The first of the Royal Navy’s new frigates, HMS Glasgow, sailed down the River Clyde for the first time on Wednesday.

She was escorted by Military of Defence Police from Clyde Marine Unit where she will eventually be lowered into the water for the first time.

Scottish shipyards have orders to build 13 frigates, with the type 31 vessels being built by Babcock at Rosyth on the east coast and the Type 26 ships being constructed by BAE Systems on the Clyde.

When HMS Glasgow touches water for the first time, she will be towed back up the Clyde to BAE Systems’ yard at Scotstoun where the work to fit the warship will be completed.

Last week, defence secretary Ben Wallace visited the vessel in Glasgow while it was being rolled on to the barge.

He told the PA news agency: “I think it’s a remarkable achievement by the workforce here, who’ve built basically the world’s leading anti-submarine warfare ship.”

Mr Wallace said the first Type 26 ship was coming out of the shipyard late but not “catastrophically” so, saying he is confident HMS Glasgow and the other frigates will enter service in time.

He continued: “The one thing (Russian President Vladimir) Putin is going to have left after his illegal invasion is a navy and an air force.

“He uses his submarines – and they are good submarines – very well to intimidate.

“We’ve seen worries about critical national infrastructure, gas pipelines, internet cables. We need ships that are going to hunt those submarines or deter them, and that’s the role the ships are going to take.”

Both the HMS Cardiff and the HMS Belfast are still under construction in Glasgow and are the Royal Navy’s second and third vessels.