The £15m plans include a visitor centre in the base of the northern Fife tower.

The glass lift would whisk people 110 metres above the River Forth and give them a close up look at the iconic Scottish bridge.

Network Rail chiefs said they hoped the world famous bridge could be open to the public from 2015.

A second visitor centre on the Edinburgh side would be the starting point for guided walks to the top of the south tower.

The rail bridge, which runs across the Forth estuary between South Queensferry and North Queensferry, was built between 1883 and 1890 and is 1.5 miles long.

Network Rail said the “discreet” visitor centre under the north tower would have a “glazed ceiling to allow visitors to experience the cathedral-like scale of this awe-inspiring structure”.

David Simpson, of Network Rail Scotland, said: “While these plans are still at development stage, we believe that the options we have revealed today can be delivered without impacting the well-loved view of the bridge.

“Any infrastructure on the bridge will be less visible than the existing scaffold platform and all buildings designs will be of premium quality.”

He added: “It’s an ambitious target, but we’d love to see these plans at least partially realised by 2015 to coincide with the bridge’s 125th anniversary.”

Consultation has been launched on the plans with a dedicated website here