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  3. Launch & Recovery A-Frames
Offshore · Marine construction

Launch & Recovery A-Frames

A-frames that lift trenchers, ploughs and other seabed vehicles over the side or the stern: box-section legs, cross beam with sheave and snubber, pivot clevises, cylinder brackets and a base skid. Fabricated to your drawings.

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

Safe working load, height and outreach follow your vehicle.

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
8 m
leg shown
Bored in line
pivots
A base skid
supplied on
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 / 08

Over the side and back

An A-frame swings a seabed vehicle from the deck out over the water and lowers it, then brings it back. The structure is ours to fabricate; the winch and hydraulics are supplied by others.

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

02 / 08

Legs

Two box-section legs built up from plate and welded by submerged arc.

How is it possible at Allmarc?

Used here for: Legs

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

Used here for: Legs

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

03 / 08

Cross beam, sheave and snubber

The cross beam carries the lift sheave and a snubber that steadies the vehicle while it hangs in the air.

04 / 08

Pivot clevises

The legs turn on pins in clevises bolted to the skid. The clevises are bored in line after welding, so the 2 pins share one axis.

How is it possible at Allmarc?
SKDX1030 CNC end-face milling in the Allmarc works

Used here for: Pivot clevises

  • Mills beam and column ends square for bolted splices
All our machinery

05 / 08

Cylinder brackets

Brackets on the skid and on each leg take the 2 hydraulic cylinders that swing the frame.

How is it possible at Allmarc?

Used here for: Cylinder brackets

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 / 08

Base skid

The whole system sits on one skid. It goes aboard in a single lift and spreads the load on the deck.

How is it possible at Allmarc?
Kotec newRun10DX CNC beam drilling line in the Allmarc works

Used here for: Base skid

Heavy profiles that need precise holes, where plasma cannot do the job: the lower structure and panel borders of a ground flare, and every bolted PEB and multi-storey frame.

  • H-beams up to 1,000 x 500 mm
  • Drills 3 faces in one pass
  • Channels, angles and box sections
All our machinery

07 / 08

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.

08 / 08

Every part

Legs, cross beam, clevises, brackets and skid.

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.
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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