They are among the army of emergency workers who help keep visitors to Norwich's clubland safe, providing a haven for all in their familiar yellow buses. Reporter Lucy Clapham spent a night with the volunteer team on the SOS bus.

8.50pm – I arrive for my observer shift for the team briefing where I am introduced to the friendly volunteers I'll be spending the next six hours with. Tonight there's a team of eight, including two first aiders from St John Ambulance, a paramedic from the East of England Ambulance Service and two community first responders.

The SOS bus has been parking on Prince of Wales Road since 2001, providing a safe haven for visitors to the city centre every Friday and Saturday night. It was the first of its kind when it launched and since then has helped thousands of people, and created a model that has been replicated across the country. It is funded entirely by donations and comes under the umbrella of the Open Youth Trust.

The team provides a contact point to anyone whose wellbeing is threatened through illness or injury, emotional distress or an inability to get home.

As well as the large SOS bus, where clients receive first aid and advice, there is a fully-stocked medical unit where the paramedic is based and help is given for more serious incidents, and the SOS minibus, which is used on calls to collect clients and bring them back for treatment.

Shift leader Colin Crowhurst, 48, has been volunteering on the bus for nine years and said by receiving care with the SOS team, the service can save on ambulance call-outs.

But it's not just about the medical care. Colin explained: 'Part of it should be a little bit of education. We ask people: how many units have you drunk, do you know what your weekly limit is?

'About once every three months you'll get someone who's fallen asleep on the train who should have got off at Colchester. We point them in the direction of the Premier Inn and occasionally go round with them to talk to hotel staff.

'We're also used occasionally as a base for police interviews, we get bouncers pushing their earpieces in too far and chefs from takeaways who have cut themselves.

'It's all about dealing with people and if you can talk to them nicely they generally treat you the same way.'

By 10.15pm the bus has welcomed its first guests, some inquisitive American visitors. 'I wish the US had something like this, it's very conscientious of you,' one of them comments.

A cheery woman also hops on to get a pair of flip-flops, which are regularly handed out for a £2 donation to women struggling in their heels. She and her friends are so pleased with the team's help they double their donation.

12am – The city is filling up as crowds of club-goers stream past the bus on their way to Prince of Wales Road.

The team welcome their first client, a man in his 20s complaining of pain in his ribs after a fall he suffered the previous week. He is assessed by the first aiders and taken next door to the medical unit where the decision is made to take him to A&E.

Duty driver Darren Kilpatrick leaps into action and whisks him up to hospital in the minibus. The 40-year-old has been at the SOS wheel for over 10 years and said he has always liked to volunteer.

'I worked at hospital radio and used to be an instructor in the sea cadets,' he added. 'It's nice to do something worthwhile and you never know who the people are that you're helping. It might be a friend or friend of a friend. I enjoy it.'

By the time he's back from A&E, Colin has helped a man who has lost a friend and the first call of the night has come in. The bus is linked up to a radio system used by clubs, door staff and police and they are radioed to a taxi rank where a teenager has collapsed after having too much to drink.

The first aiders assess the situation as friends look on and call for further help from the first responders, who take over.

From then the calls come thick and fast and the team is out in the minibus, collecting two more revellers suffering from too much drink, while volunteers on the bus deal with several walk-ins, including a bar worker who has cut his finger and a girl with chest pains.

2am – Both the SOS bus and medical unit are full of people receiving help and it's all hands on deck as the volunteers hand out blankets, charge mobile phones so people can call parents and taxis, stitch up wounds and offer cups of water. Anyone who is picked up in the minibus or steps on board is asked the same questions: how are you getting home, where do you live and who are you out with?

As well as helping them feel better, the volunteers will rally round to get them reunited with friends, or if need be, use a mobile to call parents as the end goal is to get people off the bus and home safely, allowing the team to deal with the next client.

There's another call and it's back up to Prince of Wales Road to help the first responders with a teenage girl who has fainted.

3.20am – The team starts packing up after helping the last two clients of the night, a club-goer with a cut finger and a teenage boy feeling dizzy and cold, who is wrapped in a blanket while being checked over and given reassurance while a taxi is called.

I ask Alison Redding, pictured below, one of the St John Ambulance first aiders, if she would class tonight's shift as busy. The mum-of-two, who has volunteered on the bus for four years, feels it's been 'steady' as it can be a lot more hectic, but at the end there's always a feeling of a job done well.

Alison, 51, said: 'There's a sense of fulfilment because this is immediate care. And it's good fun, you do feel like you're making a difference if we can reduce the number of people going to A&E and help them get home to a safe place. I'm happy with the job we do.'