R A T, and the leaf fall season.

Does it require a separate operative to work the Sandite equipment, or can this be done by the driver?

is only a matter of time, but with so much new rail head laid the last year or so, lets hope its a good season.

the furthest south the RAT gets is Neasden Depot

Which probably why the fifth car was removed! Does 6036 still have its compressor?

I think the sandite equipment uses the brake gear, thats why no brakes. Not sure about compressor, I will have to findout. Stanmore? not sure.

Anyone know the times this operates?

I assume this is subject to the usual caveats (run early/not at all etc)?

Bad flats on some on the motor wheels, but metronet were told not to stop the unit over the weekend for wheel turning.

It was due to be done after the weekly exam on sat, they even got extra staff in, but the plans changed after a call from london underground.

04:30 Aylesbury-Neasden via Wycombe
05:55 Neasden-Aylesbury via Amersham
09:35 Aylesbury-W Ruislip via Wycombe
11:13 W Ruislip-Aylesbury via Wycombe
13:40 Aylesbury-Marylebone via Amersham
15:04 Marylebone-Aylesbury via Amersham
21:10 Aylesbury-Marylebone via Amersham
22:43 Marylebone-Aylesbury via Wycombe & Bicester

Sorry, should've said that they're Monday-Friday.

Weekends are variable depending on the different engineering work possessions that take place.

Now I'm not the most radical thinker in the world, I'm simply a Grunt who drives a Metropolitan line Underground train. Generally speaking, the most important things I have to worry about in any given day are 'green for go, red for stop' and what to have for lunch. Yellow takes a bit more thinking about but generally one can work out what it means without too much ache of the brain. However, maybe somebody out there in DistrictDaveLand can put me straight on the following because for the life of me I cannot work out how this makes any kind of sense and I don't wish to overload the old grey cells. After all, I've got lunch to think about.

The annual Leaf Fall Season (I think it's called 'Autumn' in the real world) is a big deal for London Underground. Special timetables are produced enabling Drivers to cut maximum speeds between Amersham / Chesham and Moor Park by some 20% so as not to slide straight past Chorleywood on a gungy layer of leaf slime and mulchy brown detritus. Information posters are displayed in Mess Rooms, Booking-On points and just about anywhere else a Driver is likely to go in the course of a day and a special little gatefold memocard is distributed to remind us all about defensive driving, early braking and what to do when it all goes Pete Tong.

In addition, the R.A.T. trundles up and down the line laying an abrasive surface of Sandite to the railhead which serves to increase the chances of us actually stopping the train in the right place whilst also helping to reduce wheel slip when subsequently attempting to depart. Over and above the actual cost of the Sandite itself, this operation takes up several driving Duties throughout the day and involves the attendance of a Metronet technician to turn the pumps on and off across the points etc. In short, it can't be a cheap and nasty answer to the annual problem of Autumn upsetting the smooth running of the Metropolitan line and would surely be one London Undergound would dispense with if they could.

Why then, and this is what really baffles me in between bacon sandwiches, does London Underground then allow Chiltern Railways to run a hissing, steaming clanking diesel-driven 'Heath Robinson' high-pressure water squirter along the same sections of track, quite effectively washing away all traces of Sandite and adding an artificial layer of slipperyness to otherwise dry track conditions? To follow on behind this particular solution to 'Leaves On The Line' during it's passage south from Amersham is interesting, to say the least.

I'm sure I must be missing the big picture here because London Underground wouldn't just toss money away in this manner ............ would they?

From what little I understand of the process I think that there is a finite limit to how many layers of sandite you can have on the railhead. Too much and you're back to square one (bit like the anti-foaming that the Snowdon used to use in it's boilers - too much and you'd end up with an irreversible water carry over as the engine was pounding up Snowdon).

I *think* that you need both attacks - the RAT and the Chiltern in order to prevent the sandite turning into gritty leaf-mulch that is just as good at letting Motormen skid through Chorleywood as the leaf mulch itself. ;D

True, for your train - however you will have dried the railhead nicely for any moves after you.

I *think* that you need both attacks - the RAT and the Chiltern in order to prevent the sandite turning into gritty leaf-mulch that is just as good at letting Motormen skid through Chorleywood as the leaf mulch itself

Not that I go around examining the track but I can't say I've noticed several layers of Sandite building up on the railhead. It gets kinda dispersed by the passage of the trains otherwise there wouldn't be the need for several passes of the R.A.T. each day. Then, along come the tenants who simply add a slippery glaze to the railhead. It's not even that the water jet flushes out the points because, in theory, the Sandite is not applied across junctions.