On Oct 8, 3:09*pm, Denis McMahon wrote:
A panoramio pic shows that the up platform ends at the overbridge anyway,
and although there is space between the bridge and the line, there would
be reduced headroom for passengers under the bridge if the platforms were
extended, as well as passengers having to move track side of the safety
line to pass under the bridge. Presumably extending the platforms in the
up direction would entail placing the arch span of the overbridge that
crosses the line with concrete or steel beams supporting the roadway,
which would I guess entail a significant possession of both the line and
roadway.

They seemed to manage just fine with the Boleyn Road bridge when
extending Dalston Kingsland's platforms not so long ago.