Ballast over the sleepers

[richard w]

I've seen this in various places over the years but still don't know if theres a reason for it?  I'd be interested in modelling the effects on my new layout, but would appreciate any input as to the placement of it.  I'm modelling the western region in 1989.

 

I took these on the Midland Mainline in 2010.  The first shows excess ballast both between and outside the rails on the slow lines.  The second shows excess only on the outside of the rails for the fast lines.  Both taken from the same location at the same time.

 

 

Is there a genuine reason for this or is it just something random that happens?  Thanks for the help.

 

[Mike Storey]

Where ballast is left like this, it is almost always awaiting a run or three with a tamper machine (after a relaying job, or ballast cleaning), which will vibrate the ballast down to sleeper level.

 

Ballast is not deliberately left above top of sleeper level in the four foot, on any long term basis, these days.

[richard w]

Ah, that would explain why the ballast in question is fresh.

 

Thanks Mike.

[Southernman46]

Not really a problem until it covers the rail fastenings except visibility of the sleepers to check for rot or cracking between the housings is necessary - this was the situation at Kew some years ago where a number of consequetive concretes were split laterally on the tight curve around to the LMR but were covered in ballast / flood spoil and the road then spread under a 47 despite the HSTRC indicating a gauge fault at the site ........................

[sem34090]

Harrumph...

 

I was led to believe that this practice ceased around 1900, on the LBSCR at any rate!

The effect is quite plain to see in this photograph of a fine example of modern passenger motive power! An E4. Oh how I wish Bachmann had produced the class in this condition: it's so much more elegant!

[phil-b259]

Where ballast is left like this, it is almost always awaiting a run or three with a tamper machine (after a relaying job, or ballast cleaning), which will vibrate the ballast down to sleeper level.

 

Ballast is not deliberately left above top of sleeper level in the four foot, on any long term basis, these days.

 

Au contre - virtually every job I have seen (with the possible exception of around relaid point work) has plenty of ballast on top of the sleepers.

 

Removing excess ballast, like removing scrap is frequently not treated as particularly important as far as I can tell and while time may well be allocated to it during the planning stages, should problems manifest themselves then making things look pretty / tidy is one of the first things to be ditched so the possession can be given up on time.

 

Thing is covering wooden sleepers with ANYTHING - be it ballast or indeed loco ash as was the fashion in the 1800s simply encourages the wood to rot faster as they never get a chance to dry out or 'breathe' as it were. Covering the sleepers obviously also makes it harder to see said rot, so all in all it is practice best avoided.

 

However concrete and steel sleepers are a very different matter as they are don't rot* As such you can quite safely cover them in ballast and it has zero effect on life expectancy - though it obviously still has the potential to hide defects such as a cracked concrete sleeper (which allows water to get in and rot the reinforcing steel). This 'excess ballast' is also helpful as to prevent CWR buckling then you need plenty of ballast packing the sleepers anyway - so better to have to much than too little.

 

* Unless damaged concrete sleepers don't mind being soaking wet all the time, and the steel variant uses special steel where the rust on the surface does not propagate through the metal as it were.

Edited April 4, 2018 by phil-b259

[Ncarter2]

Removal of excess ballast will become a priority as PLPR goes live over a section. It needs to be able to see the track components. Part of the system creates a ballast report, it also highlights locations of obstructed fasteners.

 

With concrete sleepers, care needs to be taken with regards to known sites on concrete cancer, so leaving excess ballast can and does mask problems that bite the rear end.

 

Too much ballast can also, in wet weather lead to TC failures or flicks, especially on steels.

[DCB]

The excess ballast will soon be covered with the usual carpet of weeds if the local Swindon Gloucester line is anything to go by.

That 6ft is a lot less than Peco points give in 00

Edited April 5, 2018 by DavidCBroad

[rodent279]

Changing the subject slightly, wet spots used to be a big problem, especially on the WCML. I rarely see them now-why is this?

Has anyone tried modelling a wet spot?

[Trog]

Changing the subject slightly, wet spots used to be a big problem, especially on the WCML. I rarely see them now-why is this?

Has anyone tried modelling a wet spot?

 

There has been a lot of ballast cleaning in recent years mainly with the HOBC hence fewer wet spots. However should they stop the ballast cleaning the wet spots will soon return.

[Trog]

As to the amount of ballast dropped there should be a 5" high shoulder of ballast off the sleeper ends on the cess side of CWR track, and where there is a wideway between tracks with a width such that the ground surface is lower like the cess should be so as to facilitate drainage. The raised shoulder is intended to increase the resistance to lateral movement in hot weather. The sleepers themselves should not be covered in stone, to allow maintenance, for inspection and because it makes walking on the track hazardous.

[Mike Storey]

Au contre - virtually every job I have seen (with the possible exception of around relaid point work) has plenty of ballast on top of the sleepers.

 

Removing excess ballast, like removing scrap is frequently not treated as particularly important as far as I can tell and while time may well be allocated to it during the planning stages, should problems manifest themselves then making things look pretty / tidy is one of the first things to be ditched so the possession can be given up on time.

 

Thing is covering wooden sleepers with ANYTHING - be it ballast or indeed loco ash as was the fashion in the 1800s simply encourages the wood to rot faster as they never get a chance to dry out or 'breathe' as it were. Covering the sleepers obviously also makes it harder to see said rot, so all in all it is practice best avoided.

 

However concrete and steel sleepers are a very different matter as they are don't rot* As such you can quite safely cover them in ballast and it has zero effect on life expectancy - though it obviously still has the potential to hide defects such as a cracked concrete sleeper (which allows water to get in and rot the reinforcing steel). This 'excess ballast' is also helpful as to prevent CWR buckling then you need plenty of ballast packing the sleepers anyway - so better to have to much than too little.

 

* Unless damaged concrete sleepers don't mind being soaking wet all the time, and the steel variant uses special steel where the rust on the surface does not propagate through the metal as it were.

 

Tamping is usually done up to a week or so after the renewal (although that was being speeded up with some new equipment by the time I left, on plain line), which is why you see the ballast "left" at the end of a job. 

[iands]

Changing the subject slightly, wet spots used to be a big problem, especially on the WCML. I rarely see them now-why is this?

Has anyone tried modelling a wet spot?

Quit a bit of "spill deposits" from freight trains (coal/MGRs in paricular) contributed to wet spots by clogging up the natural drainage. Also local clay deposits in the track foundation didn't help with drainage. Now that most of the coal traffic has ceased (compared to just a few years ago), and therefore less "spill", may well contribute to less wet spots being experienced.

 

Regards, Ian.

Edited April 5, 2018 by iands

[Pandora]

I am tempted to post a puerile comment, but I will refrain....

I believe that much of the WCML is not tamped, but "Stone-Blown"  Stone blowers inject fine chippings below the ballast, stone blowing with  chippings is  equivalent to measured shovel jack and pack. Fine chippings do not grind and grate together as trains pass over and there is not the break down into water-loggged  ballast dust which results in a wet bed.  

 

Wet bed is a mis nomer,  the way tools just bounce off you would think they were spillages  of  airport runway concrete

Edited April 5, 2018 by Pandora

[Ncarter2]

I believe that much of the WCML is not tamped, but "Stone-Blown" Stone blowers inject fine chippings below the ballast, stone blowing with chippings is equivalent to measured shovel jack and pack. Fine chippings do not grind and grate together as trains pass over and there is not the break down into water-loggged ballast dust which results in a wet bed.

 

Wet bed is a mis nomer, the way tools just bounce off you would think they were spillages of airport runway concrete

With such a small fleet of operational stone blowers there wouldn’t be enough to cover the full west cost and the rest of the country.

 

Tamping is the preferred method, stone blowing is used in places where tamping has failed to maintain the geometry to a satisfactory level for a set period of time. Formation issues also dictate is blowing is better than tamping. The west cost is mainly set to Absolute Track Geometry. This means the tampers effectively get told where to put the track to allow for the pendolinos to tilt and do 125mph through curves where conventional stock will have to slow down. A track design as it where. Stoneblowers can work on ATG track but are not as aqurate, they are given a Window to work to. This is mainly why the fast lines are tamped. It’s not as easy to send a blower out either. You select the category you want from the machine and depending on the measuring run will dictate which category is available. The blower also over lifts by 40mm on any lifts to allow the stone to get in and for settlement. They are fantastic machines but much suited to poor track, the type with contaminated ballast and such, not a high speed ATG route. Having been a previous OTM tech based at Rugby I know we rarley used them on the Fast lines neither did the Southern half of the Route up to Stafford’s/Stoke way. Past there I couldn’t say I we rarely ventured past there.

[Ncarter2]

Changing the subject slightly, wet spots used to be a big problem, especially on the WCML. I rarely see them now-why is this?

Has anyone tried modelling a wet spot?

 

Take a trip on Wessex, you will soon change your opinion.

[Trog]

In my experience there are two sorts of wet bed, those caused by a voiding sleeper working in its bed and grinding its underside and the surrounding ballast into a powder. These can be shallow and 9" under the sleeper the ballast is fine, but the sleepers are sitting in their own little bath tubs of water. It always amazed me how they managed to hold the water in as with the pounding they got you could not have done that with a steel trough. This sort of wet spot are usually a colour based on the stone used for the ballast. Nuneaton ballast being somewhat red was why most of the wet beds on the south end of the WCML were that nice shade of pink.

 

The other type of wet spot are those caused by formation failure, with clay working up from under the ballast and sleepers. At first this is just a thin line of slurry up the side of the sleeper under and beside the rails, where the greatest load is. The slurry line then lengthens along the sleeper side also getting thicker as more clay comes up and the problem gets worse, these wet spots are usually coloured by the underlying clay and tend to be more grey or brown in colour.

 

Both sorts of wet spot tend to breed if not smartly and properly attended to. Stock drops into the original wet spot dip then climbs out rising on its suspension as it reaches level track again. The stock then recompresses the suspension causing an impact load on the track, this often causes a second wet spot, and the second a third, and before you know it you have a cyclic top problem with a wet bed in every dip.

[phil-b259]

Take a trip on Wessex, you will soon change your opinion.

 

Same for Sussex, and no doubt Kent.

 

I carn't help feeling the old 'its only a glorified tramway' mentality lives on in certain circles, OK it may not have super fast express trains or lots of freight, but intensive EMU services are very good at exposing track deficiencies

[Ncarter2]

Same for Sussex, and no doubt Kent.

 

I carn't help feeling the old 'its only a glorified tramway' mentality lives on in certain circles, OK it may not have super fast express trains or lots of freight, but intensive EMU services are very good at exposing track deficiencies

More intensively used than most might want to accept. Basingstoke to Eastleigh being two line sees a massive amount of traffic, it’s hammered by freight all day and night as well as the commuter units. 100mph line speed, some very unstable embankments - all adds up to a interesting section to keep going.

[phil-b259]

More intensively used than most might want to accept. Basingstoke to Eastleigh being two line sees a massive amount of traffic, it’s hammered by freight all day and night as well as the commuter units. 100mph line speed, some very unstable embankments - all adds up to a interesting section to keep going.

 

And with con rail that automatically chops over an hour from the 'working time' when possessions are organised due to the way isolations have to be done.

[jim.snowdon]

And with con rail that automatically chops over an hour from the 'working time' when possessions are organised due to the way isolations have to be done.

Although that is being worked on, essentially by dispensing with the need to send men out to odd places on the track to fit short circuiting straps and instead sending them to operate lineside switchgear that is located at places that are safer and easier to access.

 

Jim

[Ncarter2]

Although that is being worked on, essentially by dispensing with the need to send men out to odd places on the track to fit short circuiting straps and instead sending them to operate lineside switchgear that is located at places that are safer and easier to access.

 

It’s been worked on for some time now, none of us are optimistic it will be any time soon. Also not all have been situated in ideal locations. Fareham could have be thought about, and other locations don’t look like a great deal of thought has gone into it. It would be fantastic if for once, those of us who actually man and staff these possessions and isolations, actually had a say. But why apply logic on the railway.

 

Jim

 

Although that is being worked on, essentially by dispensing with the need to send men out to odd places on the track to fit short circuiting straps and instead sending them to operate lineside switchgear that is located at places that are safer and easier to access.

 

It’s been worked on for some time now, none of us are optimistic it will be any time soon. Also not all have been situated in ideal locations. Fareham could have be thought about, and other locations don’t look like a great deal of thought has gone into it. It would be fantastic if for once, those of us who actually man and staff these possessions and isolations, actually had a say. But why apply logic on the railway.

[rodent279]

I believe that much of the WCML is not tamped, but "Stone-Blown" Stone blowers inject fine chippings below the ballast, stone blowing with chippings is equivalent to measured shovel jack and pack. Fine chippings do not grind and grate together as trains pass over and there is not the break down into water-loggged ballast dust which results in a wet bed.

 

Wet bed is a mis nomer, the way tools just bounce off you would think they were spillages of airport runway concrete

I remember my dad, who was on the CM & EE staff, back in the 1980's when there was a plague of wet spots on the southern section of the WCML, describing the mixture of gravel, ballast & "slurry", as like concrete, and wet spots as very effective concrete mixers!

 

I don't think those heavy axle hung motors of class 86 helped, in fact I suspect they probably were the root cause of the WCML being so infected with wet spots.

[Pandora]

Does anyone who deals with P-Way wet beds recall "Monica"?  What ever happened to her?  Monica was an On track Machine designed specifically  for fixing  wet beds, Monica could gobble out wet beds by going down to formation level, new ballast would be dropped into the void after Monica had done her party piece and the wet beds sites would be back to ljne speed for the next morning. 

Edited April 6, 2018 by Pandora

[Mike Storey]

Does anyone who deals with P-Way wet beds recall "Monica"?  What ever happened to her?  Monica was an On track Machine designed specifically  for fixing  wet beds, Monica could gobble out wet beds by going down to formation level, new ballast would be dropped into the void after Monica had done her party piece and the wet beds sites would be back to ljne speed for the next morning. 

 

Oh Lord - let me not be tempted to go where we all want to go with this one.........