A UK ship has arrived in Sierra Leone to help deal with the deadly Ebola outbreak in the West African country.
Royal Fleet Auxiliary Argus is carrying food, medical equipment and 32 pick-up trucks, to help keep hard-pressed Ebola treatment centres going.
Doctors, nurses and military personnel are also on board. The ship has docked in the capital, Freetown.
Ebola has killed nearly 5,000 people and infected more than 10,000 in West Africa since March.
RFA Argus set sail from Falmouth in Cornwall on 17 October and is also carrying three Royal Navy Merlin helicopters.
The BBC's Africa correspondent Andrew Harding said it would act as an offshore base for the aid effort, and described it as an "important moment".
He said there was now the "beginnings of hope" in Freetown that the giant international aid effort was beginning to get under way.
At 28,000 tonnes, the ship is one of the Royal Navy's larger support vessels, but despite having its own onboard hospital, it will not be used to directly treat anyone who has come into contact with the virus.
If any of the crew or the Royal Marines on board become infected they would be kept in isolation, and then taken to one of the clinics on the ground.
- Part of the Royal Fleet Auxiliary - which is a civilian-staffed fleet of vessels owned by the Ministry of Defence
- Principal role is as a "Primary Casualty Receiving Ship". Has an emergency department, resuscitation and surgical facilities, radiology suite including CT scanner, critical care unit, high dependency unit and general ward of around 70 beds
- Fitted with self-defence guns, with secondary role to provide specialist aviation training
- Main task of RFA ships is to supply Royal Navy warships with fuel, food, stores and ammunition
The ship also transported 35 pallets of ration packs, more than 5,000 bottles of water, and a water osmosis plant, the Royal Navy said.
Speaking from Freetown, RFA Argus commanding officer Captain David Eagles said the helicopters were a "game changer" in the fight against the disease.
"To be able to fly equipment and experts right into the heart of the areas it is needed will be a fundamental change in the way we do business. It will give the effort ashore much greater agility and velocity to deliver the mission," he told Sky News.
"For the people on-board the ship, it is just simply a case of rolling up their sleeves and getting in and contributing as best we can, and our people are very much looking forward to that."
The UK, which has pledged £205m in aid, is leading the international response to the disease in Sierra Leone, a member of the Commonwealth which won independence from Britain in 1961.
In all, the UK is deploying about 750 military personnel to help tackle Ebola in Sierra Leone, the Ministry of Defence has said.
Defence Secretary Michael Fallon has described the RFA Argus mission as a sign of the nation's "determination to lead the world's efforts to tackle the Ebola crisis".
At the scene
Andrew Harding, Africa correspondent, BBC News
The giant grey hull of the RFA Argus brushed against the dockside in Freetown and within minutes the first white pickup trucks were being swung off its upper deck and ashore by crane.
The British ship is carrying an array of useful items for the fight against Ebola - from medicine to three giant cargo helicopters that will be used to reach some of the remoter corners of Sierra Leone.
It's 14 years since the British military arrived here to help end a gruesome civil war. At the time I remember standing, with the cheering crowds, watching Royal Marines being lowered from helicopters onto the white sandy beaches nearby.
That beach-front display was a largely symbolic moment, and in the broader scheme of things, so was the Argus's arrival on Thursday - a sign that Britain's much anticipated aid operation for Sierra Leone is finally gaining momentum.
There is no cure or vaccine for Ebola, which is transmitted through sweat, blood and saliva, and has a 21-day incubation period.
An appeal for the Ebola crisis in West Africa has been launched by the Disasters Emergency Committee (DEC), and it marks the first time the committee - a group of 13 UK aid charities - has sought funds over a disease outbreak.
Appeals will be made by all the main UK broadcasters on Thursday, and the government has said it will match the first £5m of donations made by the public to the DEC appeal.
More than 13,700 people have been sickened in the Ebola outbreak, the vast majority in Liberia, Sierra Leone and Guinea.
Ebola virus disease (EVD)
- Symptoms include high fever, bleeding and central nervous system damage
- Spread by body fluids, such as blood and saliva
- Fatality rate can reach 90% - but current outbreak has mortality rate of about 70%
- No proven vaccine or cure
- Fruit bats, a delicacy for some West Africans, are considered to be virus's natural host