Level 2 Stress in CWR, where Adjustment Switches are present.

[TheGreatISA]

Hey all,
I work for Network Rail in London and I am meant to be carrying out a Level 2 Stress. There are Adjustment switches present adjacent to my stressing site and I was wonder what is the distance that should not be stressed from adjustment switches.

It is Plain Line bit of track with Pandrol clips which is Standard Resistance; London end of the adjustment switches is CWR and Country end is jointed.
According to 3011 standards Page 16. Module 8.7 it states that 'Stress Transition length is 90 metres for high resistance fastenings. Standard and low is 180 metres' however according to Anchor points it mentions that it is 135 metres due to the low resistance on 3011 Standards page 21 9.6

Therefore Do I go for Option A or B? Also reason why?
A) Treat 180 metres from the adjustment switches as the non stressed length.

B) Treat 135 metres from the adjustment switches as the non stressed length.

From what I have been taught it is 180 metres but it contradicts in a way...

 

[DaleCooper]

Have I misunderstood this? To a layman it sounds scary that a Network Rail professional should be asking that question on here and presumably trusting the answer will be correct. Is it naive of me to say "Ask your boss"?

 

[3141]

Have I misunderstood this? To a layman it sounds scary that a Network Rail professional should be asking that question on here and presumably trusting the answer will be correct. Is it naive of me to say "Ask your boss"?

That's my impression too.

 

[TheGreatISA]

Have I misunderstood this? To a layman it sounds scary that a Network Rail professional should be asking that question on here and presumably trusting the answer will be correct. Is it naive of me to say "Ask your boss"?

I am working in accordance to what I have been taught and that is in reference to the Standards of 180 metres. I have asked my manager and he said 180 metres but there have been instances where people have treated it as 135 metres.
I merely posted this to gain an insight as to whether anyone else had come across this situation and what did they do.

 

[Domh245]

A general rule of thumb is surely to go for the "worst" case scenario. If some system has a component with a maximum allowable load of 100kg and another with one at 200kg, you go for the 100kg as the limit. In this case, I would have thought that a 180m length is the "worst" case scenario so that would be the one to be used?

 

[QueensCurve]

Have I misunderstood this? To a layman it sounds scary that a Network Rail professional should be asking that question on here and presumably trusting the answer will be correct. Is it naive of me to say "Ask your boss"?

My thoughts exactly. Something safety critical should be dealt with in house?

 

[godfreycomplex]

Remember that the number one rule of safety critical, well, anything, is if in doubt, stop and ask. This is exactly what the OP has done, public forum or no, ergothere's nothing really wrong with it.
Sadly I'm no expert myself, but as you say it is a contradiction (the 3011 standards condtradiction drinking game is good fun I gather, but that's for another day).
A does sound like the belt and braces option as Domh245 has said, however that potentially leaves a bigger unstressed gap than need be, causing endless heartache later and probably ending up less safe in the long run.
Not being an expert as I say I wouldn't like to advise a course, but discuss it with your boss if they're available, or if that fails the local gangers. There'll be a story about a similar situation out there somewhere.
Hope it all goes well anyway. There's no such thing as a stupid question on the railway

 

[GW43125]

There's no such thing as a stupid question on the railway

I've heard people say before "I'd rather answer your stupid questions now than fix your stupid mistakes later"

 

[alxndr]

135m is given as a minimum anchor length, so that reads to me as there are circumstances where it could be higher. Go with what your manager states, unless you think it's wrong, in which case, escalate it and/or state that you don't feel confident and competent to carry out the work.

[NB: Very much not my area, and probably not the best place to go asking.]

 

[Darbs]

I was taught 180 meters, what pandrol fastenings are they? (401a, e Etc) and have the adjustment switches been measured for the correct overlap measurements before doing anything? It's cwr on one side of the adjustment and jointed on the other?

 

[furnessvale]

I seem to recall that, many years ago, we used a formula something like 2 sleepers per degree of required destressing.

Of course, this bears no relation to modern methods.

 

[TheGreatISA]

I was taught 180 meters, what pandrol fastenings are they? (401a, e Etc) and have the adjustment switches been measured for the correct overlap measurements before doing anything? It's cwr on one side of the adjustment and jointed on the other?

The adjustment switches are set to the correct overlap as per the standards. It is a mixture of e-clips as well as pandrol clips as there are some wooden sleepers and some concrete. Several Track maintenance engineers have said that it is 180 metres but also some have said that it is 135 metres. I know that if you remove adjustment switches you would stress back 180 metres. This is done because that distance is unstressed... So surely it is 180 metres but at the same time if you've removed adjustment switches then you can stress 90 metres either side of where adjustment switches were.
It's quite contradicting to be honest

 

[Darbs]

As the adjustment switches are correctly set up I would and I always did go the 180 metres. It sounds like the track is a proper mixture of components! I would always inspect the length form the adjustment switch to the anchor point to check the correct clips are fitted and the condition and for any evidence of creep. If all is good I would go with 180 meters.

 

[Ploughman]

I was taught initially, in the early 90s, that the Anchor length was 90 metres and this was later revised to 135 if suspect or 90 if secure. (I finished in 2010 so any changes since then I know nothing about.)
The only time 180m came into the equation, was when removing a set of adjustment switches.

Reading from a 2006 TRK/0011 (p22 Para 9.6)
It says L1 = 90m minimum, but 180m minimum if Adj Switches have been removed at X