Projection dome

Client:  Charleville Cosmos Centre

Projection: Immersaview

Build: 2018

Description:  A 15 metre diameter hemisphere dome with durable cover built on top of a 4.2 metre wall


Charleville is 750 kms west of Brisbane, and so is very hot in summer.

We built the dome in January and temperatures were over 40 degrees.

The dome needed to be placed (and held down) on top of a 4.2 metre high circular wall


The dome (with cover on) was built on the ground next to the ready-built wall.  A 15 tonne slew was hired to lift the completed dome onto the wall.

Dyna bolts combined with ChemSet were drilled into the top of the concrete wall attached to L shaped brackets connected at the 30 base nodes of the dome frame.  The dome canopy was made with 850 gsm Mehler pvc having a 20 year warranty suitable for the extreme weather conditions.

A 150mm ‘apron’ at the bottom of the canopy was designed to overlap the sides of the circular wall.  It was attached and sealed to create an airtight finish.


Setup and execution

When the dome was being built at ground level, 5 nylon cords were looped through ring nuts on the top pentagon.  Once the dome was bolted down on top of the wall, the lightweight internal projection screen was tied to the chords and hauled up to almost the top of the dome.  A custom made timber boxed-in pelmet was built on the inside top of the wall (with hook velcro connected).  The loop velcro on the outside of the projection screen was attached to the hook velcro on wall, and 2 extractor fans sucked out the air between the two skins to create a negative pressure (vacuum) and thereby ‘inflate’ the screen.  These fans have a voltage regulator and have been in action 24/7 since the dome was built in 2018.

Installation of tiered seating was done by local contractors, and the projectors and media server were provided by Immersaview, Brisbane.


Outcome and benefits

The projection screen is hemisphere with a surface area of 360 square metres.  The sophisticated media server does mapping of planetarium content or fulldome movies.

2 of the featured 30 minute movies are “Oasis in Space” and “Our Living Star”