how are faults found on railway tracks?

Question

especially on huge networks such as the London underground.

Answer 1

Several ways!

First is normally when a Passenger comments on the condition of the Track.
The Otherways are when a driver reports a "rough part" when he drives over the tracks.

Network Rail 'NR' have several yellow coloured trains which are full of very sensitive equipment such as ultrasound and radar technogolgies. I belive these are called Network Rail New Measurement Train, (or at least thats what it says on the side of the Yellow HST). These trains also test new equipment.

There are also gangs of people who will, or are meant to, check track on a regular basis using a track mounted tool kind of like a wheel which will montor track cracks.

On the London Underground, there are a load of people who start work as the network starts to shut down (remember the Underground starts shutting down at different times across the network). Once the power is confirmed as off they walk the entire network checking for faults.

Answer 2

You look for them!

These days, technology helps as specialist rail-vehicles have been constructed to ultrasound the track for inherent faults.

But the majority of faults can, and should, be detected by sight.

In the good old BR days (remember them?), each length of track was the responsibility of a P-way man ("p-way" is "railway-speak" for "Permanent Way", which, in essence is the track and trackbed). Each P-way man walked his track on a regular basis. Although this was usually once a fortnight, on more heavily used sections it would be more frequent.

On finding a fault, the P-way man had various options. Minor repairs, such as missing bolts could be replaced there and then. Some work would have to be undertaken by specialist gangs. But, if a potentially dangerous situation was found, the P-way man had the facility (and responsibility) to set all the signals to red (ie Stop!)

But P-way men are a labour-intensive solution, and, hence, expensive. As successive governments sought to reduce the cost of running the railway, P-way men have been one casualty.

P-way inspection on the London Underground is done after the passage of the last train and before the first train next day, because the power has to be switched! Their specialist maintenance vehicles tend to be battery operated. (The need to do these inspections is the reason why the London Underground cannot provide a 24 hour service other than for special occasions).

Answer 3

Every night there are gangs of people who walk the hundreds of miles of tube network, when all the trains have been stopped. That is why London Underground close down over night so that the safety checks can be completed.

Answer 4

Network Rail have a variety of trains which travel over the network on a regular basis, these trains carry out various tests and inspection of the lines and there surroundings, these trains test for rail condition (Ultrasonic testing), track ride quality, structure guageing, condition of the overhead wires etc. There are around 8 trains which travel around the UK carrying out this work.

Answer 5

There are engineers who walk the tracks periodically checking for visable damage.

The tracks are also scanned every now and then by a track mounted vehicle to check that the actual metal is still of good quality and has not deteriorated/cracked inside.

Answer 6

Railways tracks have a "shelve life" when they have to be replaced but are routinely checked manually and by engineering trains using ultra sound

Answer 7

a rail detector car which is filled up with a bunch of electornic equipment that detects flaws in the track and also by human eyes aperson whom walks the tracks and looks for more obviuos shortcomings

Answer 8

The concerned authorities check manually for any visible damages or crack and for a thorough checkup of the rails they use Ultrasonic Transducers which gives the clear information of any internal cracks

Answer 9

They use Track walkers for any visible signs of damage, and also
ultrasound in maintenance vehicles which scans and records the
track as it goes along.

Answer 10

The answers given are quite accurate and I believe these aforementioned specialized rail vehicles, with the sensitive instrumentation, are referred to as "Geometry Trains".