The Olympic-class ocean liners were some of the largest and most luxurious passenger ships of their time. The Olympic, Titanic, and Britannic were built by Harland & Wolff for White Star Liners during the first half of the 1910s. While the sister ships stood apart because of their immense size and lavish accommodations, they all had powerful steam engines. Since the Titanic is the most famous of the ships because it sank (not to mention the James Cameron movie), we’ll cover how its engine worked before it sunk.
And if you’re a visual person? One helpful Redditor recently posted the video below to the subreddit r/educationalgifs. It’s part of a longer look at the Titanic from Jared Owen, who has got some pretty incredible 3D animations.
https://gfycat.com/zigzagessentialbee
Instead of choosing to go with a turbine engine, which was found on the Titanic’s main rival, the Cunard, Harland & Wolff decided to stick with two triple-expansion steam engines. The triple-expansion steam engines run on steam (duh) from the burning of coal in the ship’s boilers. Once the steam is made, it has a maze to run through before turning into power to move the ship.
Once the steam exits the boilers, it travels through steam lines toward the triple-expansion steam engines. The steam enters the first cylinder that’s called the high-pressure cylinder at 215 PSI to act on both sides of the piston to push it up and press it down. Once it’s done at the first cylinder, it moves on to the intermediate cylinder at a reduced pressure of 78 PSI to, once again, move the piston up and down. Then, the steam is routed to two low-pressure cylinders at 24 PSI to, you guessed it, move the pistons up and down.
After moving pistons up and down and dropping pressure throughout the trip, the steam exits the low-pressure cylinders at 9 PSI toward one of two nearly 24-foot diameter propellors. Exhaust steam escaping from the triple-expansion engines also powers a Parsons’ turbine to drive a central 16.5-foot diameter central propeller. The propellers caused the Titanic to move.
It’s incredibly advanced tech, and this is just a general overview of what’s happening. If you’re a numbers type of person, the triple-expansion steam engines were good for 15,000 horsepower each when operating at 75 revs per minute. The Titanic’s entire powerplant was rated at roughly 59,000 horsepower, allowing the 52,000-ton ship to travel at up to 23 knots.
While making that kind of power from steam is impressive, the way the Titanic ensured zero waste was just as skillful. Once the steam exits the Parsons’ turbine, it enters a condenser at 1 PSI. Cold seawater is brought into the condenser to cool down the steam, which allows it to go from a gas to a liquid to be sent back to the boilers to be used as feed water for another journey through the entire process.
The Titanic may be known for sinking, but getting a boat of its size moving on the water with steam was an accomplishment. Quite frankly, the rest of the ship was just as impressive, and well worth a look at the full video from Jared Owen.
