A shotblaster cried as he told an inquiry he saw a workmate fall to his death through the missing floor of an abandoned walkway on the Forth Bridge.

Mick Muir was working for sub-contractors Thyssen Krup Palmers applying a special coating designed to put an end to the "never-ending task" of painting the 120-year-old landmark.

The inquiry heard that Mr Muir, 43, together with chargehand Joe McGinley, 56, and the man who died, Robert MacDonald, 52, made up "a close knit team" and were on the night shift as usual when the accident occurred, on January 2, 2010.

Mr MacDonald, from Harthill, Lanarkshire, fell 150ft from the abandoned walkway before landing on scaffolding, after taking an unauthorised shortcut to avoid "a sore climb" up 19 consecutive ladders.

Giving evidence on the second day of a fatal accident inquiry, at Dunfermline Sheriff Court, Mr Muir said that all three of them had agreed to take the short cut, which had been suggested by Mr McGinley.

The men should have descended by hoist from a "bothy" near the top of the centre cantilever of the bridge, where their tools were stored, then traversed a level walkway at deck height before climbing the 19 ladders.

Instead they agreed to clamber over a barrier and use the abandoned walkway, which led down a sloping cross-member of the bridge towards the area which had been sheeted off for them to work in.

The inquiry heard that at one point the "unauthorised" route involved a clamber over the very top of a bridge "main leg", where the handrails had completed rotted away.

Further along, though the team did not know it, two sections of floor grating were completely missing.

Clearly distressed, Mr Muir said: "I knew it was wrong but I went with it. I don't know why I agreed."

Mr Muir, who said he had worked on the bridge for seven years before the accident, said he felt "apprehensive" as he and Mr MacDonald helped each other over the main leg - a manoeuvre which left them exposed at the very top of the structure.

He said that after making their way over the barrier, he and Mr MacDonald continued along the route, which Mr McGinley had already taken.

Mr Muir said that he was slower at moving down the walkway than the other men, and a gap of around 40ft formed between him and Mr MacDonald.

Wiping tears away he said: "Rab (Mr MacDonald) was about 30 or 40ft in front of me. I was just slower. I could see that Rab was using the hand rails and he was carrying his bag in front of him.

"Then I just saw the black bag go up in the air. I knew when the bag went up he had just dropped and fallen."

He said: "I shouted to Joe, 'Rab's fell - he is dead'."

Mr Muir told the court he made his way back up the walkway to where he collected his gear at the start, before making his way off the bridge.

He said: "I was just in a state, I couldn't walk."

When asked if he would have taken the shortcut had he known about the missing gratings he replied: "No way."

On Monday the inquiry heard that Mr McGinley, who had gone ahead, had got over the gap in the walkway by edging across with his feet placed sideways on the empty angle-iron which had supported the missing grating.

Then he had kicked a hole in plastic sheeting surrounding the work area in order to get access from the unauthorised approach route.

Mr McGinley, who was also visibly upset, said he thought his co workers would see the missing grating, just as he had.

He said that at the time he had not considered the dangers of the side-stepping over the angle-iron in the pitch darkness. Earlier, he agreed that workers on the bridge were warned not to compromise safety by taking short cuts.

Nearly 100 men died during the construction of the bridge, which opened in 1890. The last fatality on the bridge before Mr MacDonald was in 1992.

The inquiry, before Sheriff Ian Dubar, at Dunfermline Sheriff Court, continues.