Our Changing Rail and Sleepers...

[matthewmacleod]

Are metal sleepers still used or was that just a Railtrack thing?

I think Airdrie to Bathgate was all new steel too.

 

[LesF]

Rails have increased in weight per yard from 109 pounds per yard in the 70s to 56 or 60kg /m today and concrete sleepers have increased by over 20kg each in that time, so your observations are without substance. Rail mass has very little effect on ride quality.

In answer to Elecman, the 109lb/yd rail used from the 1960's was the flat-bottom rail pioneered in USA, while for low-speed track the norm was 95lb/yd bullhead rail. Further, the greater dispersion of the metal from the neutral axis in flat-bottom rail gives more bending resistance than an equal amount of metal in a squat rail section. But a greater influence on ride quality is settlement of the sleepers. Sleepers do not flex much - for a concrete sleeper a large deflection would lead to early failure due to cracking, water penetration and rust of the reinforcement. A much greater factor is settlement of the sleeper each time an axle passes over. So stiffness of the sleeper is less important than the area of ground contact; if you double the contact area you halve the ground pressure. In slab track you treble the contact area, so less depth of ballast is needed. That's why slab track is preferred for tunnels, where construction height is critical.
The increased rail traffic due to passenger demand makes closure for maintenance more problematic, so track needing less maintenance is to be preferred.

 

[Steptoe]

Interesting thread though my experience in changing sleepers was manually on a preserved line.

However, last week visiting the Ravensglass & Eskdale line, I was interested to note that they have a section resleepered in plastic. The guard said that these were sourced from standard gauge size cut into three, however they then found that their supplier reduced the cost of wooden sleepers to be more competitive so are no longer laying plastic.

Of course I'm now wondering if the full size plastic ones have been used anywhere on the main line? Obviously I couldn't look underneath them but they were made of recycled plastic and were the same dimensions as wood and must have been solid as the rail plate was attached with a conventional chair screw.

 

[DarloRich]

not aware of plastic sleepers having been used on the main line.

 

[superkev]

It's not only rail and sleepers that have changed over the years:
Looking at some flat bottomed track at the Great Central railway the other week at least 3 different fixings the most common being the early 3 spike variety. Not sure how many they where before the now almost universal Pandol clips.
K

 

[Ploughman]

Off the top of my head, these are or were in common use.
Macbeth, BR1, AD, SHC, Mills, KT, Pandrol, Pandrol e, Fastclip.

Of these we have examples of all these except the Macbeth and BR1 spikes in the ground on the NYMR,
KT being the rarest but they do exist.
Pandrol of both types being the most common.

 

[mcmad]

Ahh, the universal pandrol clip.... There must be nearly 2 dozen variations by now to the point that pandrol have to publish a booklet describing them and what is compatible with what. Theres only 1 type of fast clip thou (so far)!

 

[Joseph_Locke]

Ahh, the universal pandrol clip.... There must be nearly 2 dozen variations by now to the point that pandrol have to publish a booklet describing them and what is compatible with what. Theres only 1 type of fast clip thou (so far)!

Ahem, FC and FE ...