I'm pretty sure that I speak for all of my fellow volunteers when I say that we had no real comprehension of what to expect at the finish of London Marathon. Apparently a stampede of people would be running at us, collapsing at our feet, blocking the road, looking for photographers and searching for their bags.

Our job therefore appeared to be:
1. Encourage people not to collapse and instead to keep moving to the bag pick-up (should be easy after they've run 26 miles or so)
2. If this fails, pick people up, move them and/or call for assistance
3. Point out the photographer positions or, if this area is too busy, tell people they can't have a photo taken

If we failed, the result will be a chaotic mass of people from which escape or survival is doubtful. So no pressure then.

Sunday 25 April 2010 - the 30th London Marathon arrives. One of my neighbours is running and she is sent off by her whole family, waving flags and banners from the veranda. This is a promising sign. I invite her to say hello to me at the finish line – shouldn’t be too hard to spot each other among the 35,000 or so runners. 

'It's very nice of you to give up your Sunday for us,' she says. I hadn't really given any thought to my contribution, events are all about the athletes aren't they? Surely my job is insignificant in the scheme of things? All of a sudden I feel proud to be a volunteer.

At the Mall, I meet the rest of the usual experienced marathon finish team and take in the atmosphere of controlled mayhem. People, trolleys, vans and quad bikes are on the move in all directions with a purpose that remains a mystery to me. We get involved in the distribution of 2,500 sandwiches, medals, kit and water. (Over 2,500 people work in the finish area.)

'Where are the podiatrists?' someone asks. 'Where is the water for the medical team?' asks another.

At the finish of the mini-marathon (11-16 year olds) the sequence of post-finish procedures becomes clearer: athletes move to the ramps to have their tags removed, receive a medal, collect their goody bag via the optional photographers' positions and proceed to collect their bags.

At 10.45am and on time an impressive line of trucks arrive carrying all of the athletes’ gear from the start line on Blackheath. Our first job is to manage the crossover as the trucks barrel past nose to tail. Thirty-four trucks later we open the road again and set up the photographer positions.

I have a sneak view of the finish line, where the elite women's race has already been won by two Russians in 2:22 (Shobukhova and Abitova who finish within 19 seconds of each other!). Where is Mara? Sadly the best-placed GBR athlete finished 10th in 2:26. A procession of extremely thin women are followed by a procession of extremely thin men, interspersed with elite wheelchair athletes.

My colleague Andy spots a photo opportunity with Boris Johnson and boldly strides up to inform him that we’re from LOCOG. Boris is enthusiastic: 'LOCOG, fantastic! Go London 2012!'

Kebede (2:05:19), Mutai (2:06:23) and Garib (2:06:55) finish in the Men’s elite group as we go back to our positions in preparation for the onslaught. The fastest GBR man is Lemoncello (who finished 8th in 2:13:40).

Athletes begin to trickle through our positions. 'Blue numbers to the right, red (or green) numbers to the left', 'photos on either side', 'keep moving, keep moving'.

By 1.30pm the trickle becomes a flood. We are immersed in a throng of runners, I give up trying to remember which is my left and which is my right and start pointing instead. Exhausted and relieved the athletes need continual prompting to keep them moving.

We spontaneously start congratulating the athletes, applauding and cheering them on: 'well done!', 'congratulations!' The athletes bashfully murmur thanks and offer us ‘high fives’. A runner stops and gives me a hug. I ask an injured athlete if he’s OK. 'I’m fine,' he says, 'I've just lost a toe nail.' Another stops to talk to me about his race, I don’t have the heart to tell him to keep moving.

Several hours later, athletes exhausted to the point of delirium start filing past. One of them notices the bottle in my hand and pleads for water. I give it to him. A woman walks past me crying and obviously in pain, clutching her medal. Men with bloodstained T-shirts and groins from chaffing, people with quivering lips people of all ages, some old enough to be my grandparents, pass by.

Some runners appear with happy faces, others are kissing their medals. People who have obviously met during the run stop to shake hands or to hug before they go their separate ways. There is a sense that runners have proven something to themselves and perhaps to their families, friends and colleagues as well, by achieving a personal best or just finishing the marathon.

The costumed runners start appearing: Fred Flintstone, five guys dressed up as knights, the odd chicken or two. Two soldiers with full packs run by in a sweat. A fireman, in uniform and helmet, finishes impressively. The young man with the extra long giraffe neck is awarded a Guiness Book of Records prize for having the tallest costume.

The crush of runners reduces to a trickle again. I've lost track of time and Andy points out that we are no longer separating the 'blues' from the 'reds'. It's time for us to finish. We're tired, having been standing for over 5 hours. Somehow our discomfort pales compared to that of the runners we've seen.

Back at our cabin we grab some sandwiches and an opportunity to sit down for a debrief. I think we all now understand why no-one can adequately put into words what the job entails. There are some good suggestions but the post-event mood, as expected, is one of subdued satisfaction. Over 35,000 people have been processed.

We all receive our official volunteer Marathon 2010 medals. We then depart after 7 hours on the finish. (The regular team had been there from 6am).

On the way home on the Tube, my colleague and I, still wearing our medals and red jackets see an athlete wearing his medal. He has a soft smile on his face and nods at us. Fellow passengers begin a conversation. A woman offers him fruit which he gratefully accepts. He proudly tells us that he finished in 4 hours 15 minutes. Another runner with his family in tow joins the carriage and the conversation.

I thought strangers never speak to each other on London's public transport? Just shows you how sport can bring people together and see them at their best.

For the second time today I feel proud to be a London Marathon volunteer.