T5 testing.

Wonder if they will take these passengers on the Picc as part of the tests?

Possibly an evacuation exercise. They did one on the JLE before it opened.

It's already been discussed in another thread, I'm sure someone will have the link - I think it's the PiccEx thread in the Piccadilly Line subforum. I think some trains will do T4 and T123, others will do T123 and T5, then back to T123 then Hatton Cross, etc.

I wonder why it was unfeasible to build T5 station on the current loop

Don't get me started about this! The Underground to T4 saga was my first serious journalistic exercise I suppose, and I wrote a several-parter series in Underground News, using the then-current information including that gleaned from the GLC office that was organising the operations. There were in fact two Acts of Parliament in the end, as the alignment had to be moved in the end as a deviation from the original. The site of the anticipated T4 station was of course provided, but it was decided to place the station in a box inside the terminal building. That is the BAA made it available if the GLC/LT could in effect get their act together and agree to the proposal, etc. However, time ran out and the BAA then offered the second-best alternative of a box in the T4 adjacent car park.

However, whilst T4 was under way and the extension at proceeding, thought turned to a possible T5, to be located in the only available location, namely the Southern Water Board Perry Oaks sewage works or water treatment centre, which had always been there! The Water Board agreed to its removal/relocation if necessary and money provided. The problem is that whilst it was speculated that there would be a T5 at some stage, it was to be years away, and there had been enough delays and work associated with the T4 loop. However, it was stated at the time that any T5 would require a station for the tube and also possibly a SR extension line from Feltham, and clearly this station was going to be away from the alignment of the proposed T5. Of course in the end the T5 planning went to a mega appeal process with no guarantee that it would ever be built. Numerous changes were agreed at the T5 appeal hearing that could never have been anticipated previously.

I have to say therefore that speculation and allowance for a T4 station had come to naught previously, and despite knowing full well that in due course the T4 loop would be problematic and have accomodate a branch extension to T5, there was nothing that could be done. Then again the 1973 Tube Stock was never designed for wrong-way trains. The Central had the potential problem but lived with it, but the Picc had had to go to great lengths to turn trains coming off the Northern on transfer, because of the Kings Cross and Euston Loops. The problem of wrong-way trains on the Picc never seems to have caused any contention in the end, as I suppose it was a necessary evil.

If I was asked with nearly 30 years' hindsight as what I think about how the T4 and T5 extensions were laid out, I personally would suggest that hindsight is perfect, but if costs had not been of the essence, firstly Sub-Surface Stock could have been provided-for with a deeper cut-and-cover from Hounslow West, the Kingsley and Lampton Road bridges would not have been built to tube gauge, the Heathrow Central line under the airport would have been to SSS gauge, and the T4 loop built to a longer route spec to take in a possible, the only possible, location for a T5. The words "dog's" and "dinner" used to come to mind about the T4 extension but now in my senility I have to say that it worked in the end but opportunities were offered and missed.

Ah, TOK beat me to it ;D ;D ;D

I just thought since the current loop already gets pretty close to the Satellite #3 building, it may have been less of a logistical nightmare to throw in the T5 station there and make the cattle go on a system of moving walkways for the 1km trip to the main building! ;D

You may well be right on that but the specific location of every single (signal?) aspect of the layout of the T5 building and its accoutrements, including roads, car parks, etc. were trashed out, discussed and altered at the massive planning appeal hearing. I shall have to ask my mum who sat in on a the appeal for most of its existence as an impartial secretary, whether this was ever discussed. I doubt though that there was any way to fit the station in where you suggest, logically, it should be. As I said the BAA reserved a concrete box to be placed in the T4 terminal building but the offer was not able to be taken up for reasons highlighted in my post.

On a seperate point RAIL says that HeX are to run every 15 minutes to T5, and Connect will run to T123, then T4. HeX bovines, sorry passengers/customers, can get a free transfer from T5 to T4.