GLASGOW Subway bosses have come under fire for the "shambolic" handling of a tunnel fault that has seen a station closed since Tuesday and services severely disrupted.

Publicly funded SPT has repeatedly declined to explain the details of an "unexpected repair", discovered in the outer circle at Cowcaddens station on Monday night.

The operator said engineers carrying out scheduled maintenance work found a problem with the lining of a wall.

Commuters arrived on Tuesday morning to chaotic scenes as Cowcaddens and Buchanan Street stations were closed and services severely disrupted.

Buchanan Street station later reopened, but Cowcaddens stayed closed all week.

Now, five days later, passengers have still not been told what caused the closure.

Sources have told us safety fears were sparked because of fallen masonry in the tunnel.

One, who was briefed on the issue by SPT when it first happened, told the Evening Times: "A piece of masonry has come off inside the tunnel at Cowcaddens. It is like having a pot hole in the tunnel. But I am surprised at how long it has taken to reopen the station."

Another source said: "I understand masonry has fallen off inside the tunnel."

SPT has repeatedly refused to confirm or deny if fallen masonry was the cause and some passengers slated bosses for their "pathetic" lack of information.

The city's SNP leader Graeme Hendry said: "SPT's management of this week's closure has been shambolic and passengers are justifiably angry and frustrated with the lack of communication.

"As a publicly funded organisation SPT has a moral duty to be open and tell the public exactly what went wrong, why it has taken so long to fix and when it will be fixed.

"With SPT having a crisis over the Subway this week it was hardly a sensible time for city council leader Gordon Matheson to sack the chairman for not being nice enough to him."

Councillor Alistair Watson, who was chairman of SPT for seven years until 2010, said the operator was facing a serious challenge to modernise the Subway while keeping the services running.

He said: "The current system is 40 years old – it is past its 'sell by' date. Like when you have an old car, it becomes less reliable. The challenge is the age of the system.

"There is a significant £300million refurbishment programme to upgrade the network and stations, but this work is being carried out while the Subway is still open.

"When the last big upgrade was carried out 40 years ago, the Subway closed for two years."

Mr Watson said that because the Glasgow Subway was a narrow gauge railway – which is rare – it made upgrades difficult.

He added: "Trying to get spare parts is a problem. The age of the system means SPT has to find bespoke manufacturers who will make to order.

"This affects everything, from the signalling to the tunnel walls and the trains."

He said the city was built on granite and clay, which can absorb water, putting pressure on the tunnels.

He added: "Because of the clay you need a good tunnel wall lining to hold the clay back. Seven years ago a system for draining and recycling the water was introduced."

In an attempt to explain the problems, SPT vice-chairman Denis McKenna said: "We recognise it has been a difficult week for passengers and are grateful for their patience.

"SPT has been concentrating on getting the system fully operational without compromising safety.

"Statements have been issued regularly to say specialist engineers are on site dealing with an unexpected repair to tunnel lining at Cowcaddens. SPT is in the final stages of that work.

"It has taken longer than expected, but keeping the Subway operational at the same time has proved an added challenge.

"SPT hopes to have the system back to normal this weekend, but we do not believe we should ever apologise for keeping passenger safety as a priority. Indeed, we believe that is our moral duty above all else."

linzi.watson@eveningtimes.co.uk