The gauge pictured above measured the temperature pressure of 1 of 24 boilers on Queen Mary. An engineer can be seen in the other photo with a gauge like this one on the right side. The boilers were each 3 storeys high and weighed 100 tons. The “B. P.” indicates “Blowoff Pressure” which was maintained at approximately 425 degrees as can be seen on the gauge between the red indicators. The boilers used a crude oil called “Bunker C” which supplied the main turbine engines with 240,000 horse power. At full speed, Queen Mary thundered across the Atlantic at a normal speed of 32 knots. Queen Mary burned a gallon of Bunker C oil for every 8 feet she moved. She was the fastest ship in the world and held the Blue Riband until the liner United States broke her record in 1952. Sadly, the city of Long Beach, California which purchased Queen Mary in 1967 stripped all 24 of the boilers from their beds as well as the massive turbines which turned the propellers. Today, only the aft engine room remains.