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Subsea Structure Frames

Oil & gas · Upstream & offshore

Subsea Structure Frames

Steel frames that sit on the seabed and carry pipeline ends, valves and connectors: tubular frames, mudmats with skirts, hinged protection roofs, guide posts and lifting padeyes, fabricated to the designer’s drawings.

Explore the 3D model Send us a drawing

Allmarc 3D model · to scale

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.

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On the seabed

A frame at a pipeline end, carrying the valve and the connector hub. The designer sets every size; we build the steel.

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

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Frame

A tubular frame welded to a tight dimensional check, so connectors meet first time.

How is it possible at Allmarc?

Used here for: Frame

4 kW
Tubes and sections up to 250 dia
Automatic loading

All our machinery

Used here for: Frame

Qualified welders, including 6G

All our machinery

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Mudmat

A plated mudmat with stiffeners and skirts that spread the load on soft seabed.

How is it possible at Allmarc?

Used here for: Mudmat

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

Protection roof

Hinged, sloped covers that protect the valves from dropped objects and fishing gear.

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Guide posts and padeyes

Posts that guide landing tools, and padeyes for the installation lift.

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Pipework

The client’s piping, valve, hub and ROV panel.

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A kit of parts

Frame, mudmat, roof and posts: every member numbered, match-marked and packed in erection sequence.

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

Structural steel at scale

4 plants at Kanbha; about 6,000 T a month from November 2026.
Plate, sections and built-up members in house.

Trial-assembled

Fit-up proven in the works.
Match-marked for bolt-up on site.

Finished before dispatch

Blast, prime and paint in house; galvanised finishes on request.
Access steel fitted in the works.

Packed for the journey

Export packing we designed ourselves.
Shipped as numbered kits.

Built alongside this

See the full range

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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