Hairballs in the tunnels?

I think it's true. I seem to remember watching some discussion about it on the TV show QI.

I've never seen hairballs but tunnel dust comprises mostly human hair and skin cells, quartz, metal filings and of course even today asbestos in small quantities.

Tubelines are meant to provide a Tunnel Cleaning vacuum train. Plus cleaning contractors use vacuum cleaners on backpacks!

Of course there needs to be a financial incentive. Station cleaning can earn the Infraco dosh through ambience scores whereas most customers dont see in the tunnels. (Though excess dust is blown onto stations)

I f you mean the original 1930s tunnel cleaning train I was always told that it had been a total failure.

By contrast the TCC did work but wasn't it due to be replaced, deemed to be at the end of its working life. I recall it being parked up at Northfields out of use when I was doing regular signal maintenance in the area a few years ago.

I'm not sure but I think fluffers disappeared around the time (early 1980s) that LT Cleaning Services moved from being a four station deep clean experiment to a full blown department with hundreds of employees.

Fluffers of course did not clean the tunnels, they did work into the tunnels but were not allowed more than 100 yards into a tunnel, apparently this being related to the Mining Acts though I don't know whether this was enshrined in laws applicable to the tube, or was perhaps the subject of union agreements. They were very effective at cleaning up the platform tracks and those parts of the tunnels that they did clean.

Of course signals used to clean the tunnels both deliberately and otherwise though in all cases it was relocating the dust rather than relocating it! Signal maintenance AETs used to use the signal compressed air supply to blow signalling equipment clean, that was deliberate.
When I worked on signal New Works we would drop the working cables from the bracket runs into balata straps slung from the bottom shelf to clear the runs for recabling during resignalling. It was a filthy job and we used to take a lot of dust home with us in those days as we had to wash our overalls at home. Of course the first train every morning would shift all the disturbed dust pushing it ahead creating dust clouds in the platform areas and covering anything light in little black clumps of packed fine particles. I recall once seeing a woman in a nice white suit waiting for the first train of the day and by the time the train had stopped in the platform it was a speckled white suit.

These days signal TOs and their assistants still clean signalling apparatus using an assortment of brushes but again this is disturbance rather than collection. In my last years as a TO down the pipe I saw various methods of cleaning undertaken by contractors including sieving the ballast and using trolley mounted industrial size vacuum cleaners.

Absolutely true. Brake shoes were of cast iron, but they went through a load of experiments through the years.
I spent a lot of time in depots in the 1960s (because I could!) and never missed an opportunity to crawl under trains and strike-up friendships with the army of specialists that kept the trains running. That included me looking at brake blocks (anyone who knows me will understand why I had an interest in that particular piece of train equipment ).
At that time 1938TS had some really chunky composite blocks. Many of them were a dark-brown, but sometimes I would see light-brown, grey and black versions as LT tried out new materials.
A lot of the composite shoes had small particles and sparkly bits in them to varying degrees as different mixes of materials were tried. I distinctly remember asbestos being mentioned as one of the substances that was added to some of the shoes.
Stations such as Highgate and Hampstead southbound, which were approached down steep gradients, were always full of dust - it was often like a fog if a couple of the preceding trains had made heavy brake applications. Goodness knows what we were breathing in. I certainly remember the brake shoes giving out a very distinctive smell that I would describe as uncooked smoked bacon, although I doubt if that was the asbestos.
Early electric trains also contained a lot of asbestos. Even standard stock had it in places like switch cases and I certainly remember seeing pipes at stations with asbestos fabric wound round them and secured only with wire. I believe that asbestos particles were also used at one time in the material that encased the windings in the motors, although I cannot confirm that. I always understood that the high voltages used in control circuits made arcing inevitable and so asbestos was a material of choice.
Asbestos was also quite common at the back of heaters and cookers at stations, and was quite often cracked or broken. Like many things in those days, when it became unfit for purpose or was replaced, it often got thrown behind the sand-bins on platforms in the hope that a p-way crew might pick it up with their rubbish!
As a result of all of these examples, I would think that it is quite likely that some found its way into the tunnels.
The only question is, what type of asbestos was it?

I think you'll find that there will be a programme of regular filter replacement to ensure it functions correctly.

Other systems will have coped with dust at these levels in the past and I'm sure it will be within the abilities of the manufacturers.

They removed asbestos from Brixton (2004?) and Victoria recently.

Melamine ceilings were removed from stations after the King's Cross fire and replaced. (Though not at Charing Cross Jubilee)

Is that the one that cleans/recycles ballast???

I think so I asked about it a year or so ago if somebody can find the thread.

There were some photos but can't remember where I saw them!

I'm sure there's a tunnel cleaning train that works somewhere too!

Thanks Rob, that looks like the train I see, although when I see it the arm is stowed along the roof line.

Sound proofing for the occupants within the train. The older stocks were noisier because of single glazing and opening windows. In the 1930s Pick wanted the UndergrounD to be the first railway in the world to have air conditioning installed. Needless to say.....