On Sep 13, 8:26 pm, "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"?

Who knows - the problem here is that PiccEx Junction is incomplete;
there is no direct route for trains from T4 to reach T5 without a main
line reversal east of T123. As a result, T5 will get a permanent crap
service unless T4's service is drastically reduced.