Shutterstock / Federico Texeira Shutterstock / Federico Texeira / Federico Texeira

CUSTOMERS HAVE BEEN taking to Twitter in recent days to ask why delays to services were becoming more frequent in recent days.

The answer is a perennial one: leaves on the train tracks.

It’s something that happens every year, and every year causes delays. This year is no different.

As much as “leaves on tracks” sound like a trivial occurrence that trains should be able to deal with easily, it’s actually a scientific phenomenon that railways the world over have to tackle.

A large number of wet leaves on railways can seriously affect train performance and punctuality in a number of ways – and as we’re in the thick of autumn at the moment, you can be certain to expect delays in the coming weeks.

Here’s why it’s so dangerous

“When leaves fall onto the line,” a statement from Irish Rail explains, “particularly in damp or wet weather, the rolling action of passing wheels compresses them, causing a greasy ‘mulch’ to cover the rail.

This mulch is to rails what ice is to roads. It reduces the adhesion between wheel and rail – hence the phrase ‘low rail adhesion’. The leaf mulch can also affect the operation of track circuits.

So trains must make the same journey at slower speeds, and brake much sooner before approaching a train station so that they can stop in time (much like a car on wet roads).

“If you’re a regular customer, you can probably sense the wheel ‘slipping’ on a train if you’re travelling through an area that’s affected.

This is why minor delays are more prevalent at this time of year, particularly in the early morning and early evening.

For the latest service information and news from Iarnród Éireann, keep an eye on their Twitter account.