Image copyright MOD Image caption Lieutenants Maxine Stiles (L), Alexandra Olsson (C) and Penny Thackray (R)

Three women have become the first female submariners in the 110-year history of the Submarine Service.

Lieutenants Maxine Stiles, Alexandra Olsson and Penny Thackray earned their "Dolphins" after months of training, including operations on HMS Vigilant.

Defence Secretary Philip Hammond hailed their "huge personal achievement" and said it was "an historic moment for the Royal Navy and our armed forces".

A ban on women submariners based on health fears was lifted in 2011.

A review of concerns that submarines' higher levels of carbon dioxide could carry risks to female health decided the fears were unfounded.

Lt Olsson, 26, from Tranmere, the Wirral, described joining the 165 male fellow crew members of HMS Vigilant as like living "as a very strange family".

"I felt like a little sister to 165 brothers," she said. "At the end of the day manpower is a big thing for the navy - as long as you can do the job, it doesn't matter."

She added: "Of course it's been challenging, but women are absolutely capable of doing this job. I think that change can always be a bit of a shock, but I look forward to seeing more and more women getting on board."

'Whole new world'

Lt Stiles, 29, from Ashton-under-Lyne, Greater Manchester, said: "As long as you can do your job and you're good at what you do, I don't think they [the crew] cared whether you were male or female."

Describing the experience of being away at sea on a submarine, Lt Thackray said: "You limit your horizons. I found I just forgot about the existence of some things.

"Someone asked me if I missed bananas, I hadn't even noticed until they mentioned it.

"I just forgot the outside world - you get a whole new world," said the 39-year-old from Hightown in West Yorkshire.

Image copyright MOD Image caption Their training included operations on HMS Vigilant

Lt Stiles will continue as a logistics officer on board HMS Vigilant, while Lt Olsson is undertaking deputy weapons engineering officer training. Lt Thackray is due to become an education officer.

HMS Vigilant's commanding officer, Cdr Matt Dennis, said: "I was impressed with how seamlessly the three women integrated on board."

He added that they had "really paved the way for women on submarines to be business as usual from now on".

Second Sea Lord Vice Admiral David Steel said: "Women have been serving in ships at sea with the Royal Navy for more than 20 years and integrating them into the Submarine Service completes their inclusion into all seagoing branches."

The Royal Navy first allowed women to go to sea in 1990.