How many intercontinental railways exist? And has USA built one of them?

There certainly is one and exactly one intercontinental railway between Africa and Asia: Suez Canal has the biggest swing bridge in the world, and it carries a railway.

There certainly is no intercontinental railway in Turkey: European railway ends in Constantinople, neither of the two bridges carries railway to Asia, and a Marmaray tunnel to Asia is under construction but not open.

There are certainly many intercontinental railways between Europe and Asia between Rostov on Don and Salekhard. Does anyone know the exact list of intercontinental railways in Russia and Kazakhstan?

There is 1 railway built by USA which might be intercontinental.

Is the Panama Railway entirely in North America, entirely in South America or an intercontinental railway?