Boltar wrote:

Is there anyway that the Aldwych branch could be adapted for the purpose?
Or
does that require too much work to justify?

Probably not realistic since it only links to the northbound main line and
at
holborn the north and southbound lines are at different levels so you'd
need some sloping tunnel to be bored to link up with the southbound
line. Far too expensive.

Is it me or did someone set out to make the Aldwych branch next to useless
for the main Picadilly line?