The British Royal Navy's HMS Iron Duke Type 23 Duke-class frigate has returned to sea after undergoing an extensive maintenance at the navy's facility in Portsmouth.

The frigate was put through a series of trials off the South Coast exercise areas following the sustained period of maintenance.

HMS Iron Duke’s guns, including the 4.5in gun, the automated 30mm cannon and the manual mini-guns, fired tracer and live rounds into the English Channel near the South Coast.

The ship’s command system combines all the data and information from sensors, and was also tested against simulated threats.

An Artisan 3D radar system is mounted on top of the frigate's main mast, which alone has the capability to track more than 800 potential targets at any one time.

The frigate also conducted helicopter training with a Wildcat aircraft from the 815 Naval Air Squadron at Yeovilton.

"This series of trials marks the start of the ship's emergence from a long maintenance period in Portsmouth and is critical to achieving our demanding programme in 2017."

Iron Duke commanding officer commander Steve Banfield said: “The ship's company are buzzing about being back at sea, conducting our usual business and building our operational capability.

“This series of trials marks the start of the ship's emergence from a long maintenance period in Portsmouth. The training is critical to achieving our demanding programme in 2017: exercise and security operations around the UK throughout the year.”

HMS Iron Duke performed NATO duties in the Baltic Sea and waters of northern Europe in the first half of last year.

The frigate is set to be deployed for Operational Sea Training this year, which assesses crew members and machines to ensure their readiness to perform front-line duties.

Image: HMS Iron Duke returns to sea after maintenance work. Photo: courtesy of Royal Navy.