Bracing Structure of HMVS Cerberus

Geotechnical Study

The 2003 Geotechnical Study carried out by G.H.D. and funded by Heritage Victoria, Parks Victoria and the City of Bayside, concluded that "catastrophic collapse is imminent". The most likely scenario is that the weight of the gun turrets will become too much for the deteriorating supports and that each turret will then collapse through the breastwork, possibly precipitating the collapse of the breastwork.

Removal of Guns

As an interim measure Friends of the Cerberus applied for and received an $80,000 grant from the Heritage Council of Victoria in October 2004. This grant, announced by the Victorian Minister for Planning, enabled the four 10 inch guns to be removed from the ship. Weighing a total of 73 tonnes, it was hoped that the reduced weight of the gun turrets would delay the inevitable collapse long enough for stabilisation to be funded.

Minister Delahunty after announcing the grant.

Removing the first gun in March 2005.

Bracing the Turrets

In 2008 Friends of the Cerberus applied for and received a grant of $500,000 from the Federal Government to assist in stabilising Cerberus. The National Trust generously agreed to hold the funds in trust until works could be undertaken.

Federal Minister Peter Garrett (right) comparing Cerberus as she was with her current condition.

With funding currently not available to complete the whole stabilisation project, in 2010 approval in principal was given by the Federal Department of Heritage, Environment, Water & the Arts, to use the $500,000 grant to brace the gun turrets. The images below, commissioned by Friends of the Cerberus in 2010, illustrate how the bracing structure will appear when constructed.

Weighing approximately six tonnes, the central superstructure will still be lighter by approximately 67 tonnes than before the removal of the guns. In addition both turrets will be supported from the main armour belt which is eight inches (200 mm) thick. As the armour belt is made of iron it is still in remarkably good condition. The bracing structure will prevent the collapse that would otherwise irreparably destroy Cerberus.

The overhead, stern2 and profile3 images can be enlarged by clicking on each image. Click again to enlarge further.

The bracing structure consists of the following components:

• Armour Belt Beams. These I section beams which are 600 mm wide will be attached to the main armour belt and run the length of the breastwork deck (see overhead image). As the armour belt is under water these beams will not be visible from shore. The right hand end of the beam on the shore side of Cerberus may be visible at low tide.
  
  
• Beams on top of Turrets. Four of these I section beams (360 mm by 180 mm) will be attached to the top of each gun turret.
  
  
• Vertical Beams. These rectangular beams are 150 mm by 100 mm. They will attach to the beams on top of the turrets and the armour belt beams. These beams have been shown on the simulations as if the wide section faced outwards but most likely the narrow section will face outwards. In this case the beams will be 33% narrower than depicted. These beams will obstruct the view of between 5.2% and 7.8% of each turret.

¹ Photo courtesy of David Joy.
² Original photo courtesy of John Toogood.
³ Original photo courtesy of Lawrence Burr.
Bracing structure superimposed by Colin Bodie.