Marine Aggregates

Aggregates Sourced From The Sea

Marine Aggregates
Marine Aggregates

The company's expansion programme has resulted in a supply network which is particularly strong along the South Coast, in London, on the south Wales Coast and in the North-East.

The near continent also represents an important market area with regular deliveries of marine aggregates to Northern France, Belgium and Holland. This capability is built upon CEMEX UK Marine's fleet of sophisticated vessels, which combines capacity and range with flexibility and accessibility.

In addition to supplying the network of wharves with the basic raw material for the construction industry, we have participated in many major civil-engineering contracts for land reclamation and beach replenishment.

Safe Marine Operations

The company and all its vessels operate within the International Safety Management (ISM) Code, the objectives of which are to ensure safety at sea, prevention of human injury or loss of life, and avoidance of damage to the environment, in particular to the marine environment and to property.

In order to fulfil the objectives of the ISM code, CEMEX UK Marine has developed and implemented a safety management system that includes a safety and environmental policy; instructions and procedures to ensure safe operation of ships and protection of the environment; defined levels of authority and lines of communication; procedures for reporting accidents and incidents; procedures to prepare for and respond to emergency situations; and procedures for internal audits and management reviews.

The ISM Code requires effective management of health and safety at sea and this continues to be a crucial part of CEMEX UK Marine's objectives. Work-related injuries and ill-health incidents are preventable and we continually strive to promote and sustain high levels of commitment to occupational injury and ill health prevention, while fostering the development of a positive and effective health and safety culture.

Management works at all levels to ensure that the organisation and arrangements for health and safety are clearly laid down, constantly reviewed and effectively implemented to ensure the health, safety and welfare of all employees, contractors, customers and the general public.

Marine Aggregates


Marine sand and gravel is a natural resource created and deposited, in the main, by fast-flowing rivers in glacial times, in valleys once on dry land, but now submerged by the sea.

The deposits were re-worked during rising sea levels in the warm interglacial stages that followed ice ages, through the action of waves and tides. Fluctuating sea levels over the past two million years have led to the deposition of the sands and gravels that now lie on the seabed. The gravel reserves are essentially immobile and locked in ancient submerged beaches and terrace deposits. In contrast, the sands have been mobile during higher sea levels and have often been formed into banks.

Marine Aggregates


Locating and harnessing the resource to meet our needs is a challenging and complex process. Our marine business ensures the future supply of quality marine aggregates for customers in all its market areas through a managed programme of prospecting designed to secure licences to extract sand and gravel within economical distances of its markets.

This programme uses a range of techniques and equipment, including shallow seismic, side-scan sonar and coring surveys, to locate submerged areas of marine aggregate deposited by rivers and glaciers many thousands of years ago.

CEMEX UK Marine's current licences are distributed in six main areas, including: Humber, East Coast, Thames, South Coast, South West & North West England.

Marine Products

Geologically, marine sand and gravel is similar in terms of origin and mineral composition, as many of the sands and gravels found on land.

The shape, strength and other physical characteristics are generally identical to high-quality land-based aggregates and, as such, the end uses are no different.

After processing at the delivery wharf, products such as 10/20, 4/10 and 0/4 are produced to European standards. Their main use is in the manufacture of concrete, but they are also widely used in other products including asphalt and coated products, masonry and paving blocks, drainage and fill materials.

CEMEX Wharves.


CEMEX UK Marine Limited

Baltic wharf,
Elm Street,
Marine Parade,
SO14 5JF.

Telephone: +44 (0) 23 8072 0200
Fax: +44 (0) 23 8033 4528

Within each region, the location of wharves generally reflects the optimum match between the market they are serving and the location of licenses with suitable resources. If required, transport between regions also takes place.

CEMEX vessels deliver internally to CEMEX wharves and also to external customers and joint ventures. Depending on specific requirements, customers wishing to source CEMEX's marine material can either contact their nearest CEMEX supplier, particularly for processed sand and gravel. Or contact CEMEX UK Marine direct, particularly for large quantities of unprocessed material.

More Information

Mineral Extraction Licences

All aggregate extraction undertaken by CEMEX UK Marine takes place on licensed areas, predominantly in UK waters.

The mineral rights to the sea-bed around the UK are owned by the Crown Estate, which issues licences for extraction. A royalty is paid to the Crown Estate for every tonne dredged and the bulk of revenue is passed to the Exchequer. The Crown Estate will only issue a ‘Production Agreement’ if a Marine Licence is granted by the Marine Management Organisation (MMO) in England, or Natural resources Wales (NRW) in Wales.

Marine aggregate prospecting rights are awarded by the Crown Estate following competitive tender. If a viable deposit is located, then an application to dredge is submitted to the relevant authority accompanied by an Environmental Impact Assessment (EIA). A regulatory decision is reached after consultation with statutory advisers and other bodies such as fishing organisations and local authorities. Marine Licence applications are also advertised in newspapers and comments from the general public are considered at the licence determination stage.

If an application is considered environmentally acceptable then a Marine Licence is granted and a Production Agreement enacted. Marine Licences will include any mitigation and monitoring measures required by the regulatory authorities. Conditions are commonly attached including regular environmental monitoring and zoning to restrict the area dredged at any one time.

To ensure compliance, all vessels working in England and Wales must be equipped with a Crown Estate Electronic Monitoring System (EMS). This records the position and dredging status of the vessel and this data is analysed by the Crown Estate. Positioning of the vessel is achieved by a highly accurate satellite navigation system known as DGPS.


Marine Environment Awareness

Environmental awareness is of considerable and increasing importance, CEMEX, as producers of both land-won and sea-dredged materials are acutely aware of our responsibilities.

Sand and gravel is only taken from licensed areas, with permission to draw materials obtained from the relevant regulatory authority in England or Wales.

Although marine aggregates now represent in excess of 20 per cent of the usage of sand and gravel in England and Wales, dredging licences cover only a small percentage of the UK continental self and an even smaller area is dredged in any year.

In common with planning permission for land-based extraction, the process for gaining a Marine License is both rigorous and extensive. A License will only be granted after wide consultation with relevant agencies, authorities and other sea-bed users and after undertaking a detailed Environmental Impact Assessment (EIA). As part of the EIA, consideration is given to all potentially significant effects, including coastal erosion, fisheries, other marine life, and archaeology.



Marine life

Evidence also suggests that the impact on other marine life is confined to the dredging area and relatively short-lived, with no significant long-term effect on biodiversity. After dredging completion, re-colonisation begins almost immediately and the seabed is biologically similar, typically within 2-5 years, longer in some cases.



Coastal erosion

Coastal erosion driven by waves and currents is a natural phenomenon that affects both beaches and cliffs. Our marine business commissions independent detailed studies before permission to dredge is granted involving careful hydrodynamic analysis. Where necessary, monitoring is performed to ensure acceptable limits are not exceeded and no impacts at the coast occur.




Careful liaison between groups representing local fishermen's interests, scientific organisations and the dredging industry ensures the minimum of disruption occurs. If the proposed dredging licence lies in a sensitive area such as a spawning ground then strict mitigation measures will be imposed or, if mitigation is not possible, consent may be denied.




The preservation of marine heritage and archaeology, namely wrecks and submerged landscapes, are strictly observed by a jointly developed code of practice used by the marine aggregate industry which includes mapping of the seabed prior to dredging to establish the positions of any wrecks and other archaeological features. CEMEX UK Marine adhere to reporting procedures as part of an industry-wide archaeological reporting protocol in partnership with BMAPA and English Heritage.


CEMEX UK Marine, pursue the discharge of their environmental responsibilities with determination. Marine aggregates are fully recyclable and can be reused for other building projects when a structure constructed from them reaches the end of its life. Therefore providing new consents continue to be granted, the activities of responsible companies such as our marine business are designed to ensure that any environmental impacts remain at a minimum, and that the supply of high-quality marine aggregates will be guaranteed for generations to come.