Trains to and from Penarth have faced significant delays all day due to theft of signalling cables between Cardiff Central and Llantwit Major.

Transport for Wales have since updated passengers that all lines have now reopened but delays should still be expected on service until 5:30 pm.

Cable theft costs rail networks millions of pounds each year. The total cost to the economy – taking into account the impact of freight delays to power stations and supermarkets, and on passengers who miss appointments or have their day ruined – is even higher.

The theft of metal is a big problem for the railway as thieves target signalling cables, overhead power lines and even metal fences to sell for scrap.

Britain's rail network is designed to fail-safe, which means that when a cable is cut trains are brought to a standstill. This protects passengers but can lead to lengthy, frustrating delays while the problem is found and fixed safely.