Asphalt Specialists In Hydraulic Engineering


Coastal Protection
Dam Waterproofing
Dam Erosion Protection
Dam Spillway Protection
Ports & Harbours
Flood Alleviation
River Training
Scour Protection
Underwater Impact Protection
Strengthening Rock Structures
Landfill Linings

Offshore Services

Offshore Services

As a partner of the Marine Mastic Limited consortium, Hesselberg Hydro offers a variety of services to the offshore industry

Marine Mastic Granules

When steel pipelines are concrete coated to give negative buoyancy underwater, the pipe ends are left to allow sections to be welded. On the lay barges, pipes are welded leaving a gap in the concrete. Usually, gaps are filled with hot mastic poured into a shutter placed round the pipe. As welding technology has improved, placing the mastic has become the limiting factor, holding back production.

Historically, mastic was supplied in blocks which were fed into a crusher before heating in the mastic boiler. Hesselberg Hydro's laboratory research and small scale testing of alternative forms of mastic led to a new patented product, Marine Mastic Granules.

Advantages of granules

  • 1-1.5 tonne 'big bags' discharged directly into the boiler reduce manual handling
  • No need for crushing
  • Large surface area to weight ratio reduces heating time

Granule options

  • Industry standard material - D2/S
  • High Temperature mastic – D2/HS
  • Heavy mastic to increase negative buoyancy

Marine Mastic Ltd sold over 40,000 tonnes of granules in its first year. Now, Marine Mastic Granules dominate the market.

Sarmac Mattresses

An ideal protection for cables and pipelines.
In relatively shallow waters, cables and pipelines need protection from mechanical damage:

  • Placements in busy shipping lanes especially vulnerable
  • Protection needed from anchors, rock dumping, and other sources.

And while the world's seabeds are becoming ever-more congested with pipelines and cables, protection of crossing points is a growth area. Sarmac mattresses are often specified for pipeline and cable protection projects

For further information on offshore services, materials and sectors served please visit