The S80 submarine.
The S80 submarine.

With a total surface area of 80 m2, each dome acts as an acoustic window and both protects and optimises the performance of the submarine's bow underwater detection and warfare sensors.

Under the current contract Tods will supply a total of four domes over the next four years. Each dome will be produced in three pieces by Tods and delivered to Spain for final assembly and installation.

The sonar domes will be fabricated from quadriaxial, carbon fibre/epoxy matrix prepreg using a resin film infusion process. Curing will be carried out in a purpose-built oven that has the capacity to take the entire structure.

The resin film process infusion process was chosen because it optimises the structural performance of the components by enabling much higher fibre fractions to be achieved than would be the case with contact laminating.

“We gained invaluable experience in building large composite structures for the UK Royal Navy but with the Navantia contract we have had to push the technical boundaries of composite material engineering even further,” says Steve Burton, Managing Director of Tods Defence.

UK-based Tods Defence specialises in the use of advanced composites for components destined for service in naval and military applications. Its bow sonar domes are in service with over 20 of the world’s navies.

The S80 submarine is a new design that Navantia has developed for the Spanish Navy.  It is 71 m long, has a diameter of 7.3 m and a displacement of 2400 tonnes. In addition to conventional diesel and electric propulsion systems, the S80 features an ‘air independent propulsion’ (AIP) system that will allow it and its 40 person crew to stay submerged for up to 15 days.