The superhuman feat of two Scottish climbers 50 years ago, climbing Ben Nevis six times in seven days, will be celebrated this month at a film festival

IN FEBRUARY 1960, Scottish climbers Jimmy Marshall and Robin Smith made history when they completed six first ascents on Ben Nevis in seven days, also romping up the intimidating Point Five Gully in record time. Their achievements shook the climbing world, and they still resonate today.

• Smith's Route

Later this month, as part of the Fort William Mountain Film Festival, there will be a special commemorative event to mark the 50th anniversary of their legendary week on the Ben.

Sadly, Smith won't be around to bask in the adulation – he was killed in a climbing accident in Russia in 1962 – but Marshall, now about to enter his ninth decade, will be on hand to speak for them both.

"We enjoyed every moment we were climbing that week," he says. "The conditions were splendid. There was a fair amount of surface snow here and there, but most of it was good frozen nv. It was just terrific. A real buzz."

The Fort William tribute is split into two parts. First, leading contemporary climbers Dave MacLeod and Andy Turner will attempt to repeat Marshall and Smith's feat, tackling the same seven ascents in the same one-week window (6-13 February), with award-winning film-maker Paul Diffley on hand to record their efforts.

Then, on 14 February – "Jimmy Marshall Night" – Diffley will screen edited highlights of the climbs at the Nevis Centre Festival Theatre, and MacLeod and Turner will compare notes and swap anecdotes with Marshall.

From the remove of the 21st century, it's difficult to put Marshall and Smith's climbs into perspective, to grasp the sheer magnitude of what they accomplished. One option is to refer to the Scottish Winter Grading system drawn up by the Scottish Mountaineering Club.

The routes the duo pioneered – The Great Chimney, Minus Three Gully, Smith's Route, Observatory Buttress, Piggot's Route and Orion Direct – are all either grade IV or V climbs, meaning they contain long sections of ice angled at 60-70 degrees and some shorter vertical sections.

Somehow, though, the bald statistics aren't enough. To appreciate fully what made Smith and Marshall's climbs so special, you have to compare the equipment and techniques they were using with those employed today.

When MacLeod and Turner set off on the first of their tribute climbs on 6 February, they will be encased in the latest waterproof, breathable gear and wearing lightweight climbing helmets. They will carry a range of protection, including modern ice screws, so if they fall they should not fall far. Most importantly, perhaps, they will climb the steepest pitches with an ice axe in each hand and wearing crampons with forward-pointing spikes on their feet.

By contrast, Marshall and Smith wore whatever clothing they could get their hands on. ("I had a very good ex-American army thing," remembers Marshall. "It had a wolverine fur collar that didn't freeze and it had no pockets whatsoever – you just put that on over you and that was it, on you went.") The old-fashioned hammer-in pegs they used for protection were nowhere near as secure as the modern screw-in equivalents, and, crucially, they didn't have forward-facing crampons and carried only one ice axe each. This meant they had to use an energy-sapping and now obsolete climbing technique – step-cutting – to progress up the almost sheer walls of ice.

"Most of these climbs meant going up narrow chimneys or gullies," says Marshall, "so you would brace and whack away at the ice with two hands. I very rarely used one hand. If you were going up an open slope you'd use one hand, but when you're climbing a real ice gully you're doing two-handed cutting. It's very easy to topple backwards if you've not got any security, so you become very good at balancing.

"You'd cut a step where you could get a decent balancing foot and then from there you'd cut the next series, climb up them and then start again. It was a process of limited jumps."

Step-cutting may be a historical curiosity today, but in 1960 it was the accepted way of ascending steep ice. Marshall is far too modest to say so, but at the height of his powers he was world-class at it.

In Who's Who in British Climbing, Colin Wells writes: "The fact (Marshall and Smith] achieved (their six first ascents on Ben Nevis] by cutting steps up the snow and ice appears, from the remove of the 21st century, to be almost unbelievable. Marshall's skill was such that he could lead routes almost faster than some of his talented seconds could follow."

• Film-make Paul Diffley

Does Marshall look at winter climbers today, with their fancy ice screws and Kevlar ice axes, and think they have it easy?

"No, I don't think so," he says, "because they're taking it to further extremes. Obviously these guys are very fit and very competent, and lots of them are professional guides now – I've got a lot of respect for them. But I find it appalling when I see people who are not as good as them sort of crawling up with two axes, on their hands and knees, virtually. There's no sense of balance or anything. I find that an eyesore."

Dave MacLeod obviously has balance, and plenty of it. What does Marshall think of Turner and him attempting to recreate his iconic climbs? "Well," he says, with a sigh, "they must be a bit bored to have to come and do things like that, you know. But he is sincere in his love of historical things."

MacLeod – not just one of the best all-round climbers in Scotland today, but one of the best in the world – is clearly in awe of Marshall's achievements. As far as he's concerned, Marshall and Smith weren't just years ahead of their time, they were decades ahead.

"Point Five Gully had been done about two or three seasons earlier," he says, "but that was done over a period of days. The first people to do it would do a pitch one day, then come back down to the hut and leave all the ropes in place. Then they would come back the next day and climb another pitch. It was a major operation for them. Smith and Marshall went up it in about six hours.

"What they were doing was at the absolute limit of what was possible in their day. If any other team had done just one of those routes it would have been a really big deal, but they came along and did all of them in a week. It wasn't until a couple of decades after that until climbers started to come close to the level of skill and fitness they had."

For all that he clearly reveres their achievements, MacLeod shouldn't find Marshall and Smith's grade IV and V climbs too taxing. In 2008, he made a first ascent of a grade XI route on Ben Nevis called Don't Die of Ignorance. He has also established the hardest traditional mixed climbing route in the world, The Hurting, in Coire an t-Sneachda in the Cairngorms, another grade XI.

"I'll not be having sleepless nights before doing any one of these," he says. "Really, the challenge of doing it is more to do with fitness. It's going to be really arduous to do all these routes back to back, because they're big climbs; they're the closest thing we've (in Scotland] got to Alpine face routes."

If anyone is going to be pushing the limits of what's possible over the course of these ascents, it will probably be film-maker Paul Diffley. Usually when he shoots climbing films, Diffley is able to find a relatively safe vantage point from which to capture the action. Some of the Ben Nevis routes are so long that he will have to climb alongside MacLeod and Turner, holding his camera in one hand and hanging on for dear life with the other.

"This is definitely one of the most challenging film projects I've undertaken," he says. "One of the things I get asked a lot about my films is, 'Do you have to climb the mountain at the same time?' And obviously the answer is usually, 'No, you go up the easy way up the back and then abseil in.' But in this case I will have to be climbing at the same time on similar routes. Some of the routes are four or five pitches long, so the only way for me to get in position to film is going to be to climb alongside the climbers. I'm going to have a mountain guide lead my route for me, and I'm going to second him with my camera and then film the action – hopefully. I'll also have a second camera person with me as well, Guy Heaton. If the weather's clear, he'll be filming from a tripod to get the long shot and I'll be doing the close-up stuff."

The weather might not be clear every day from 6-13 February; in fact it's Scotland, so it probably won't. It might be foggy, there might be heavy snowfall, increasing the avalanche risk, or there might be howling, gale-force winds. Even with all the wonders of modern climbing technology at their disposal, MacLeod, Diffley and co can't be certain of success – which only adds to the mystique of Marshall and Smith's original achievement.

• Jimmy Marshall Night – The Architect of Modern Scottish Climbing is at the Nevis Centre Festival Theatre, Fort William, on 14 February. The Fort William Mountain Film Festival runs from 11-15 February. For more information, or to book tickets, tel. [phone] or visit www.mountainfestival.co.uk