Slate waste - could it ever be viable freight?

[Meerkat]

Reasonable queries descending into crayon fantasy.....
The increasing cost and demand for aggregates lead to a plan a while back for slate waste to be brought down the Conway valley but I believe it got canned due to vibration issues for housing very close to the line.
First question is whether removal would be allowed - would taking away all the slate waste and regreening (bit like the Cornish Alps have gone) be a good thing for the locals or do they see the waste as part of the charm now?
Secondly could the Conway Valley route ever be viable - would the trains now be more neighbour friendly?
Thirdly, and most desperate.....could the narrow gauge tourist lines ever be used for freight again? Crayons going for exchange at Minfford by the quarry, or a new freight/tourist line from Llanberis to Caernarfon......yeah I know, it’s slate not gold!

 

[Dr_Paul]

It all depends whether there is a big demand for slate waste. There is some demand: for example, I know that a quarry near Arthog (west of Dolgellau) has had its waste tips processed and the crushed rock removed, and I'm pretty sure that this has happened elsewhere. But whether the tips at Blaenau Ffestiniog would be processed I have no idea: even if they were there would have to be a very large demand for the material for it to be removed by rail. Were there such a demand, the tips at Blaenau would be ideal, as they are close to the railway and there would be space for a loading depot. I very much doubt that it would be worth rebuilding the lines from Llanberis and Bethesda; were waste to be moved from there in any large quantity, it would be most conveniently moved by road to a convenient railway depot near Bangor.

 

[6Gman]

I'd be disappointed to see too much of the waste removed - part of Blaenau's heritage.
My understanding was that the main complainant(s) were in Colwyn Bay rather than the valley. (Wonder what he'd have made of smelly cattle trains past his balcony in the past ... ? )
Would love to see a 66 on hoppers skirting the riverside at Tal y Cafn !

 

[gazthomas]

I'd be disappointed to see too much of the waste removed - part of Blaenau's heritage.
My understanding was that the main complainant(s) were in Colwyn Bay rather than the valley. (Wonder what he'd have made of smelly cattle trains past his balcony in the past ... ? )
Would love to see a 66 on hoppers skirting the riverside at Tal y Cafn !

That is amazing if true, the classic railways come first scenario!

 

[Dr_Paul]

I agree that the removal of waste tips from Blaenau would spoil the town's unique atmosphere, although they are closer to a railway than in any other place in North Wales and would probably be the first choice were large-scale reprocessing to become a reality.

I have an idea that one tip, next to the FR where there is now an empty patch, was removed in the 1980s or thereabouts, but I don't know for sure when or why it was done. As it is, slate waste tips are pretty stable, unlike coal waste tips, which have a tendency to slip if wet. The disaster at Aberfan was the result of coal waste being dumped on a spring, which destabilised the tip with the awful results we know about; if this happened with slate waste, the water would have trickled through without destabilising the tip.

 

[AndrewE]

Judging by the debris around the foot of many of them the tips aren't particularly stable anyway! I am sure that, while they may be part of the current scene in Blaenau, the employment that would be generated by an ongoing removal programme would be welcome in the area, even if it was only a dozen jobs.
There is a continuing demand for aggregate or fill in the UK and a proper aggregate levy would ensure that these secondary materials got re-used - rather than ripping up more countryside for new or extended quarries.
If the railways need reinforcing or re-connecting to service it then that is a secondary benefit, especially when it opens the option for improving passenger services on the back of the freight scheme.

 

[ChiefPlanner]

All about economics surely ? - where is the nearest large market for aggregate to BF ? - probably the North West , the South East wold happily take crushed slate but it is a hefty rail haul over congested routes.

The waste would need (I assume) to be crushed , probably near the loading site , which might in itself cause protests from the locals , as slate waste , railway and housing are rather congruous.

One option would be to move it in bulk to a port location and ship by sea to say Angerstein Wharf or the Isle of Grain and distribute from there , but this would cause double handling and double mode. I cannot think of any suitable rail /sea ports now that Holyhead is a roll on off port and Deganwy is a housing estate !

Whilst waste has been used for general projects (the Gloucester Road Junctions were assisted by Kent mine stone in the 1980's) , I may be wrong but longer hauls of stone tend to be the better quality types - such as gritstone from West Wales to the South East. Crushed Mendip stone has a haul of about 90 miles and in very bulky trains which assists economics.

A good few years ago - the Ffestiniog did a discussion on a "plan" to carry this stuff to Minfford , which assumed - or required - virtually 24 hour operation and the wear and tear would have almost destroyed the infrastructure.

 

[Dr_Paul]

The waste would need (I assume) to be crushed , probably near the loading site , which might in itself cause protests from the locals , as slate waste , railway and housing are rather congruous...

A good few years ago - the Ffestiniog did a discussion on a "plan" to carry this stuff to Minfford , which assumed - or required - virtually 24 hour operation and the wear and tear would have almost destroyed the infrastructure.

I reckon there's room for a crushing plant with a siding between the tunnel mouth and Blaenau station, and it's some way from the bulk of the town's houses.

I didn't know that about the FR's investigations. Even the large bogie wagons on the WHR wouldn't take that much waste, probably no more than the average tipper lorry. I think that the waste would have to go straight from the crusher into large standard-gauge wagons.

 

[ChiefPlanner]

I reckon there's room for a crushing plant with a siding between the tunnel mouth and Blaenau station, and it's some way from the bulk of the town's houses.

I didn't know that about the FR's investigations. Even the large bogie wagons on the WHR wouldn't take that much waste, probably no more than the average tipper lorry. I think that the waste would have to go straight from the crusher into large standard-gauge wagons.

I think the FR's investigations were one of the whimsical discusions they have from time to time (a good while ago) in their excellent magazine.

All academic anyway , as apart from the economics (discussed previously) , the Conwy Valley line is not exactly a 100% guaranteed all weather route.....

 

[PaxVobiscum]

Perhaps if some of the slate waste was used to improve the Conwy Valley line itself first...

 

[ChiefPlanner]

Perhaps if some of the slate waste was used to improve the Conwy Valley line itself first...

If anyone needs several millions tons of weathered stone , there is someone in BF who can help. I do wonder who actually owns it ........

 

[Llanigraham]

From my experience slate waste is not a good product to be used as aggregate due to the way it readily splits and doesn't form "lumps" like granite or limestone.

 

[AndrewE]

From my experience slate waste is not a good product to be used as aggregate due to the way it readily splits and doesn't form "lumps" like granite or limestone.

I agree it's probably not good in concrete, but I suspect that for "fill" where you want it to knit together as it is compacted it may be one of the best materials.
I remember a highways engineer insisting that MOT type 2 aggregate was a mix of sizes so that it did knit together but still remained porous enough that water could drain through it. It seemed a bit improbable to me.