By Julian O'Neill BBC News correspondent in Belfast

Fighting sleep can be as tough as fighting fires for Goddess teams on nightwatch at Northern Ireland's busiest emergency station in north Belfast.

The six crews at Girdwood Barracks have tackled 17 blazes in five days and envy the shift patterns and wages of the striking firefighters they have replaced.

Many soldiers on the overnight shift earn about half the �21,000 basic salary of the firefighters.

When the dispute started the Army was concerned the Goddess units could be attacked in nationalist areas - a few incidents aside, that has not happened

"Send them to Afghanistan for six months and then they'll know what work is," snaps one soldier trying to catch some rest.

About 500 Army and RAF personnel trained in firefighting techniques are in to Northern Ireland to do the jobs of the 1,700 men and women taking part in the industrial action.

Replacing 110 red fire engines are 32 Goddesses, which uniquely in Northern Ireland, have been painted yellow to distinguish them from other military vehicles on regular security duties.

Soldiers call them "custard creams".

'Telephone rings'

When the dispute started, the Army was concerned the Goddess units could be attacked in nationalist areas.

A few incidents aside, that has not happened.

Indeed, most at Girdwood Barracks report warmer relations with locals than usual.

"A man came out of his house and give me a cup of tea," says Private Darren Webber.

"He said it was the first time he'd made a soldier tea in 26 years. People are letting us get on with the job."

We were at this house only last night and a lot of what we've been to is a nuisance really but we have to deal with it regardless

Corporal Alex Coker

The sixth night of the strike turned out to be the quietest.

Eight hours after their last call, the telephone rings to dispatch a unit in response to a 999 call.

The Goddess makes slow progress, travelling at less than 40mph, but has only a mile to go.

Part of an unoccupied house in a derelict street in the Shankill area has been set on fire and poses little challenge.

Water is flowing from the hose in less than a minute and soon the small blaze is under control.

"The team coped well as we've had plenty of practice," says Corporal Alex Coker.

"We were at this house only last night and a lot of what we've been to is a nuisance really, but we have to deal with it regardless."

Accommodation block

As the crew dampens down the flames, soldiers with rifles slung across their shoulders guard the streets.

The last time the Army had to take up hoses in a national fire dispute was in 1977 when terrorist campaigns in Northern Ireland were at their height.

Times may have changed with ceasefires, but a unique feature of the strike in this corner of the country is the cover accorded Goddess units.

These guys are on duty pretty much 24-7 but we're proud of what we've done so far

Senior officer

The Girdwood crews are housed in a wind-swept warehouse which has been turned into an accommodation block during the strike.

The last time it was used for this purpose was during the major security operation surrounding the loyalist picket of the Holy Cross Catholic Girls' Primary School.

The block has two showers between 80 personnel but the camaraderie makes up for any discomfort.

"The rotation of crews is difficult," says a senior officer.

"These guys are on duty pretty much 24-7 but we're proud of what we've done so far. We're even getting to the scenes of most fires in a response time of 20 minutes."

Their job is being made less demanding by a fall in the number of hoax calls.

During the early stages of the first, 48-hour strike over half the 999 calls in Northern Ireland were hoaxes but that figure has dropped to 20%.

But just when things are looking up comes another call and the possibility of two more strikes before Christmas.