When the worst humanitarian disaster in 200 years struck the poorest nation in the western hemisphere on Tuesday last week, Paul Sherlock of Oxfam was the man in charge of mobilising help — fast.

Initial aid — including heavy water tanks, pipes, latrines and other sanitation equipment from Oxfam’s emergency depot in Bicester — was flown out to Santo Domingo on Tuesday from East Midlands airport. And even before that, on Saturday, an emergency team of six Oxfam assessors left Heathrow for Haiti.

Following the Saturday flight, another 30 tonnes of equipment left the UK on Tuesday and another 50 tonnes will leave tomorrow for the stricken Caribbean republic.

Among the estimated 100,000 to die in the earthquake of Tuesday, January 12 were two Oxfam workers.

One, business manager Amedee Marescot, who had worked for the charity for 13 years and had often visited Oxfam’s headquarters in Cowley, was killed when part of the charity’s office in Port-au-Prince collapsed.

And the charity’s country director, Yolette Etienne, who came into work at 8.30am on Thursday, had earlier that morning buried the body of her mother in the backyard of her home.

Most of Oxfam’s staff had their homes damaged or destroyed and are sleeping outside like the rest of the Haitian population.

Mr Sherlock said: “It happened at about 5pm English time. I was out in my car and heard it on the radio. The response mechanisnm had to swing into action straight away. We had to put a team of assessors on immediate standby to leave. Of course, it is part of their contract with Oxfam to be ready at all times to leave for anywhere in the world at any time.”

Mr Sherlock, 63, an Oxfam veteran who has worked for the organisation for 35 years and is now its senior humanitarian representative, added that the Haiti disaster was different to others in his experience because the whole infrastructure of government has collapsed.

He said: “Obviously, communications were a problem from the start, but there was a United Nations office from which staff could telephone out.”

He added: “Logistics was the other obvious problem. There is a much publicised logjam at Port-au-Prince airport, where aid is being held up, but we sent our equipment into Santo Domingo in the next-door Dominican Republic. It then made its way to Port-au-Prince, an 18-hour drive away.

“We are not shouting, yet, as are some other agencies, including Medecins sans Frontiers, about the US administration of the airport. We don’t think that is the right option. We must be realistic and look at the situation as it is.

“Our advantage was that we already have an office on the ground in Haiti, employing nearly 100 people. We were able therefore to distribute some water and sanitation equipment straight away. We had some left over from our disaster relief programme last year which went into operation after a cyclone hit Haiti.”

The charity salvaged that equipment from its warehouse, which was destroyed in the quake along with much of the £75,000 worth of equipment stored there.

How long Oxfam will refrain from shouting is a moot point, though.

On Tuesday, Oxfam’s spokesman in Haiti, Louis Balanger, wrote in his blog: “Unfortunately, today Oxfam had to halt its water distribution because of the lack of fuel in Port-au-Prince.”

He added this was a real concern, not only because it stopped transport, but also because it threatened communications as, in his words, “everything is working on generators right now”.

Despite such reports of a breakdown in organisation, Oxfam says the rate of giving in this disaster has been outstanding.

On Tuesday, a week after the quake, £25m had been donated in the UK to the Disasters Emergency Committee (DEC).

The DEC is a group of 15 leading UK charities, including Oxfam, which have grouped together to streamline donation collecting.

The money given is divided up according to each charity’s capacity to deliver what is wanted, where it is wanted, and when it is wanted. At present Oxfam receives 22 per cent.

Spokesman Ian Bray said: “Our fundraising policy as a general rule is to work to a ratio of collecting £5 for every £1 we invest.

“But in an emergency like this, that ratio goes out the window: we receive far more. In fact, we spend nothing on advertising, since the TV companies offer us free air time, and credit card companies waive their fees to donors too.”

He added that the dozen people employed at Oxfam’s Bicester warehouse had worked tirelessly over the weekend and in the evenings to load the tonnes of sanitation equipment ready for airlift.

Mr Sherlock added that Oxfam’s particular area of expertise in the coming weeks will be to provide water sanitation and hygiene equipment which, according to the World Health Organisation, is the most vital role of all to preserve life, even more vital than burying the dead.

He said: “Everyone is sleeping outside at the moment and luckily the weather is dry. The next move will be to move people off the streets and into camps. But the risk of disease is huge. Latrines are needed desperately.”

He himself was seconded in recent years to the United Nations to oversee the formation of a cluster of charities, called WASH (Water and Sanitation Hygiene) and so is an expert in this area of operations.

The UN is worried that law and order will break down in the scramble for food and water, and is providing peacekeepers, but against this background Oxfam simply tries to play its part in providing whatever is needed.

The poignant message from Yolette Etienne, whose mother died last week, is this: “Many of my staff here have lost their homes, and some have had family losses.

“Two Oxfam members of staff were killed when the quake struck and I lost my own mother.

“But we are still here working. I told my staff that we have no choice, no other option but to work and to work harder since we have the privilege of still being here and we can help people to overcome their desperation.”

• To donate, call 0370 60 60 900 or visit www.dec.org.uk.