Rail101 - Which type of rail is best?

A question which I'm sometimes asked is which rail is the best. I'll be upfront with a clear answer...

"There is no 'best' rail"

I should probably add to that "for every situation" to be complete, although I'm aware some of my competitors may disagree.

I am a big advocate of using "the right rail in the right place", and as we know not all track is the same. The right rail for a high speed tangent/straight isn't likely the same as on a heavy freight sharp curve. You wouldn't expect your motorway/highway/autoroute to be built the same as a little country road, so why would a railway be any different? You wouldn't buy a big off-road 4x4 just for the shopping and the school run would you....

...Well ok perhaps that isn't the best example but the absurdity of that choice I hope isn't lost on everyone.

Another important factor aside from the actual performance of rail is the concept of "best" varies significantly with the role the person performs in the railway.

• Someone in procurement would usually prefer something cheap, available now and performs the same from every supplier.
• An installer wants something that is quick and simple to install.
• A maintainer wants something that is predictable and simple to maintain - or ideally no maintenance at all!
• Network owners / governments are generally looking for the minimum cost over a certain time period, (The time periods they look at can vary massively - anywhere from 5 years to 50 years are common).

So instead of trying to tell you this rail is best or that one is, I'll simply advise what works best at resisting some common issues seen on the railway and give you a flavour of their relative performance against some common grades. I'll refer to British Steel grades throughout as that is what I know best, but other manufacturers often have similar alternatives.

The table below tries to simplify things depending on which degradation type limits the useful life of your rail

In the example above if you are looking to improve the wear resistance of R260 grade rails then you might look at R350HT. If you need higher wear resistance still, then you might look at Maximum Head Hardness (MHH) range or other alternatives such as R400HT which offers the highest levels of wear resistance. A a rough guide moving from R260 --> R350HT gives about a 3 times improvement in wear resistance, and moving up to the MHH range typically doubles the wear performance yet again.

Above - A little animation of the rail wear process in action

Now some may assume that the MHH range of rails is then the "best" and my initial statement is wrong. If you are ONLY considering wear of the rail then that would be correct, however in real life there is also contact fatigue to consider too. Without suitable grinding regimes in place or suitable levels of wear from traffic, then contact fatigue may limit the life of your rails long before they become worn out. I'll not go through each grade in detail as that would be quite a dull article - but hopefully you can see which excels at what and our technical teams are there to offer advice where alternatives are being considered.

There are also some unique environmental challenges on our railways and so its only fair to cover some of the rail products that address some of these unique challenges too, whether it is rail corrosion or oxidation causing problems with safety or signalling or even noise reduction to help the railway be a good neighbour - there are some unique solutions to some specific track issues.

If rail corrosion is limiting the life of the rail - then there is no use installing rails that wear less - as the corrosion limits the useful life. However corrosion protected rails such as Zinoco can help stop your rails going rotten. Life extensions of 5-10 times are typical delivering longer and safer rail life.

Above: Rotten rails removed from operational track aged 3 months to 10 years

Likewise an oxidised rail head can prevent track circuit signalling working reliably - which is where Sogenox finds its niche. This is a simple concept - A rail with a stainless steel crown to prevent oxidation of the surface and keep signal systems working correctly with no speed limits and no in-track welding required.

Above: Sogenox rail with stainless rail crown visible

I would hope the benefits of reducing rail noise particularly in sensitive areas using SilentTrack or other rail dampers are fairly self explanatory. If you need more info on any of these then drop me a line or if you are feeling shy then tap their name into google first.

The products above all have extremely useful attributes to tackle specific track troubles. But that doesn't make one type the "best" for everything - Intelligent rail/grade selection is needed to provide the optimum returns.

"Use the right rail in the right place"

If you like what you've read then follow me for more #rail related articles, and if you'd like to learn more about the basics of rail then follow the #rail101 tag for more that I've written. You can find a summary of them here.

If you need advice on which is the right rail for your track troubles then drop me a line or better still a comment below and I'll see if I can help.

What are your track troubles? Let's see if we can solve them.