G clamps on rails?

[truckman060473]

I guess these are placed to hold rails together during that super hot welding job, but any reason for these to be left in place, after completion of maintenance, as seen in Ferryside today where there was no engineering work taking place.

 

[GB]

I'm sure somone will be along shortly to correct me, but I believe the clamps are generally left in place if the welding job either couldn't be finished or had encountered problems.

 

[Peter Mugridge]

I've seen these used in lots of cases where there is wheel spin damage evident on the rail surface; in these cases they are obviously being used to re-inforce the rail to prevent it breaking until it can be replaced.

Looking at the photo again, there is evidence of wheel spin damage on that rail surface and there are two white marks nearby indicating a short length of rail to be replaced.

 

[truckman060473]

at a point where trains trundle past or are already up to about 30mph from the station how can a train's driving wheel lose adhesion here? Why does a rail join with a fault cause wheelslip?

 

[Trog]

Looks like a new weld that the welders are not quite happy with to me. The white paint marks are probably to make the marking of tell tales to see if the rail has moved during the welding / stressing operation easier.

 

[Old Timer]

As Trog has said, this is a set of emergency plates, which have been applied after the weld has "failed".

I am very intrigued by the paint marks, which are (a) too close to the weld to be acting as tell tales (marks which show where the rail has moved under stressing when it should have remained in situ) (b) shouldn't be on the new length of rail as a tell tale, as the anchor should be in the existing length.

 

[Trog]

I was thinking they might be tell tales to check if the gap had opened during stressing, rather than anchor length tell tales. I always used to put them as close in to the weld as I could myself. Although I used a pale red or green crayon, which shows up better on the rail than black pencil. So saving the need to put down a patch of white paint or chalk.

 

[Old Timer]

That would add up to a degree if the rail on the other side was not new....unless it was welded, clipped down and then pulled for some reason ?? which could of course would leave the section in the picture unstressed.

I have known one "Contractor" to have cut-in IBJs on stressed track at night on The GE without restoring the stress, because the General Manager did not give a bugger, and the site staff were (a) **** scared of the turd and (b) did not understand stressing.

When I found out and spoke with the Network Rail MPD PE he just buried the issue because NR were making the production figures, which would could not be achieved had the job been done properly.

On another area, the same man had new track going in into a dig full of water, rather than sort out the underlying drainage issue, as per the Contract. Again MPD were only interested in production, not what was really going on.

Amazingly Network Rail continue to give these cowboys work :roll: :roll: :roll:

Should be interesting when something drops off a 100 mph.

 

[Trog]

Drainage does not count towards the volume they are measured against. So as far as they are concerned it is expense and bother for no result. Just one of the perverse side effects of the way, the railways performance is measured against ORR / government targets.

 

[Old Timer]

Drainage does not count towards the volume they are measured against. So as far as they are concerned it is expense and bother for no result. Just one of the perverse side effects of the way, the railways performance is measured against ORR / government targets.

Sorry Trog, my meaning was that the drainage WAS included, in those particular works.

That said, I agree, and many sites now regularly encounter the results of poor drainage. Network Rail simple do not appear to understand the fundamental importance of drainage, and do not take any action to resolve drainage problems, even in locations where there are obvious drainage failures. They would rather relay straight into standing water because it keeps the Territory renewals figures up.

Another perversity is that of allocated renewal yardage, the application of which can, and does create absolutely stupid scenarios where "islands" of poor track are created, either because the yardage is measured wrongly (normally from the nearest 1/4 post rather than the reference point), or a previous shortfall is not included.

Yardages also do not recognise constraints such as sleeper volumes, and it is not unusual for a three tier sleeper salmon to be broken in order to reach the yardage. The unused sleepers then have to be unloaded (as the wagon cannot go forward partially loaded) and left lineside. Ths causes delays as the renewal times do not allow for this, and it costs money to uplift the sleepers, (usually by RRM and trailer at a later stage) and road them away.

You can then end up with a short section of say SHC in between G44s and F40s, and other similar stupidities.

There are incredible inefficiencies in track renewals that are really easy wins yet no one in I&I is interested, and if you do try to tackle these you are labelled a troublemaker. :roll:

If Network Rail removed the whole tranche of I&I leeches and set up Contracts direct with the Maintenance Engineer there would be no need to de-scope many of the Projects currently being cut back.

 

[Ploughman]

The white paint marks are roughly in the position that the welders would put their telltales to check for movement.
As a Tech If installing a new IBJ or similar I would have had chalk marks across either side of the cut point with a pencil mark at 500mm pre cut to check for opening.
Otherwise stressing telltales would be scribe marks in paint on the sleepers and rail foot.

 

[Old Timer]

I do not expect the welders to check for movement, that is the role of the Tech.

There is enough paint on the clips to paint the Queen Mary, it is only necessary to use a small mark.

When installing an IBJ there is only a need for a mark to be made at the initial cut point. The stressing weld is made at the current rail temperature calculation, and as many are made at night or in changing temperatures, the mark almost becomes irrelevant anyway.

Cutting a new section in on the basis of tell tale marks would only be acceptable if both the existing and the new rail were both at SFT at the current temperature, and this in itself requires the availability of the correct stressing records.

In my experience on renewals it is better to do a complete clean re-stress as many of the stressing records are either incomplete or missing or confusing.

 

[Ploughman]

Totally agree OT.
But the welders are required to mark up telltales on all welds. I believe it is one of the items that the Weld inspector checks.
Or did before I finished on the railway last year.
Telltales placed either side of the initial cut were for stress restoration purposes only and personally I always placed them on the back edge of the head so they did not get mixed up with anything else.
Telltales for stressing operations are a totally separate issue and would not normally be seen around the weld area.

 

[BFM31]

Hi Folks,
As a track welder myself i will try and put all your minds at ease, all track welders are required to put "datum marks" on the rail for every weld that is cast in track they are to be applied as soon as the rails have been set up across the head, running edge and foot either side using wedges to do this, datums are to be situated on the second sleeper either side of the weld and are there as a visual aid for the welder to check for rail movement.

As for the G clamps in the picture it could be a number of things that has happened for the weld to be clamped.

Rail movement after casting of the weld.
Gross porosity (moisture in the weld)
Chair Gall
Tensor slip
Black Holes