreed with the contractor. Send your weight classes and tonnes per layer, the design standard, the density and absorption limits, the discharge point and whether it has a berth, and we match quarry and tonnage against them.

Need the ship as well? Our chartering desk prices bulk limestone, gypsum and aggregates freight on LaycanDesk.