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Offshore · Marine construction

Monopile Sea-Fastening Grillages

Saddle grillages that carry a monopile on the deck of a transport or installation vessel: curved saddles on web plates and grillage beams, with liner pads, lashing lugs and stoppers.

Explore the 3D model Send us a drawing
Allmarc 3D model · to scale
Built to your size

Pile diameter, weight and deck layout follow your project.

We have not delivered this product yet. We are equipped to build it: a 30 m bay with 11.5 m under the hook, plate rolling to 40 mm and welding to EN ISO 3834-3. The model shows a typical arrangement.

To your drawing
made
7 m diameter
pile shown
Series
built in
EN ISO 3834-3
welding
Explore the model

How it is built.

Scroll: the camera moves to each part in turn and ends on the exploded view. Drag to turn it round yourself.

Loading model 0%

01 / 07

Holding a monopile at sea

A monopile weighs hundreds of tonnes and rides to site lying on deck. The grillage spreads that weight into the vessel and stops the pile moving in a seaway.

Scroll to see how it is built · drag to turn it round

02 / 07

Saddles and liner pads

Curved saddle plates are rolled to the pile radius. Pads between saddle and pile protect the coating.

How is it possible at Allmarc?
Three-roll pinch cum pyramid plate rolls in the Allmarc works

Used here for: Saddles and liner pads

  • Rolls plate up to 40 mm
All our machinery

03 / 07

Web plates

Web plates carry the load from the saddle down into the beams. They are cut on the laser to the saddle curve.

How is it possible at Allmarc?

Used here for: Web plates

In 2024 we were the only buyer of Deratech’s 20 kW, 12 m laser.

  • 20 kW
  • 12 x 3 m bed
  • Pallet changer
All our machinery

04 / 07

Grillage beams

Beams spread the load over the strong points of the deck. They are built up on our beam line and welded by submerged arc.

How is it possible at Allmarc?

Used here for: Grillage beams

  • Plates matched and tack-welded
  • Automatic feed and stitch welding
  • H and I sections built from plate
All our machinery

Used here for: Grillage beams

  • Full-penetration welds on built-up sections
All our machinery

05 / 07

Lashing lugs and stoppers

Lugs take the lashings and stoppers stand either side of the pile. They are cut from thick plate.

How is it possible at Allmarc?

Used here for: Lashing lugs and stoppers

In 2024 we were the only buyer of Deratech’s 20 kW, 12 m laser.

  • 20 kW
  • 12 x 3 m bed
  • Pallet changer
All our machinery

06 / 07

Made to your drawing

Send the general arrangement or a sketch with sizes and loads. We detail it, fabricate it, trial-assemble it in our bay and pack it for sea. The model is a typical arrangement, not a delivered project.

07 / 07

Every part

Saddles, pads, web plates, beams and lugs.

Why Allmarc

Experience you can trust.

We fabricate to your drawings and prove the fit in our own bay before anything ships. Open any line for the detail.

Talk to an engineer
Heavy rolled plate
  • Leg sections and yoke rings rolled from thick plate.
  • Seams welded on the submerged-arc line.
Round and true
  • Rings braced round while they are welded out.
  • Pin holes cut and checked to jig.
Fitted in the works
  • Yokes, guides and leg sections fitted together before dispatch.
  • A 30 m wide bay with 11.5 m under the hook.
To the designer’s drawings
  • Hydraulics, winches and cranes come from their makers.
  • We build the steel they work in.
Start a project

Have a drawing? Let us build it.

We fabricate to your design, from plate to a packed container. An engineer will tell you honestly how we would build it.

Send us a drawing