The Old Man and The Sea
Sentence parse:
"The successful fishermen of that day were already in and had butchered their marlin out and carried them laid full length across two planks//- with two men staggering at the end of each plank - //to the fish house where they waited for the ice trunk to carry them to the market in Havana."
The phrase with two men staggering at the end of each plank is what is called a parenthetical phrase.
A parenthetical phrase or parenthetical expression is a word or phrase
that is not essential to the rest of the sentence, but it isn’t
necessarily unimportant. It only means it doesn’t affect the
sentence’s grammatical structure.
If you remove the phrase, the sentence becomes:
The successful fishermen of that day were already in and had butchered their marlin out and carried them laid full length across two planks to the fish house where they waited for the ice trunk to carry them to the market in Havana."
So, "to the fish house" is preceded by the verb "carried".
Parenthetical phrases can be punctuated by commas, dashes or parentheses.
parenthetical phrases_Grammarist