Two other Titanic ships were built and had tragic endings as well

The Olympic class ships were a trio of British ocean liners built by the Harland & Wolff shipyard in Belfast, Northern Ireland, for the White Star Line during the early 20th century.

They were named the Olympic (1911), Titanic (1912) and Britannic (1914).

The White Star Line was owned by the International Mercantile Marine Company. This company was controlled by American financier J. P. Morgan, who played a crucial role in funding the construction of the Olympic-class liners.

All three liners were created by Thomas Andrews, the chief designer at Harland & Wolff, to be the largest and most luxurious passenger ships at that time.

In fact, the chairman of the White Star Line, J. Bruce Ismay, commissioned them in order to give his company an advantage in the transatlantic passenger trade.  

The most famous of the three, the Titanic, was actually the second built. She was launched on May 31, 1911, and entered service in April 1912.

The Titanic was widely regarded as unsinkable, but she struck an iceberg and sank on her maiden voyage from Southampton to New York, killing more than 1,500 passengers and crew out of the 2,224 people that were on board.

It remains one of the most tragic and iconic maritime disasters in history. But the two others, which are less famous, had both victories and tragedies in their careers. 

The Olympic was the first of the three sister ships to be built and was launched on October 20, 1910.

She made her maiden voyage on June 14, 1911, from Southampton to New York and had a successful career as a passenger ship, carrying celebrities, politicians, and wealthy travelers across the Atlantic.

The Olympic was the largest ship in the world until her sister ship Titanic surpassed her in gross tonnage in 1912.

She also served as a troopship during World War I, earning the nickname "Old Reliable" for her reliability and endurance. During the Gallipoli Campaign in 1915, she ferried soldiers to the battlefront in the Dardanelles.

The Olympic survived several accidents and collisions during her service, including a collision with a British warship in 1911.

During World War I, Olympic survived a torpedo attempt by a German U-boat, and instead famously rammed and sank the U-103, becoming one of the few ships to have sunk a submarine during the war.

She underwent several refits and modernizations over the years, including the installation of oil-fired boilers and new propellers.

Most importantly, in the aftermath of the Titanic disaster, international maritime laws were updated to ensure all passenger ships carried enough lifeboats for everyone on board, leading to the addition of extra lifeboats on both the Olympic and Britannic.

The Olympic continued to operate as a passenger ship after World War I, but faced increasing competition from newer and faster liners, such as the Cunard Line's Queen Mary and Queen Elizabeth.

She also suffered from the decline in demand for trans-Atlantic travel due to the Great Depression and the rise of air travel.

In 1934, the White Star Line merged with the Cunard Line, and the Olympic became part of the new Cunard-White Star Line.

She made her last voyage in March 1935, and was retired from service in April 1935 after an illustrious 24-year career.

She was sold for scrap later that year, and was dismantled in Jarrow and Inverkeithing, England, between 1935 and 1937. 

Parts of the ship, including her grand staircase and wood paneling, were auctioned off and repurposed in various locations, including a hotel in England.

The Britannic was the last of the three Olympic class ships and was also significantly modified to be safer than its sister ships after the Titanic sank in 1912.

Some of the changes included more lifeboats, higher watertight compartments, and lengthening the double hull sections. 

However, the Britannic never served as a commercial vessel, because it was completed after the outbreak of World War I in 1914.

The British government requisitioned the Britannic as a hospital ship, and it was renamed His Majesty's Hospital Ship (HMHS) Britannic.

It was the largest hospital ship ever constructed, with a gross tonnage of 48,158 tons.

The Britannic made five successful voyages to the Mediterranean, transporting wounded soldiers from various battlefields to England. 

On November 21, 1916, the Britannic was on its way to pick up more casualties from Greece when disaster struck near the island of Kea.

Initially, there was confusion about whether it had hit a mine or was struck by a torpedo. 

Regardless, the explosion damaged six of the watertight compartments and caused water to flood in through the open portholes.

The Britannic's captain, Charles Bartlett, tried to beach the ship on Kea, but it was too late.

The Britannic sank in less than an hour, taking 30 lives with it. Remarkably, despite the swift sinking of Britannic, over 1,000 passengers and crew were saved from the disaster due to the quick response of nearby rescue vessels and the lifeboat drills that had been held regularly on board.

Later examination confirmed that it had been sunk due to a collision with a mine, just two years after she had been completed and commissioned into service.

The Britannic remains the largest intact passenger shipwreck in the world, lying at a depth of about 400 feet (120 meters) in the Aegean Sea.

It was discovered by Jacques Cousteau in 1975 and has been explored by several expeditions since then.

The Britannic is considered a historical and archaeological treasure, as well as a memorial to those who died on board. 

The main differences between the three Olympic class ships were their size, design, and service.

Britannic was slightly larger than her sisters, with a gross tonnage of 48,158 tons, compared to 46,328 tons for Titanic and 45,324 tons for Olympic.

She also had a more powerful turbine engine and a larger rudder for better maneuverability.

In comparison, the Titanic had some minor design improvements over Olympic, such as an enclosed promenade deck on A-deck.

Although, as mentioned earlier, the Olympic did have some modifications after Titanic's sinking, such as the lengthening of the double hull and additional lifeboats.

Having said that, all three ships had different careers, with the Olympic serving as a civilian liner for most of her life and the Britannic serving as a hospital ship. 

So, while the Olympic and Britannic may not have had the same tragic end as their sister ship, the Titanic, they still had impressive and unique stories of their own.

The Olympic and Britannic may not be household names like the Titanic, but they are still worth remembering and exploring for their contributions to maritime history.