The most common and most likely answer to this crossword clue is the 6 letter word SEDANS
I've seen this crossword clue in The Guardian
S
E
D
A
N
S
Buddy explains!

The straight part
We know that "had to be carried" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case had to be carried = sedans.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SEDANS mean?
SEDANS noun- An enclosed windowed chair suitable for a single occupant, carried by at least two porters, in equal numbers in front and behind, using wooden rails that passed through metal brackets on the sides of the chair.
- An automobile designed in a configuration with separate compartments for engine space, driver/passenger space and luggage space.
- A handbarrow for transporting fish.