Grammar

2.309 with comparative adjective groups

Nouns and pronouns can be followed by a comparative adjective plus 'than', or by adjectives in various structures which indicate degree or comparison.

...sculptures larger than houses.
...a pig as big as a cow.
...steel cylinders strong enough to survive even a nuclear catastrophe.
They march in columns so long they may take several hours to pass one spot.

The use of comparative adjectives plus 'than' after noun groups is explained in paragraphs 2.111 to 2.113. Other ways of comparing things are explained in paragraphs 2.128 to 2.144.