Life on board Titanic's sister vessel revealed: Unseen pictures from the colossal 48,000-tonne hospital ship HMHS Britannic before she hit a mine in the Aegean Sea becoming the largest vessel to be sunk in WWI

• His Majesty's Hospital Ship (HMHS) Britannic sunk while returning from Greece on 21 November 1916
• Boats rushed to rescue her passengers and crew. As many as 1,030 people were saved and 30 lost their lives
• Unseen pictures have revealed its hospital wards, engine rooms and life on board the wartime vessel 

Hospital wards, engines and passengers on board the Titanic's colossal sister ship while she served in the First World War have been revealed in unseen black-and-white photographs.

His Majesty's Hospital Ship (HMHS) Britannic set sail in February 1914, but was requisitioned by the military before she could begin her first commercial voyage, and drafted in to battling against Germany and the Ottoman Empire.

She completed six voyages and transported thousands of wounded soldiers back to Southampton from the frontlines near Lemnos, Greece, before she hit a land mine in the Aegean Sea on 21 November 1916.

Boats nearby rushed to the rescue and saved 1,030 people on board including nurses, soldiers and sailors. Only 30 people lost their lives.

The 48,000-tonne Britannic went down in 55 minutes, almost two hours faster than the Titanic, becoming the largest ship to disappear beneath the waves during the war.

The images offering a tantalising glimpse into life on board 104 years ago have been revealed in The Unseen Britannic: The Ship in Rare Illustrations by Simon Mills.

The Britannic sunk on 21 November 1916 in 55 minutes after striking a land mine. Pictured above are nurses on her decks while she remained in service, bringing the wounded back to Southampton

Nurses and medical staff pictured relaxing on the ship's deck in 1916 as a soldier walks past

Two nurses smile out of one photograph showing the ships deck crammed with hospital beds while, in another, a soldier looks up at the camera from rows and rows of bunkbeds tightly fitted into a cabin. 

A second shows medical staff wearing coats and large hats relaxing on deck as soldiers walk past, and a third shows the engine room hidden below deck.

The ships's construction in 1912 is also revealed as a forest of scaffolding surrounding the gradually forming hull of the vessel.

Nurse Sheila Macbeth, 26, was on the ship when it hit a mine at 8am. She wrote in her diary, available in the collections of Edinburgh University: 'Up late - so only managed to get two spoonfuls of porridge before: Bang! and a shiver right down the length of the ship.

'Of course we all knew what it was! We had thought too much about torpedoes to be surprised to have met one at last. When the siren sounded, I went off to my cabin... and then hung over the side of the ship.

'In our boat, we got well away from the sinking ship and busied ourselves with the wounded, whom we picked out of the water.'

Nurse Sheila Macbeth, 26, was on the ship when it hit a mine at 8am. She wrote in her diary, available in the collections of Edinburgh University: 'Up late - so only managed to get two spoonfuls of porridge before: Bang! and a shiver right down the length of the ship.

'Of course we all knew what it was! We had thought too much about torpedoes to be surprised to have met one at last. When the siren sounded, I went off to my cabin... and then hung over the side of the ship.

'In our boat, we got well away from the sinking ship and busied ourselves with the wounded, whom we picked out of the water.'

Nurse Sheila Macbeth, 26, was on the ship when it hit a mine at 8am. She wrote in her diary, available in the collections of Edinburgh University: 'Up late - so only managed to get two spoonfuls of porridge before: Bang! and a shiver right down the length of the ship.

'Of course we all knew what it was! We had thought too much about torpedoes to be surprised to have met one at last. When the siren sounded, I went off to my cabin... and then hung over the side of the ship.

Captain Charles Alfred Bartlett, 43, was one of the most experienced skippers working on the vessel as it sunk - and was even involved with fitting out the Titanic.

He initially ordered for the engines to speed up, in an attempt to beach the boat, after they hit a landmine before conceding defeat realising this was causing water to rush in. The engines were stopped and the ship was evacuated.

Mr Mills said that, for her time, the Britannic was very much not a normal ship.

'True, she was Titanic’s sister ship,' he said, 'but seeing Britannic in her own unique context means we find a vessel that never served in the capacity for which she was designed.

'(However), as a military hospital ship in one of the most destructive wars ever, she played a vitally important supporting role in some of the most significant Allied campaigns during the First World War.

'The names of the thirty dead were all but lost in the mists of time, and as the first real book on Britannic was not published until more than three-quarters of a century after her loss, it is amazing that we now know as much about the ship today as we do.'

 condition.

She is 400-feet below the surface, compared to the Titanic's two-and-a-half miles, and lies on her starboard side in one piece, while the Titanic's wreck was split in two.

In February this year the Greek government considered relaxing legislation preventing visits to wrecks dated between 1860 and 1970, allowing visitors to go to the shipwreck.

The Britannic is too far underwater for most divers but experienced technical divers will be able to reach the wreck. Diver Carl Spencer, 37, died in 2009 from decompression sickness after undertaking an authorised visit to the vessel.

Other vessels that could become accessible due to the legislation change include a three-engined Luftwaffe plane off the coast of Paros, a World War Two British submarine and others.

Britannic is one of three ships, its sisters being the Olympic and Titanic. They were built by Harland & Wolff for the White Star Line shipping company and were dubbed Olympic class 'unsinkable'.

The Olympic was the only one not to disappear beneath the waves and was retired from service in 1935 and scrapped.

Britannic's construction was altered after the sinking of the Titanic to make safety adjustments including the provision of more lifeboats and ability to deploy them rapidly. It is the largest of the three ships.