Offshore helideck (CAP 437)

Octagonal 1D offshore helideck after CAP 437: extruded aluminium plank deck with perimeter gutter, white perimeter line, yellow TD/PM circle (0.5D inner, 1 m wide), white H (4 × 3 m, crossbar on the obstacle-free sector bisector at +X), black/white OFS chevron, D-value, maximum-mass box and installation name, green perimeter lights at ≤ 3 m, yellow TD/PM circle lights, 1.5 m perimeter safety netting (≈ 9 cm mesh) rising outboard to, but not above, deck level, and a tie-down grid, two access routes (grating link through the net, landing and stair to y = 0 on ±Z), and a steel grillage on four braced CHS legs with knee struts to the cantilevers, base plates and anchor bolts. Leg base plates on y = 0; landing surface at y = height.

Installation

Copies structure/helideck.tsx and the shared lib/ into src/components/deck-twin/. Needs three, @react-three/fiber and @react-three/drei. See installation for the manual route.

Usage

import { Canvas } from '@react-three/fiber'
import { OrbitControls } from '@react-three/drei'
import { Stage } from './components/deck-twin/lib/stage'
import { Helideck } from './components/deck-twin/structure/helideck'

export default function Scene() {
  return (
    <Canvas shadows camera={{ position: [8, 5, 9], fov: 35 }}>
      <Stage>
        <Helideck />
      </Stage>
      <OrbitControls makeDefault />
    </Canvas>
  )
}

Props

P&ID

Plan view: an octagon (or circle) with the touchdown / positioning circle and the letter H at the centre, the D-value and maximum mass written on it, plus the obstacle-free sector chevron.

Layout plan convention (structural / plot plan drawings); CAP 437 markings

The H in a circle on an octagon is unambiguous. The helicopter refuelling package and the windsock are separate items around it.

Helideck design specification (CAP 437) fields and the props they set

D-valuedValue

Deck heightheight

Maximum allowable massmaxMass

Installation nameinstallation

Perimeter nettingnetting

Lightinglights

Typical suppliers

Fabricated to project specification. The geometry is generic and sized from public standards. It is not vendor CAD.

For agents

Machine-readable entry with props, ranges, defaults and ports:

Or fetch /r/helideck.json, or copy a ready-made instruction:

Add the Deck Twin "Offshore helideck (CAP 437)" component to this project. Run `npx -y https://decktwin.com/cli/deck-twin-0.2.2.tgz add helideck` (it copies the file and the shared lib into src/components/deck-twin/), then `npx -y https://decktwin.com/cli/deck-twin-0.2.2.tgz info helideck` for its props, ranges and ports. Render <Helideck /> inside a React Three Fiber <Canvas shadows>, wrapped in <Stage> from src/components/deck-twin/lib/stage. Set props from my data (metres, NPS in inches, ASME class) and leave the rest at defaults. Install three, @react-three/fiber, @react-three/drei and @types/three if they're missing. Full guide: https://decktwin.com/skill/SKILL.md