WHENEVER and wherever they go into action Soldiers of the 2nd Royal Welsh have to be able to trust the Gunners.

Teamwork is the watchword as on the Canadian prairies, our soldiers prepare for combat.

In the first of a two-part feature series, MIKE BUCKINGHAM joins them.

SWEATING men ram the shells into place and wait for the shouted order.

The explosion is in the middle part of the aural range - more of a thud than a crack - and smoke pours from the gun's mouth as if from a dragon's nostrils.

"If we'd had a gun like that in 1914 the First World War would have lasted a week" Warrant Officer Neil Payne says.

Sulphorous clouds of cordite from each of the four guns drift across the prairie scene, enveloping the place from where I watch.

The smell of the guns is so persistent that it enters the body and is present in digestive emissions he adds, although the choice of words is not quite so delicate.

The 155 millimetre AS90 self-propelling guns are the largest in general use by the British Army.

Their power is obliterating.

If one were parked in Newport city centre it would be able to hit a small building in Cardiff airport.

Any vehicle, armoured or otherwise unfortunate enough to be caught in its three rounds in ten seconds rate of fire would be reduced to tinsel.

Even professional gunners don't like to dwell upon what it would do to people.

Having graduated from Sandhurst, the Army's school for officers, Second Lieutenant Elwyn Clarke has been sent to 19 Regiment, Field Artillery, to learn the gunner's trade.

Before very long he will either be in charge of the death-dealing devices or else part of the team that identifies targets and calls down the fire.

The British base at Suffield in the arid prairie lands of Southern Alberta is the perfect place for practice live firing he says.

"We can and do shoot on Salisbury Plain but compared with this place anywhere in the UK is tiny."

Elwyn is rather older than the standard subaltern, 29 years old and married to Rebecca.

"I went to Monmouth Comprehensive and after that worked as an environmental management consultant in the Wye Valley getting involved with canoeing and rock-climbing and things like that."

He smiles at the suggestion that someone hitherto deeply envolved with the environment was now part of a group of people blowing it to pieces with huge guns.

The Army he says, is as careful of the environment in which it operates as it can reasonably be expected to be considering its operational commitments.

There are more shouts and three explosions in rapid succession.

Three huge barrels recoil and the tank-like gun chassis rock slightly on their tracks. Prairie dust mixed with cordite engulf the scene for a couple of minutes after which one's hearing is largely restored.

"You can just imagine what something like that does to people" 2/Lt Clarke continues.

"It's the sort of weapon you hope will be a deterrent.

"We have our duty to do but nobody can hope they will be used."

The mighty power of 19 Regiment's guns are in this instance being used to cover the advance of 2nd battalion, Royal Welsh as it rehearses for its infantry role in Afghanistan.

Not only the Army's big guns but light armour and the massive Challenger main battle tank are involved in the integrated exercise over a stretch of the Southern Canadian plains more than five times the size of the Army's traditional training grounds on Salisbury Plain and approximately equal to the area of Wales, south of Brecon.

Powerful tracked artillery was developed for use against a potential enemy coming for us across the North German Plain and is unlikely to be used in Afghanistan.

Even so says Captain Roy Pearson, training must go on.

"We are training for the future because you never know what's going to be out there.

"At the moment it seems unlikely that we will have to fight a conventional enemy but world events have a way of catching out the unwary.

"The training in Canada is as realistic as it gets without actually going to war.

"Like Helmand it's pretty bleak out there and if you can see a tree well, well done.

Take a photograph because trees aren't something you'll see much of."

With some justification the Royal Artillery considers itself among the Army's elites.

To deliver the sort of pinpoint accuracy upon which it prides itself a profound knowledge of maths and physics is required.

Even a shell the weight of a small man is affected by the wind and variations in air temperature, the potency of the charges and barrel wear can, unless properly compensated for, make for poor shooting.

In the 1914-1918 war and in the Second World War the artillery laid down 'creeping' barrages designed to keep the enemy's heads down while our own troops advanced.

If 'blue on blue' deaths are to be avoided, accuracy is at a premium.

"If we were fighting for real the artillery might be asked to put down fire within 300 yards of where we are - close enough to feel the blast". Captain Will Greswell of 2nd Royal Welsh who has Gwent soldiers under his command said.

"With that sort of stuff flying around it doesn't take a genius to work out that us infanteers are very, very interested in how the Royal Artillery does its job."