Following the Star Design & Engineering Report

A. Navigation Context — The Voyage Route

Her navigators relied on celestial navigation: measuring the altitude of known stars with a sextant and timing the observation against a marine chronometer, then cross-referencing the Nautical Almanac (first published in 1767; produced by HM Nautical Almanac Office since 1832) to fix their position — the sextant giving latitude, the chronometer giving longitude. The 57 “selected navigational stars” — plus Polaris — were the GPS of their age.

The Voyage: Liverpool to Melbourne

The ship’s primary route from 1852–1875 took her from Liverpool, south past the Cape Verde islands, around the Cape of Good Hope, and across the Indian Ocean to Melbourne — approximately 60 days at sea. The return followed the “clipper route” east through the Roaring Forties, rounding Cape Horn. As the ship crossed from the northern to southern hemisphere, entirely different constellations rose above the horizon:

The Visitor Walk

The dry dock allows a circular walk around the ship, entering mid-ship on the port side. This creates a natural narrative loop: visitors begin at the equator (mid-voyage), walk forward along one side seeing the northern departure sky, round the bow, and return along the opposite side through the southern hemisphere constellations — arriving back where they started having completed the full voyage in stars overhead.

B. Construction & Materials

B.1 Fibre Optic

Two fibre types

The installation uses two types of PMMA fibre optic, each suited to a different role:

• End-glow fibre — transmits light internally with zero side emission. Light exits only at the cut end. Used for all anchor-to-crystal runs and structural bracing lines, delivering light directly into each star crystal without any need for masking. This is the primary fibre type.
• Side-glow fibre — scatters light radially along its length, creating a visible glowing line. May be used for select constellation edge lines where a visible connection between stars is desired. The decision on whether to include side-glow edges will be made during prototyping.

How side-glow fibre works

Standard end-glow fibre optic transmits light internally and emits it only at the far end. Side-glow (side-emitting) fibre is different: micro-scattering particles are deliberately distributed throughout the PMMA (acrylic) core during manufacture, causing light to leak out radially along the fibre’s entire length. The result is a continuously glowing line.

An LED is butt-coupled to one (or both) cut ends of the fibre. Light enters the core and progressively scatters out along the length. Brightness is highest near the LED and tapers with distance — the rate of taper depends on the fibre’s attenuation (typically 0.2–0.5 dB/m for PMMA). Dual-end illumination (an LED at each end) evens out the brightness profile and is our default strategy for runs over ~1.5m.

1.5mm PMMA side-glow fibre (available up to 5mm; exact gauge TBC during prototyping). Shown here lit with a green LED; the same fibre can be lit any colour, and we would likely choose blue for the installation.

Material & specification

PMMA (polymethyl methacrylate) is the standard material for large-core decorative fibre optic. It is lightweight, flexible, easy to cut and polish, and transmits visible light efficiently. Our baseline diameter is 1.5mm — thin enough to be near-invisible when unlit, yet large enough to thread through crystal holes and accept useful amounts of light from a small LED. Thicker fibre (3mm) captures ~4× more light and may be used for long flagship runs; this will be determined during prototyping.

Termination

PMMA fibre cuts cleanly with sharp flush cutters or a dedicated fibre cutter — no specialist cleaving tool is needed. For maximum LED coupling efficiency, the cut end is lightly polished with 400–600 grit wet sandpaper, then seated in a metal ferrule (brass or stainless, 1.5mm or 3mm bore) which aligns it to the LED die. UV-cure optical adhesive bonds the fibre into the ferrule and provides a moisture seal.

End-glow anchor runs — no masking needed

End-glow fibre is used for all engine-to-crystal runs. Because end-glow fibre emits zero light along its length, no masking is required — the fibre is invisible in the dark along its entire routing path, with the cut end delivering light directly into the crystal sandwich.

Side-glow fibre is used only for the short constellation edge segments between adjacent crystals — these glow along their full length by design, forming the visible lines of the constellation pattern.

End-glow fibre

The primary fibre type in the installation is end-glow (end-emitting) PMMA fibre. Unlike side-glow fibre, end-glow fibre has no scattering particles in its core — light travels through the fibre with zero side emission and exits only at the far cut end. This makes it ideal for the engine-to-crystal runs: the fibre is invisible in the dark along its entire routing path, with all light delivered to the crystal.

End-glow PMMA fibre bundle lit from one end — light exits only at the cut tips as bright points, with zero emission along the fibre lengths. Each fibre delivers light from the LED engine to a single star crystal.

Each of the 150 star crystals receives its own dedicated 1.5mm end-glow fibre, routed from the constellation’s twinkle engine along the beam to the mount point, then dropping down to the crystal. The cut fibre end is epoxied into the crystal sandwich, delivering light directly into the crystal body. The same fibre also serves as the structural suspension line — tensioned by a TECNI® TG1.5 gripper at the mount point, it holds the crystal in position.

Material & specification — end-glow

We use 1.5mm bare (unsheathed) PMMA end-glow fibre (Mitsubishi ESKA CK-60 or equivalent) — the same core material and diameter as the side-glow fibre, making both types interchangeable in the gripper and crystal assemblies. The 1.5mm diameter matches the TG1.5 gripper’s cable bore exactly.

Quantity

• 150 crystals × ~5m average run (2–3m beam routing + 2–3m drop) = ~750m end-glow fibre
• Additional structural bracing lines (Delaunay triangulation edges): ~100–150m
• Total end-glow fibre: ~850–900m (order as 10 × 100m reels)

Termination — end-glow

At the crystal end: the fibre is cut flush, lightly polished, and epoxied into the crystal sandwich. The polished cut end is where all light exits — a clean, flat cut maximises the bright point inside the crystal.

At the engine end: all fibres from one constellation are bundled together and inserted into a concentrating ferrule (turned brass, ~8mm bore) that seats in the engine’s 20mm port. The fibres are polished flush with the ferrule face and bonded with UV-cure optical adhesive.

B.2 Star Crystals

Each star is represented by a crystal — glass, acrylic, quartz, or possibly other semi-precious stones — through which the fibre is threaded. The exact crystal material will be determined during prototyping: acrylic offers matched refractive index with the PMMA fibre for smooth optical coupling, while glass and quartz offer stronger refraction and prismatic effects. Crystal sizes are proportional to the star’s actual apparent magnitude (brightness), and crystal colours match the star’s real colour based on its B-V colour index — blue-white for hot O/B-type stars (like Rigel), amber/orange for cool K/M-type stars (like Betelgeuse).

Bristol Blue glass crystals — this vivid cobalt blue could represent blue-white stars such as Rigel, Vega, and Acrux.

Every crystal has its own dedicated end-glow fibre with the polished fibre end terminating inside the crystal, delivering light directly into the crystal body. The fibre is bonded into the crystal with UV-cure optical epoxy, which locks the crystal in position and improves light coupling between the fibre and the crystal.

Off-the-shelf fibre optic crystal fittings

Fibre optic chandelier crystals are an established product category — faceted crystals with pre-drilled apertures designed specifically for optical fibre. These are available off the shelf in a range of sizes and can be used directly as star crystals without custom drilling.

Fibre optic chandelier crystals — an established off-the-shelf component. Right: EP-046 faceted glass fitting (36mm × 30mm, 30g, 3.5mm aperture, accepts fibre up to 3mm diameter).

Large-scale fibre optic chandelier — a single light-colour engine feeds thousands of fibres, each terminating in a different-coloured crystal. The crystals hang directly from the fibres, demonstrating the method at architectural scale. Person on ladder (bottom left) gives a sense of the installation’s size.

Example crystal reference — faceted crystal prisms scattering prismatic light. Final material (glass, acrylic, quartz, or semi-precious stone) TBC after prototyping.

Quartz half-sphere crystals — we have had success sandwiching polished fibre ends inside these, but will explore other stones (moonstone, glass, acrylic) during prototyping.

Fibre-lit crystals (Bleigiessen technique)

Each star crystal is assembled from two crystal hemispheres (or rhinestones, cabochons, or solid gemstones) glued around the fibres at each star position, embedding them securely in the crystal sandwich. Light is delivered from the central twinkle engine via end-glow fibre — the fibre end is cut flush and epoxied into the crystal, allowing light to flow directly into the body of the stone. No electrical wiring or LEDs reach the crystal itself. We have discovered that real gemstones and moonstones are well within the project’s price range — their natural optical effects (adularescence in moonstone, internal reflections in quartz) could produce uniquely beautiful results that synthetic materials cannot replicate, and this will be an exciting area to explore during prototyping. The components inside each crystal:

• 1–3 side-glow fibres (1.5mm PMMA) — visible constellation lines, terminated inside the crystal
• 1+ end-glow fibres (1.5mm PMMA) — delivering light from the twinkle engine; cut end epoxied into the crystal sandwich, light flows into the crystal body
• UV-cure resin — fills the interior, locking all components in position

Cross-section — two solid crystal hemispheres with side-glow fibres (blue) and end-glow fibres (clear) at the equator. No electrical wiring reaches the crystal.

Exploded view — bottom hemisphere (flat face up), components at equator, top hemisphere placed on top.

External precedent — Heatherwick Studio, Bleigiessen (2004):

Thousands of glass crystals on invisible lines forming a floating sculptural volume. The construction technique closely parallels our approach.

Fabrication — crystals laid out on a jig board at precise intervals, similar to our workshop assembly process (see B.8).

A single Bleigiessen glass crystal — dichroic coating produces iridescent colour shifts as the viewing angle changes.

Dichroic film material — self-adhesive film or flakes can be embedded in resin-cast crystals for colour-shifting effects.

Star Colour Science

Star colours are real and measurable — determined by surface temperature and quantified by the B-V colour index (the difference in brightness between blue and visual filters). Based on Charity (2001) and Harre & Heller (2021), “Digital Color Codes of Stars”, the true perceived colours of stars are subtler than popular culture suggests — there are no truly green or deep-red stars. “Red” giants like Betelgeuse actually appear deep orange.

Crystal Material — Tiered Approach

We propose a tiered material strategy that puts the most impressive materials where visitors look closest, and cost-effective materials where they don’t:

Colour × Material Matrix

B.3 Structural Support

Each constellation’s star positions must be held rigid in tension. The structural bracing lines that triangulate the constellation are generated using Delaunay triangulation — a mathematical algorithm that creates the optimal set of triangles from any set of points, ensuring rigidity with minimum lines.

Orion (22 stars) — the most complex constellation of the 88. Blue dotted lines are end-glow fibre (invisible, carrying light to each crystal). Solid blue lines are side-glow fibre (the visible constellation edges). Grey dotted lines are nylon monofilament bracing where additional structural support is needed without a light path.

In the current approach, every structural line is 1.5mm end-glow fibre optic, giving each crystal its own dedicated light supply from the twinkle engine. This eliminates the need for separate bracing lines — the fibre simultaneously provides structure and light delivery. Each crystal sits at a junction where one or more fibre ends are epoxied into the crystal sandwich, with light entering through the cut fibre end.

Nylon monofilament (black fishing line) is used as structural bracing where additional support is needed without a light path. Where bracing lines pass through a TECNI® TG1.5 gripper, the monofilament must be 1.5mm diameter to match the gripper’s cable bore; internal bracing between crystals could be thinner if 1.5mm looks too visible, but this will be assessed during prototyping. Monofilament bonds well with epoxy and is near-invisible in the dark.

We have validated every constellation’s structural stability using a spring-tension simulation: 87 of 88 pass with zero displacement under perturbation, and the remaining one (Circinus) is within 2.2mm tolerance.

TECNI® V-Gliders on 3mm stainless steel cable at the White Storks installation, attached via a Gripple C-Clip. The 1.5 mm Gripple Invisigrip suspension cable (identical in material and dimension to side-glow fibre) was used here for its near-invisibility to support bird wing armatures. The same component family is used in our constellation rigging — substituting threaded M6 grippers for V-Gliders, and adding LED illumination.

B.4 LED Illumination

Each constellation is illuminated by a single 12V DC twinkle engine — a compact 16W RGBW fibre optic illuminator that feeds all the constellation’s end-glow fibres simultaneously. All fibres from a single constellation bundle into a ferrule that faces the LED die. Light travels through the 1.5mm PMMA end-glow fibre, routed along the beam from the engine to each mount point, then dropping down to the crystal. The cut fibre end is epoxied into the crystal sandwich, delivering light directly. There are no LEDs at the anchor mounts or inside the crystals — all light originates at the engine.

With 150 star crystals across 12 constellations, the installation requires 12 twinkle engines (one per constellation). Star colour comes from tinted or coloured crystals, not from LED colour — a single white LED per engine illuminates all stars in the constellation, with the crystal material providing the colour filter.

TECNI® Angled Glider — How It Works

The TECNI® angled glider is the core component that holds each fibre optic line under tension. Its universal pivot joint between the M6 female mounting thread and the gripper body allows the gripper to swing freely and align with the cable direction — essential because constellation lines fan out radially from each anchor, rarely pulling straight down. Understanding the mechanism is important because it determines how the entire rigging system assembles and adjusts.

Inside the gripper body is a cone-shaped bore that narrows towards one end. Sitting inside this cone are three hardened steel ball bearings arranged symmetrically around the cable. When the cable is pulled downward (under load), the balls are drawn into the narrow end of the cone, wedging tighter against the cable — the harder the pull, the stronger the grip. This is a self-locking mechanism: load increases grip force automatically.

To release or adjust the cable, a spring-loaded plunger tube at the top of the gripper is pushed down. This forces the ball bearings back into the wider part of the cone, relieving their grip on the cable and allowing it to slide freely. Release the plunger and the balls re-engage immediately. This gives infinite, tool-free adjustment of cable position — push the plunger, slide the cable, release.

TECNI® TG1.5 Angled Glider (170.015.009) — universal pivot allows the gripper to follow the cable direction.

Technical drawing — 34mm body, 9mm M6 female thread, universal pivot at centre. Same ball-bearing cone mechanism as all TG1.5 variants.

Pot Magnets — Specification

Rubber-coated neodymium pot magnet with M6 external (male) stud. The TECNI® angled glider’s M6 female thread screws directly onto the stud.

The primary anchor magnet is a rubber-coated neodymium pot magnet with M6 external (male) stud. The rubber (TPV) coating protects painted steelwork from scratching, while the M6 stud accepts the angled glider’s female thread directly. Because the actual load per anchor is only ~200g, we can use a compact 32–36mm magnet rather than the larger 66mm size — even 10kg rated pull gives a 50× safety margin. Smaller magnets are cheaper, lighter, and less visible.

Anchor Assembly

A stainless extension spring connects the pot magnet to the TECNI® angled glider, absorbing thermal expansion and vibration. An M6 eye nut screws onto the magnet’s male stud; the spring hooks into this eye and into an M6 eye bolt that threads into the glider’s M6 female bore. The angled joint allows lines to pull at any angle without side-loading the magnet — critical because fibres radiate outward from the anchor, rarely pulling straight down. The anchor assembly comprises four off-the-shelf components:

1. M6 rubber-coated pot magnet (32–36mm, male stud) — attaches to the steel beam (rubber coating protects painted surface, zero marking)
2. M6 eye nut + stainless extension spring + M6 eye bolt — spring tensioner absorbs ~3mm of thermal movement and dock vibration
3. TECNI® angled glider (170.015.009) — screws onto the eye bolt, grips the line passing through it, pivots to accommodate off-axis loads

Every anchor is a fibre anchor: a TG1.5 grips 1.5mm end-glow fibre. The fibre routes along the beam back to the constellation’s twinkle engine, carrying light from the engine down to the crystal at the far end. No LED sits at the anchor itself. Multiple fibres can share a single pot-magnet mount using a gripper stack, keeping the number of physical anchor positions manageable.

Anchor assembly — pot magnet, extension spring (with M6 eye nut and eye bolt), and TECNI® angled glider. 1.5 mm end-glow fibre enters the side exit and exits the plunger nipple. The spring absorbs thermal movement; the angled joint allows off-axis loads.

Exploded view — steel beam, rubber-coated pot magnet (M6 stud), M6 eye nut, stainless extension spring, M6 eye bolt, TECNI angled glider, 1.5 mm end-glow fibre optic.

Rigging process:

1. Place pot magnet on steel beam — rubber coating protects paint, M6 stud points downward
2. Screw M6 eye nut onto magnet stud; hook extension spring into eye nut and eye bolt
3. Screw angled glider onto M6 eye bolt (finger-tight)
4. Thread 1.5mm end-glow fibre through the gripper (push plunger to release, feed fibre, release plunger to lock)
5. Adjust position by pressing the plunger and sliding — infinite adjustment, no tools
6. Clip anchor to longitudinal safety line (secondary retention)
7. Route fibre along beam to the constellation’s twinkle engine, securing with magnetic cable clips every ~0.5m

Alternative Anchor — Eye or Hook Glider for Cable Mounting

Where no suitable flat steel surface is available for a pot magnet — for example, anchoring onto an existing 3mm stainless steel catenary cable or similar infrastructure — the TECNI® TG1.5 Eye Glider (170.015.010) or Hook Glider with latch (170.015.003) provide alternatives. The gripper mechanism is identical (same ball-bearing cone, same 1.5mm cable capacity), but instead of an M6 thread the eye glider has a Ø10mm eye ring (or the hook variant a spring-loaded hook with safety latch). Either connects to a Gripple C-Clip on the support cable via a stainless extension spring (hook ends into the C-Clip bottom slot and the eye ring), absorbing thermal movement and locking the gripper at a fixed position along the cable length.

TECNI® TG1.5 Eye Glider (170.015.010).

Dimensions: 37mm total height, 18mm body width. Ø10mm eye ring, 4mm wire.

The eye glider is the preferred cable-mount option: the closed eye ring cannot accidentally detach, and is the most economical variant. A hook glider with latch (170.015.003) is available as an alternative where faster on-site clip-on/clip-off is needed. Both variants use the same infinite-adjustment gripper mechanism as the M6 threaded version.

Cable anchor assembly — the Gripple® C-Clip clamps onto the 3 mm catenary cable; an extension spring connects the C-Clip to the TECNI® eye glider. Fibre enters the side exit and exits the plunger nipple, routing along the cable to the twinkle engine.

Exploded view — 3 mm catenary cable, Gripple C-Clip (CC3), stainless extension spring, TECNI eye glider (170.015.010), 1.5 mm end-glow fibre optic.

Spring Tensioners

PMMA end-glow fibre has negligible elasticity (~1% elongation at break). Over a typical 3–5 m fibre run, even modest thermal movement of the steel structure (±1–2 mm seasonal, plus vibration from foot traffic and wind) would transmit directly to the crystal and anchor hardware if the fibre path were rigid. A stainless extension spring at every anchor point absorbs this movement, keeping the fibre under gentle tension without risk of fatigue or detachment.

Two configurations are used, matching the two anchor methods:

1. Beam (magnet) anchors: An M6 eye nut screws onto the pot magnet’s male stud. The extension spring hooks into the eye nut at one end and an M6 eye bolt at the other. The eye bolt threads into the angled glider’s M6 female bore. Travel: ~3 mm.
2. Cable anchors: The extension spring hooks directly into the C-Clip bottom slot at one end and the eye glider’s Ø10 mm eye ring at the other — replacing the crimped cable loop used in earlier designs. This is both simpler to install (no ferrule crimping) and adds compliance. Travel: ~3 mm.

The springs are standard stainless steel extension springs (6–8 mm OD, ~25 mm body length, hook ends). At the loads involved (<0.5 kg per fibre), the spring provides a very soft compliance — enough to decouple the fibre from structural movement without adding visible sag.

Twinkle Engine

16W RGBW twinkle engine — CREE LED, ~20mm fibre port, built-in twinkle wheel and driver. 107×95×55mm. RF remote + Bluetooth app control.

A fibre optic twinkle engine (also called a light source, illuminator, or bundle injector) is a self-contained unit that couples LED light into multiple optical fibres simultaneously. These are an established product category — widely used in starfield ceilings, fibre optic chandeliers, pool lighting, and architectural installations. The engine contains everything needed: LED, driver, heatsink, reflector optics, and a fibre port where the cut ends of the fibres face the LED die.

How it works

A 16W CREE RGBW LED is mounted on an aluminium heatsink inside the enclosure. A reflector or TIR lens collects the LED’s wide-angle output and concentrates it onto the fibre port — a circular opening (typically ~20mm diameter) where the polished ends of all the fibres are presented in a tight bundle. Light enters each fibre within its acceptance cone (NA ~0.50, half-angle ~30°) and travels down the core by total internal reflection.

The engine runs on 12V DC from the shared PSU, connected via a 2-pin waterproof plug. A single engine illuminates an entire constellation.

Twinkle effect

Most engines include a twinkle wheel — a slowly rotating disc with irregular cutouts positioned between the LED and the fibre port. As the disc turns, different fibres are intermittently shadowed, causing individual stars to flicker and scintillate realistically. The speed and pattern are adjustable via RF remote. This mechanical effect is simple, reliable, and produces a far more convincing stellar twinkle than electronic PWM dimming of individual LEDs.

Fibre port & bundle geometry

The largest constellation is Orion with 22 stars, so the engine must handle up to 22 fibres. The bundle geometry:

• 22 × 1.5mm fibres = ~38.9mm² total fibre cross-section
• With hexagonal close-packing (~90.7% efficiency), the bundle fits inside a ~7.4mm diameter circle
• Standard engine ports are ~20mm diameter (~314mm² area)
• The fibre bundle occupies ~12% of the port face

We will fabricate a concentrating ferrule — a tapered brass adapter (~20mm at the engine face narrowing to ~8mm at the fibre bundle face) with polished internal surfaces that funnel light onto the small bundle. This could increase per-fibre brightness by 3–5× compared to an open port. We will prototype ferrules using turned brass tube.

Specification

With 12 engines at 16W each, total 12V power is approximately ~192W. Each constellation draws ~21W at 12V (engine + audio module), supplied by its own weatherproof 12V PSU (Mean Well LPV-35-12, 36W capacity).

IP protection & mounting

Almost no fibre optic twinkle engine ships with an IP rating above IP20 (indoor only). The dry dock environment is covered but not climate-sealed — damp patches exist at floor level. Our approach: house each engine inside a standard IP65 ABS enclosure with cable glands for fibre bundle exit and power entry. The compact 16W engine (107×95×55mm) fits comfortably inside. The enclosure sits inside the story plinth (see B.8), keeping it accessible but protected. The fibre bundle exits the top of the plinth and runs up to the constellation, secured along steel beams with magnetic cable clips every ~0.5m.

Fibre Routing — Engine to Crystal

Each end-glow fibre runs: engine → along beam → mount point → drop to crystal. The beam routing section adds significant length, but end-glow fibre transmits zero light along its length, so the routing is invisible even when lit. We use 1.5mm bare (unsheathed) PMMA end-glow fibre — the same diameter as the side-glow fibre, and compatible with the TG1.5 gripper at every mount point.

• Average total fibre per crystal: ~5m (2–3m beam routing + 2–3m drop)
• 150 crystals × 5m = ~750m end-glow fibre
• Magnetic cable clips every ~0.5m along beam routes: ~450 clips
• Side-glow fibre (visible constellation edges): ~70m

Resin Encapsulation

Norland NOA 68 UV optical adhesive — bonds PMMA to glass with matched refractive index. ~48 kg pull-out strength per fibre (10 MPa shear × ~47mm² contact area).

Each crystal sandwich is sealed with UV-stabilised two-part clear epoxy, bonding the cut fibre ends into the crystal halves and providing a moisture seal. The main long-term concern is yellowing. We mitigate this by:

• Using epoxy formulated with HALS (Hindered Amine Light Stabilizers) and UV absorbers
• The dry dock is partially enclosed — not in direct sunlight
• Quick-tack UV resin for positioning during assembly; final structural fill with quality two-part epoxy for long-term clarity

B.5 Mounting & Anchor Points

The dock structure consists of steel beams running perpendicular to the ship, joined by glass beams that drop below the steel. Constellations are mounted using:

• Pot magnet + TECNI® gripper anchor assemblies (see B.4) — fully reversible, rubber coating protects painted steelwork. The RHS beams have no accessible flange, ruling out conventional clamps or straps
• Longitudinal safety line — a thin stainless wire or nylon monofilament running along each beam, linking consecutive anchor points in series. If any magnet pair fails, neighbours catch the load. Satisfies ABTT guidance on secondary retention for items suspended over public areas
• Gripple braided cable + hardware — to extend mounting points from beams or columns to the required position where needed

Gripple C-Clip — Adjustable Catenary Anchors

3mm stainless steel wire rope — breaking load ~756 kg. Used for catenary lines between beams.

Gripple® C-Clip (CC3) — SWL 15 kg. Twist-on/off clamp for creating anchor points anywhere along a catenary wire.

Where anchor points do not fall in exactly the right position, we run a 3mm or 6mm Gripple catenary wire between two fixed points and use Gripple C-Clips to create adjustable anchor positions at any point along the span. The C-Clip is a twist-on/off device that locks solidly onto the catenary wire via internal cams, providing both horizontal and vertical adjustment — it can be repositioned freely before locking, and fitted retrospectively without re-threading the cable.

• Available in 3mm (light-duty) and 6mm (heavy-duty) to match the catenary wire gauge
• One-handed installation, no tools required
• Cams lock solidly in place even at angles up to 60°
• Can be fitted retrospectively — no need to slide on from the cable end
• Independently certified; designed for use with the Gripple catenary system

Gripple C-Clip on 3mm catenary wire — twist-on clamp provides an adjustable anchor point anywhere along the span. Drop cable hangs vertically from the clip.

Gripple Plus — Catenary Wire Anchoring

The catenary wires themselves need anchoring at each end. Where beams or columns are available, the 3mm cable is looped around the beam and the two ends are joined and tensioned using a Gripple Plus Medium connector. A length of flexible hose or rubber sleeving is threaded onto the cable at the contact point to protect the beam’s painted surface from marking — the cable never touches the steel directly.

Gripple Plus Medium joining a 3mm cable looped around a beam. White hose sleeving protects the beam surface from cable contact.

The Gripple Plus is a wire joiner and tensioner in one — both wire ends feed into opposite sides of the body, and internal ceramic cam rollers grip the wire under reverse tension. Tensioning is done with a standard Gripple tensioning tool (10:1 mechanical advantage). The connector is fully reusable — a release key unlocks the cams for repositioning or removal.

Safety factor: We apply a 10× safety factor, consistent with EU entertainment rigging practice. Paint on the steel beams reduces magnetic pull force by approximately 40%. A 32–36mm rubber-coated pot magnet (10–22kg rated) derated by 40% for paint gives ~6–13kg effective pull. Each individual anchor carries only ~30–80g, giving an actual safety factor of 75–430×. Each constellation weighs well under 500g total. With many anchor points per constellation and a longitudinal safety line linking them all, the system is highly redundant even with single magnets.

Anchor Compliance & Safety Notes

The steel beams are rectangular hollow section (RHS) with no accessible flange or gap to pass straps or loops around. This rules out conventional beam clamps, G-clamps, and wrap-around straps. Magnets are the only viable non-invasive, non-marking, fully reversible attachment method for these beams.

1. Magnet as primary retention. With RHS beams offering no alternative clamping surface, the rubber-coated neodymium pot magnets serve as the primary load-bearing attachment. Each anchor point carries approximately 30–80g (~150 fibre anchors across 12 constellations, clustered on shared pot magnets — each constellation well under 500g). Even after 40% derating for paint, a single 32–36mm pot magnet provides ~6–13kg effective pull — a safety factor of approximately 75–430× on the actual load.
2. Longitudinal safety line. A thin stainless steel wire or nylon monofilament runs along the beam, linking consecutive anchor points in series. If any single magnet were to fail, the neighbouring anchors catch the load via the safety line. This provides secondary retention without needing access around the beam. With many anchor points per constellation, the system is inherently redundant.
3. On-site pull-force testing. The pot magnets are consumer/industrial products without independent SWL certification. Before installation, pull-force should be tested on the actual beams using a spring balance or luggage scale — paint thickness and surface condition vary. Document the test results.
4. LOLER 1998 & ABTT guidance. LOLER strictly applies to lifting equipment and lifting operations. Suspending a static lightweight decoration is not a “lifting operation” per se. However, ABTT Technical Standards (“Yellow Book”) recommend secondary retention for all items suspended over public areas regardless of weight. The longitudinal safety line satisfies this requirement.
5. CDM 2015. The installation involves working at height and temporary fixings in a public heritage venue. CDM 2015 applies even to small projects. Responsibilities: Client = SS Great Britain Trust, Designer = Paper Jungle, Contractor = installation crew. A brief CDM notification or awareness note should be agreed with the venue.
6. Risk assessment. A documented risk assessment must cover: magnet failure / dropped anchor during installation, working at height (WAHR 2005), trip hazards from cables and ladders, and exclusion zone below during rigging. The venue may require sight of this before granting access.
7. Periodic inspection. Magnets should be visually inspected at least once per season for signs of coating degradation, corrosion, or reduced holding force (damp environment at floor level could affect beams over time). The safety line and anchor connections should be checked at the same interval.

B.6 Electrical

Each constellation is powered by a single weatherproof 12V PSU that feeds the LED twinkle engine and a compact 12V SD-card audio module with speaker. The mains circuit uses CEEform connectors throughout (IP44, standard stage/site electrics) — no exposed mains sockets, no power bricks, no USB adapters. All connections at constellation level are 12V SELV (Safety Extra Low Voltage), eliminating IP rating concerns for downstream wiring.

Power Budget

Total mains draw: ~296W. At 230V that is ~1.3A — comfortably within a single 13A circuit, with substantial headroom.

Architecture — 12V at Every Constellation

The twinkle engines are 12V DC devices. Rather than plug each engine’s individual mains adapter into an exposed mains socket (which would not be IP-rated), we use a single weatherproof 12V PSU per constellation that powers both the engine and the audio module. This keeps all mains connections inside IP44 CEEform plugs and sockets, with only safe 12V wiring at constellation level.

A key-operated isolation switch at the mains entry point gives venue staff daily on/off and emergency shutdown control.

Mains Distribution

Mains power is taken from the existing electrical outlet at the centre of the stern wall (directly behind the ship) and distributed via a full perimeter loop around the dock, running along the steel beams. All mains-level connections are mounted at beam height, well above the floor.

Full power hierarchy:

• CEEform socket outlet (rear of dock, existing venue supply)
  • CEEform plug (16A blue, single-phase) on mains loop cable
  • Inline portable RCD (30mA) — plugs between venue socket and loop cable, provides residual current protection for the entire installation
  • Key-operated isolation switch (inline) — daily on/off and emergency shutdown for venue staff
  • H07RN-F mains cable (3G1.5mm², heavy-duty rubber flex) — full perimeter loop with CEEform soft Y-splitters at each of 12 constellation positions
  • At each Y-splitter:
    • 12V PSU (IP67, 36W, sealed flying leads) — female CEEform fitted to mains input cable; 12V DC output split to 2× male 2-pin waterproof connectors
    • 12V output 1 → twinkle engine (16W) in IP65 enclosure, via female 2-pin connector
    • 12V output 2 → audio module + speaker (~5W) in IP65 enclosure, via female 2-pin connector
    • All components housed inside the story plinth; fibre bundle exits plinth top and runs up to the constellation

Cable runs are secured along the steel beams using magnetic cable clips, keeping everything tidy and off the floor. Each PSU can be disconnected individually for maintenance without affecting the rest of the installation.

Wiring diagram — top: indicative cable route around the full dock perimeter (orange = 230V mains loop, green = constellation positions). Power inlet at centre of stern wall. Bottom: electrical hierarchy from mains to 12V PSU to LED engine + audio module. All positions subject to site survey.

Cable Hierarchy

Connectors

All connections are tool-free and fully reversible:

• Mains origin: CEEform 16A blue plug into venue socket outlet
• Mains tap-offs: CEEform soft Y-splitters (IP44) at each constellation position
• PSU to devices: 2-pin IP65 waterproof DC connectors (male on PSU output, female on engine + audio box)

Regulatory Compliance Notes

Because the entire mains circuit is assembled from pluggable, pre-made components (CEEform plug, inline RCD, CEEform Y-splitters, IP67 PSUs with sealed flying leads), it is classified as portable appliance assembly rather than a fixed or temporary electrical installation. This significantly simplifies the regulatory position:

1. No BS 7671 installation certificate required. There is no permanent wiring, no junction boxes to terminate, and no cable to strip or connect on site. The system plugs into an existing venue socket outlet via a CEEform plug. BS 7671 applies to the venue’s fixed wiring (their responsibility), not to appliances plugged into it.
2. PAT testing. The assembled mains loop cable (with CEEform Y-splitters and CEEform plug) should be PAT tested (Portable Appliance Testing) before first use and annually thereafter. This is a visual inspection plus earth continuity and insulation resistance test — any competent person with a PAT tester can do this. Each 12V PSU assembly should also be PAT tested.
3. RCD specification. The inline portable RCD must be Type A (minimum), 30mA rated, to detect both AC and pulsating DC earth-fault currents. Type AC is not sufficient where switch-mode PSUs are present. The RCD should comply with BS EN 61008 or BS EN 61009 and be tested (press the test button) before each period of use.
4. Overcurrent protection. The venue’s CEEform socket outlet will be protected by its own MCB on the distribution board (typically 16A for a blue CEEform). At ~1.3A total draw, the installation is well within this rating. No additional MCB is needed.
5. Earthing. The 12V PSUs are Class II (double-insulated), so no protective earth conductor is required at the 12V side. The H07RN-F mains cable carries a CPC throughout; earth continuity is verified as part of PAT testing. The CEEform plug provides the earth bond to the venue’s system.
6. BS 7909 / risk assessment. Although the system is pluggable, it is deployed in a public venue with visiting public. A simple documented risk assessment covering the mains loop routing (trip hazards, cable secured at height, no public access to connectors) is good practice and may be required by the venue. A schematic wiring diagram is provided (see mains_distribution.svg).
7. Mains voltage drop. Preliminary calculation for the distributed load (~1.3A total across 12 tap-off points over ~230m of 1.5mm² cable) gives approximately <1% drop — well within the 5% limit. This should be verified with a multimeter at the furthest Y-splitter once the loop is installed.
8. Emergency switching. The key-operated isolation switch at the mains entry point serves as the emergency switch-off device. It must be clearly labelled, accessible to venue staff without tools, and its location marked on the venue’s fire plan. Unplugging the CEEform plug also provides immediate full isolation.

B.7 Workshop Assembly

Each constellation is pre-assembled in the workshop as a complete tensile unit before being transported to site. The assembly jig is a large mild steel sheet (approx. 1220×2440mm). The process:

1. Project the constellation layout onto the steel sheet
2. Place pucks at each star position — short sections of plastic pipe
3. Place bottom crystal halves into the pucks
4. Position magnetic clamps near each puck
5. Run and tension end-glow fibres from anchor positions to each crystal
6. Assemble crystals — epoxy cut fibre ends into crystal sandwich, apply UV-cure resin, cure
7. Release from jig — the constellation is now a complete tensile unit

Assembly jig — Cassiopeia layout on mild steel sheet. Plastic pipe pucks hold crystal halves at each star position, magnetic clamps tension fibres and bracing lines.

Detail: Schedar (α Cas, mag 2.24) — larger crystal in shorter puck with converging fibres.

Detail: Segin (ε Cas, mag 3.37) — smaller, dimmer star in taller puck.

B.8 Story Plinths

Each constellation is accompanied by a freestanding story plinth on the dock floor below it.

Design

A compact wedge-shaped lectern built from 12mm MDF, painted matt black (sealed and primed before painting). The angled reading surface (~30–40°) is a Perspex top with printed vinyl applied, internally backlit by a small 12V LED strip or puck light. The graphics glow through the vinyl, making the plinth readable in the dark dock environment.

All electrical components inside the plinth are housed in their own IP65 Wiska-style enclosures with cable glands and waterproof connectors, so the MDF body does not need to be IP-rated itself. The plinth contains: the twinkle engine in an IP65 ABS box, the 12V PSU (already IP67), the audio module and speaker in an IP65 box, and the backlight LED. A CEEform 16A inlet on the side connects to the mains loop. The fibre bundle exits the top and runs up to the constellation above.

An internal MDF shelf halfway up provides structural rigidity and separates the electronics compartment below from the backlight cavity above.

Cross-section (side view) — frosted perspex lid lifts off to reveal the equipment shelf. PSU connects to twinkle engine, audio/speaker box, and LED backlight via waterproof 12 V connectors. CEEform 16 A male inlet on the back panel accepts the mains loop cable. Fibre bundle exits through the back wall and routes up to the constellation.

Stability on Cobblestones

Adjustable rubber levelling feet at each corner. Low enough for children and wheelchair users to read comfortably. No wall-mounting — the dock walls are pennant rubble stonework, a Scheduled Monument, and must not be drilled.

Content per Plinth

• Constellation name (large heading)
• Star map diagram showing the constellation pattern
• Named stars with brief descriptions (colour, type, distance)
• Navigation role — how 19th-century sailors used this constellation
• Cultural story — 1–2 sentences from mythology/folklore

B.9 Ambient Sound System

Each constellation’s 12V PSU feeds a compact 12V MP3 decoder/amplifier board with a small speaker, housed inside an IP65 Wiska-style enclosure within the story plinth. Each unit auto-plays the same ambient track from a pre-loaded micro SD card on power-up. No separate cables, no WiFi, no Bluetooth pairing — the audio runs directly from the shared 12V supply alongside the twinkle engine.

Audio Module

Each unit is a 12V MP3 decoder board with built-in class-D amplifier (2×5W) driving a small 40mm 4Ω speaker. The board runs natively on 12V DC — no voltage conversion needed. It accepts a micro SD card (FAT32, up to 32GB) and auto-plays on power-up, remembering its last playback mode (loop all / repeat one) across power cycles. An included IR remote is used once during setup to set volume and loop mode. The board and speaker are assembled inside an IP65 ABS junction box with a circular hole cut in the lid for speaker output, mounted inside the plinth.

Synchronisation

All 12 units are powered from the same mains loop, switched on simultaneously by the shared timer / smart switch. Each board auto-plays on power-up, so all stations begin their track at the same moment. Over time, minor clock drift between modules is imperceptible because the music is ambient and non-rhythmic — gentle pads and textures rather than beats. Any slight phase offset actually enriches the spatial quality, creating a diffuse, immersive sound field as visitors move through the dock.

Volume & Character

Volume is set once per unit using the included IR remote control, keeping levels low enough to sit beneath the dock’s natural soundscape of wind, water, and stone. The result is subtle and atmospheric — visitors notice the music when they pause at a constellation, but it never overwhelms. The ambient, looping nature of the track also makes it suitable for sensory-sensitive visitors.

Content

A single seamless-loop ambient track (2–10 minutes) stored as an MP3 on a micro SD card. The track could be commissioned or sourced royalty-free. Because each SD card is independently loaded, different constellations could carry different tracks in future if desired — just swap the SD card.

C. Detailed Materials by Constellation

Quantities shown are estimates based on the 12 selected constellations. Exact quantities, scale, and spacing will be determined during prototyping.

* End-glow fibre assumes ~5m per crystal (2–3m beam routing + 2–3m drop to crystal). Side-glow lengths are constellation edge segments only. Fibre lengths assume constellations scaled to 0.6–1.8m physical span depending on star count.

D. Detailed Budget Breakdown

All costs are estimates — exact material quantities depend on the final constellation selection, scale, and spacing determined during prototyping. Linked unit costs are verified against UK supplier prices (Feb 2026).

Budget totals £25,000 + VAT exactly. Anchor hardware quantities (~165 grippers, ~70 pot magnets) are estimates — exact mix of pot magnets, hook gliders, and C-clips depends on site conditions, determined during installation. Headroom covers items not yet specified — additional blackout matting, walkway/matting over cobbled areas, and any changes along the way. Note: mains cable length (~230m) is an estimate pending site survey.

E. Rigging & Installation Detail

E.1 Estimated Rigging Time by Constellation

E.2 Access Equipment

A 3-legged aluminium pruning (tripod) ladder is ideal — the dry dock floor is uneven stone, and a tripod ladder is self-supporting on any terrain. This is the same equipment used successfully on our White Storks installation. Height to dock beams is estimated at 3–5m, well within range.

E.3 Installation Sequence

1. Site survey & 3D scan — Measure beam positions, identify power supply locations. Capture a 3D LiDAR scan of the dock structure (iPhone/iPad Pro) to fine-tune constellation placement digitally.
2. Workshop pre-assembly — Thread crystals onto fibre, attach grippers, bundle fibres into ferrules, test each constellation on a jig with engine.
3. Power infrastructure — Run pre-assembled mains cable loop along beams (plug CEEform into venue socket, route H07RN-F along beams with magnetic clips), plug PSUs into CEEform Y-splitters at each constellation position, connect inline RCD and key switch. Plug twinkle engines and audio boxes into PSU 12V outputs.
4. Constellation rigging — Working from simple to complex. Mount connection points, run fibre, tension braces, fine-adjust star positions.
5. Commissioning — Power on, adjust LED brightness, check all crystals are illuminated, install story plinths.

E.4 Tools & General Materials Checklist