It's about one-and-three-fifths times as heavy as The Statue of Liberty
In other words, 40,000 tonnes is 1.62 times the weight of The Statue of Liberty, and the weight of The Statue of Liberty is 0.617 times that amount.(a.k.a. Liberty Enlightening the World, a.k.a. La Liberté éclairant le monde) (total weight, including foundation)
The total weight of the Statue of Liberty, including her base is roughly 24,600 tonnes. The statue was designed using an optical trick known as "forced perspective" to make the statue appear proportionally correct when viewed from its base and is, in actuality, disproportionately large at the top.
It's about one-third as heavy as The CN Tower
In other words, 40,000 tonnes is 0.33924 times the weight of The CN Tower, and the weight of The CN Tower is 2.9478 times that amount.(a.k.a. La Tour CN, a.k.a. Canadian National Tower, a.k.a. Canada's National Tower) (Toronto, Canada)
The CN Tower weighs approximately 117,910 tonnes. The Tower is home to the world's highest glass floor — a viewing area that allows visitors to look straight down 342 m (1,120 ft) to the ground below.
It's about three times as heavy as The Brooklyn Bridge
In other words, 40,000 tonnes is 3.00 times the weight of The Brooklyn Bridge, and the weight of The Brooklyn Bridge is 0.333 times that amount.(a.k.a. New York and Brooklyn Bridge) (Manhattan and Brooklyn, New York City, New York) (total weight)
The total weight of the Brooklyn Bridge is approximately 13,320 tonnes. In a promotional event to prove the bridge's stability shortly after it opened, entertainer P. T. Barnum led a parade of 21 elephants across it in May of 1884.
It's about four times as heavy as The Eiffel Tower
In other words, 40,000 tonnes is 3.96 times the weight of The Eiffel Tower, and the weight of The Eiffel Tower is 0.253 times that amount.(a.k.a. La Tour Eiffel) (Paris, France) (total weight)
The Eiffel Tower weighs approximately 10,100 tonnes. Architected to be quickly assembled, the Tower contains only 930 cu. meters of solid material.
It's about one-fifth as heavy as The Sears Tower
In other words, 40,000 tonnes is 0.1982 times the weight of The Sears Tower, and the weight of The Sears Tower is 5.05 times that amount.(officially "Willis Tower" as of 2009) (Chicago, Illinois)
The Willis Tower weighs approximately 201,800 tonnes. The outer wall surface of the Tower is covered with black anodized aluminum panels which would total 110,000 sq. m (28 acres) if laid out together.
It's about one-tenth as heavy as The Empire State Building
In other words, 40,000 tonnes is 0.121 times the weight of The Empire State Building, and the weight of The Empire State Building is 8.26 times that amount.(New York City, New York)
The Empire State Building weighs approximately 331,000 tonnes. About 4% of the building's weight is its 6,000 cu. m (200,000 cu. ft) of limestone façade.
It's about one-twentieth as heavy as The Golden Gate Bridge
In other words, 40,000 tonnes is 0.050 times the weight of The Golden Gate Bridge, and the weight of The Golden Gate Bridge is 20.1 times that amount.(San Francisco, California and Marin County, California) (Post 1986 weight reduction; total weight of bridge, anchorage, and approaches)
Following the completion of the 1986 project to eliminate excess material, the total weight of the Golden Gate Bridge — including its anchorages and approaches — is 805,000 tonnes. The two main cables in the spanning the bridge are spun out of a total of 129,000 km (80,200 mi) of wire.