O NE of the most popular myths about Cambodian rail travel has it that passengers traveling on the two "mine clearing" flat bed cars pushed in front of the locomotive ride free of charge.

Not so, they take the risk and they pay for the ride - 1,500 riel to be precise.

Two unusual engineering modifications to the 1960s French-built Alsthom locomotive, indicate rail travel in Cambodia is not an occasion without peril.

The front of the cramped cab is sheeted with inch-thick steel plate with two visors cut for visibility.

Steel fashioned from railway iron have been welded into a device not unlike the "cow catchers" bolted onto steam trains in Wild West films.

The heavy-duty glass windshield is punctured by a bullet hole while the steel cab doors and interior paneling are also scarred by recent shrapnel.

For the train crews and accompanying railway militia the biggest security threat is posed by marauding gangs of Khmer Rouge guerrillas, but it is not unknown for renegade bands of poorly paid, undisciplined government soldiers and police to be involved.

"Each time they attack, I crouch down," said Em Op, 56, chief engineer on a Sihanoukville-bound train earlier this month.

Op is a survivor of more than a dozen train ambushes dating back to the early 80s when he drove steam locomotives.

"They were terrible - when rockets hit the firewood behind the engine it was the crew who suffered most. It showered spinsters into the cab and the firewood fell on us," he said.

Trained in the 80s to drive steam trains, Op said he had only seven friends left from his original class.

"The Khmer Rouge killed most of them during the Pol Pot time, then one of my oldest friends died in an ambush in 1984," he said.

After leaving Pochentong, the line spears south to Takeo passing through lush green paddy fields surrounded by tall sugar palm trees.

In the fields, farmers guide their ox-pulled wooden ploughs churning sods of earth ready for planting. Children frolic in fresh flowing streams, swollen by recent monsoon rains.

Shimmering in the distance, the red terracotta tiles of a Buddhist pagoda, completes a scene of rural idyllic splendor.

The Kampot line arguably winds through some of the most scenic countryside in Cambodia yet it can be some of the most dangerous.

On July 26 Khmer Rouge guerrillas raided a Sihanoukville-bound train, leaving 13 people killed and three Westerners hostage.

"It was an average attack," said Op, adding that he was unaware he was carrying three foreigners.

"The day before the elections - that was worst. They [Khmer Rouge] were waiting for us on both sides of the railway and they used rockets to attack us.

"More than 30 people were killed," he said. Yet despite the attacks, the number of passengers who travel on the trains has increased Op said.

"These are poor people - they use the train to transport chickens, eggs and vegetables," he said. The second engineer estimated more than 350 people were traveling on the train.

For Cambodia's impoverished rural dwellers the train is the cheapest and most reliable service for them to take their goods to market.

About 26 train militia travel on board. For the most part they doze in their hammocks but when the train approaches Kompong Trach they became alert and shouldered their weapons and clip on their ammunition pouches. Several climbed onto the carriage roofs.

"Each time the Khmer Rouge attack a train we've never been able to defend our position.

"The [mine] explosions cause many of us to lose our nerve. Only very few times have we been able to defend the train," said Ouk Gam Ocun, 32, armed with an AK-47, his tunic pockets full of grenades.

Earning on average a salary of 50,000 riel ($20) per month, Op and his engineer colleagues do not drive trains for the money.

"I could not find the words to describe this job although its becomes my way of life," he said.