Richard J. wrote:

But I wonder how he justifies the "more frequent" tag? According to
the press release, trains will run to Heathrow every 5 minutes, as at
present, with alternate trains serving T4 and T5. The T4 trains will
have a layover of 7 minutes at T4, so passengers for T123 should wait
and catch the next T5 train in order to reach T123 more quickly. So
T123 and T5 will effectively have a 6 tph service (every 10 minutes)
westbound, T5 will have 6 tph eastbound, and T123 will have 12 tph
eastbound.

I'm amazed that they think 6 tph will satisfy the demand for journeys
to T123 and T5, compared with 12 tph to T123 today. How on earth is
this "more frequent"? And if it's not more frequent, how can it
produce "increased capacity"?

But is the current Heathrow service 12tph? Last I heard, the Picc's 24tph
peak serivce dropped to something like 21tph between the peaks, and half the
trains went to Heathrow.

I'm interested that they will be running a longer line, yet there aren't any
new trains. Are they reducing peak service between Arnos and Cockfosters, or
west of Rayners?