There is one small fact not mentioned much in the media which may help make this blockade work beyond mere loss of income:
While Iran is chock full of crude oil, they have no actual refineries in the country for refining it into the various petroleum fractions like gasoline, diesel, etc., and so, actually get their gas from outside imported into the country.
With this blockade in place, Iran is running out of gas to run their cars, trucks, jeeps, and any other vehicle they have that runs on gas.
Pipelines cannot supplant the flow that usually goes out of the Gulf.
All that leaves is a railway out of the country to try to transport supplies in and out and all we need to do is blow up one bridge and that too is kaput.
Worse, if they cannot ship their export crude oil out of the country because of this blockade, their storage tanks fill up. Once they fill up, they have to shut down the wells.
Once they shut down their wells from pumping any more oil, they are a real ***** to get started up again.