Grammaticality of "Shoreditch station to permanently close"

I recently read an article on BBC titled Bad grammar and the people who hate it. In it, there is a photo of a train station sign which reads as follows.

Friday 9 June 2006

Shoreditch station to permanently close

As part of the East London line project, Shoreditch station will permanently close to allow for a new line to be...

The fact that the sign has appeared in the article hints that there is something grammatically wrong with it. Although, for a non-native English speaker such as myself, it appears completely flawless.

What am I missing here?

The headline for the notice contains a split infinitive and no main verb.

Headlines can get away with not containing a main verb (which would be is in this case: "station is to..."), but some people class the split infinitive (eg "to permanently close") as a heinous crime against the language.

From the last couple of paragraphs in the article itself:

The split infinitive is the most celebrated of grammar conundrums. Henry Fowler, author of the Dictionary of Modern English Usage, published in 1926, summed up the debate as follows.

"The English-speaking world may be divided into (1) those who neither know nor care what a split infinitive is; (2) those who do not know, but care very much; (3) those who know and condemn; (4) those who know and approve; and (5) those who know and distinguish. Those who neither know nor care are the vast majority, and are a happy folk, to be envied by the minority classes."

In this case, rewording the notice as "Shoreditch Station to close permanently" does not upset line lengths since it's still the last three words which are together on one line, and it would not fall foul of any of Fowler's five groups.

The text of the notice contains "to allow for a new line to be built", which might also raise hackles. Allow for really needs to be followed by a noun phrase, not a verb phrase:

• ...to allow for the building of a new line
• ...to allow a new line to be built.

There is little to add to the answer above apart from the observation that American English seems to allow or even favour (favor?) the split infinitive. However as a native Englishman and a member of Fowler's group 3 it puts my teeth on edge (if I may be allowed such an expression).