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

Marine Mastic
Sarmac Mattresses

OSA Mattresses

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

A new world record!

Over 6 km of large diameter pipeline placed in 24 hours
with an improved mastic supply

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. H

istorically, 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 joint patent with Bitumarin bv., for a Marine Mastic Granules production process.

Advantages of granules

  • 1 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

Bespoke alternatives to the main grade 'industry standard' granules include

  • Heavy mastic to increase negative buoyancy
  • High Temperature Mastic for 'hot lines'

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

And pressure is back on the welding technologists to increase their speed!

Sarmac Mattresses

An ideal protection for cables and pipelines in shallow waters

Manufactured by Marine Mastic Ltd in England, Scotland, Holland and Norway
To serve the North Sea

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.