Concrete v wooden v composite v metal sleepers - How are they selected?

[Ploughman]

I recall our Supervisor saying that he had got 6 gangs of Gorillas from Manchester for the job.
My greatest recollection of the job on the night was coming over the hill from Market Weighton on 0n the A1034 and saw the whole horizon lit up from Broomfleet to Gilberdyke.
The most disheartening thing was the approach to the river bridge abut 1/2 way, with dead straight track the slight rise to the bridge hid the remaining part of the site from view.

 

[plugwash]

Price concerns will have seen the development of composite sleepers (I keep wanting to call them plastic).

It looks like at least one of the suppliers NR uses for composite sleepers is sicut, looking at their website they describe the sleepers are described as being made from "a unique blend of recycled plastics, reinforced with glass fibre.".

 

[FrontSideBus]

I knew a guy at work who built a bar area in his garden using old sleepers and at £20 a go, it soon added up.
I bet they cost a fair bit more then that when new!

 

[GRALISTAIR]

Price concerns will have seen the development of composite sleepers (I keep wanting to call them plastic). I don't know if they can be recycled.

In materials science terminology there are ceramics (includes glass, aggregate, sand, porcelain etc), metals, polymers (I prefer this term over plastics but I am biased!) and composites. These combine two sets. So steel reinforced concrete is a composite. The sleepers you refer to are a polymer matrix composite reinforced with glass fibre(a ceramic).

 

[AndrewE]

In materials science terminology there are ceramics (includes glass, aggregate, sand, porcelain etc), metals, polymers (I prefer this term over plastics but I am biased!) and composites. These combine two sets. So steel reinforced concrete is a composite. The sleepers you refer to are a polymer matrix composite reinforced with glass fibre(a ceramic).

I am surprised that you include aggregate and sand in Ceramics, as I thought that by definition they were fired, with (pottery) or without (glass) being shaped.
The other two I would have termed minerals, many being the ingredients for ceramics, e.g. kaolin or different clays - with or without a sand (silica) fraction.

 

[GRALISTAIR]

I am surprised that you include aggregate and sand in Ceramics, as I thought that by definition they were fired, with (pottery) or without (glass) being shaped.
The other two I would have termed minerals, many being the ingredients for ceramics, e.g. kaolin or different clays - with or without a sand (silica) fraction.

I can see where you are coming from and I won't get into semantics, but as you say you could say iron ore is a mineral and is converted into a metal and some ceramic (slag - which makes GGBFS (Ground Granulated Blast Furnace Slag ) - a pozzolan which goes into cement and concrete etc.

 

[Amata Lux]

Wood ties get used where lighter, more flexible stuff works better...

 

[Trainman40083]

I can see where you are coming from and I won't get into semantics, but as you say you could say iron ore is a mineral and is converted into a metal and some ceramic (slag - which makes GGBFS (Ground Granulated Blast Furnace Slag ) - a pozzolan which goes into cement and concrete etc.

Was that what replaced aggregate to make lightweight concrete troughing?

 

[GRALISTAIR]

Was that what replaced aggregate to make lightweight concrete troughing?

Not exactly though that helps a little. It tends to be modified clays or even shale - so use lightweight aggregates. I have even seen polystyrene used though I don't like it. A key trick is to use special additives that deliberately entrain air - that really helps. Also power station ash - burned coal - called Fly Ash here in the USA.

 

[Trainman40083]

Not exactly though that helps a little. It tends to be modified clays or even shale - so use lightweight aggregates. I have even seen polystyrene used though I don't like it. A key trick is to use special additives that deliberately entrain air - that really helps. Also power station ash - burned coal - called Fly Ash here in the USA.

Not so much fly ash in the UK now, given all the coal power stations have closed.

 

[FrontSideBus]

Is there a max speed and weight for any particular sleeper type?

 

[GRALISTAIR]

Not so much fly ash in the UK now, given all the coal power stations have closed.

Oh trust me - I understand. It really changes things. Also not much slag either as I understand there aren't many blast furnaces making steel either. There are often problems not fully anticipated when a change is made. This is one such example.

 

[Trainman40083]

Oh trust me - I understand. It really changes things. Also not much slag either as I understand there aren't many blast furnaces making steel either. There are often problems not fully anticipated when a change is made. This is one such example.

Well, there is still one at Scunthorpe....just

 

[GRALISTAIR]

Well, there is still one at Scunthorpe....just

Yikes. I just googled it and the reply (AI?) was....

Following the closure of the last blast furnace at Port Talbot Steelworks in Wales in September 2024, Scunthorpe Steelworks is the UK's only remaining primary steelmaking facility.

 

[Bald Rick]

Is there a max speed and weight for any particular sleeper type?

Whilst my memory might not be functioning correctly right now, I’m fairly sure you won‘t usually see any steel or timber sleepers on lines of more than 100mph.

There are exceptions, particularly through pointwork (technically bearers rather than sleepers), steel hollow sleepers for cable runs, and the occasional timber sleeper over culverts etc.

 

[Dave S 56F]

When I've travelled up the settle carlisle ex midland mainline over ribbhead on various steam tours over the years I've noticed there is alot of metal sleepers used on this line.

 

[edwin_m]

When I've travelled up the settle carlisle ex midland mainline over ribbhead on various steam tours over the years I've noticed there is alot of metal sleepers used on this line.

A lot of this was re-laid in the Railtrack era, aiming to cut maintenance costs. I believe the Up line was more extensively replaced as this carried the heavy loaded coal trains (that went well didn't it...).

 

[1955LR]

There are exceptions, particularly through pointwork (technically bearers rather than sleepers), steel hollow sleepers for cable runs, and the occasional timber sleeper over culverts etc.

I remember a few years ago the Ledbury - Hereford line was closed when track over a culvert was found to be defective. There was a statement made that the delay in reopening was due to arrangeing supply of special size wooden sleepers