At least today, the first of three days of strikes by drivers, he knows for certain that he will not be able to reach his office in the capital.

“It is impossible to hold down a job in London from here in these circumstances, and no amount of compensation can make up for that.

“I will take my bitterness to the grave.”

Southern Rail strike causes chaos for hundreds of thousands of passengers

The dispute is over “Driver Only Operation”: whether the driver or the guard opens and closes the doors. Southern wants the driver to push the button on all its trains, rather just some of them. Aslef, the drivers’ union, and the RMT union, mainly representing guards, say this will endanger passengers. They insist the dispute is purely about safety.

“The national loss and disruption must be almost incalculable,” says Mr Swan.

So why has an apparently minor operational issue been allowed to drag on for months? The reason: it is a deeply political dispute that has implications for the nation, with echoes of the miners' strike. As the Government and unions know full well, but are not prepared to acknowledge, the issue is not a “he said/she said” squabble about safety. This is a proxy war about modernisation, being fought out in the commuter belt.

The Government regards the railway as the last bastion of 20th-century trades unionism, and – to the enduring pain of a third of a million commuters – sees Southern as the battleground for rationalising one of Europe's most inefficient railways. Senior politicians believe that improved productivity must be forced through despite the human and economic cost.

UK rail operators ranked Show all 22 1 /22 UK rail operators ranked UK rail operators ranked Grand Central - 79% Here is the list of best and worst train operators with their overall customer score UK rail operators ranked Hull Trains - 73% UK rail operators ranked Merseyrail - 70% UK rail operators ranked Virgin Trains West Coast - 69% UK rail operators ranked C2C - 62% UK rail operators ranked East Coast/Virgin Trains East Coast - 61% UK rail operators ranked Chiltern Railways - 60% UK rail operators ranked Scotrail - 59% OLYMPUS DIGITAL CAMERA UK rail operators ranked East Midlands Trains - 58% UK rail operators ranked London Overground - 56% UK rail operators ranked Cross Country Trains - 55% UK rail operators ranked First TransPennine Express - 55% UK rail operators ranked London Midland - 55% UK rail operators ranked TfL Rail - 52% UK rail operators ranked South West Trains - 51% UK rail operators ranked First Great Western/Great Western Railway- 50% UK rail operators ranked Northern Rail - 50% Phil Sangwell UK rail operators ranked Arriva Trains Wales - 49% UK rail operators ranked Southern - 48% UK rail operators ranked Abellio Greater Anglia - 47% UK rail operators ranked Southeastern - 46% UK rail operators ranked Thameslink and Great Northern - 46%

The unions, meanwhile, are playing the safety card for all it is worth rather than acknowledging their real concerns: that hard-won employment conditions will be eroded and that their power will be weakened.

That is why commuters such as Bill Swan face much more disruption in the coming weeks. They believe that the dispute will drag on for many more months, and that only when it is resolved will GTR be stripped of its franchise, having taken the heat for the Government’s strategy.

After the drivers strike on Tuesday, Wednesday and Friday this week, it is the turn of Southern guards. RMT members will stop work on Monday 19 and Tuesday 20 December, with a four-day strike across the New Year from Saturday 31 December to Tuesday 2 January. Drivers will then strike for most of the second week of the New Year: Monday 9 to Saturday 14 January.

A glimpse at Aslef's Conditions of Service – Southern Drivers, published four years ago, reveals that staff are still working according to rules agreed in the early 20th century. A dispute about the rosters at the Three Bridges depot in Sussex turns on regulations from 1928, an era when steam traction prevailed. The document also goes into considerable detail about Driver Only Operation (DOO) of trains, first agreed nationally in 1985.

Some of the arrangements on the practice agreed between the union and the management look almost comical: “If the conductor is left behind by driver error, the duty may run DOO until the conductor can be reunited with the service.” But the document demonstrates that the practice at the heart of the dispute has been running safely for decades.

While the union’s quaint name – the Associated Society of Locomotive Engineers and Firemen – endures, society and technology have moved on. But the railways, in general, have not.

Trains across the country run on Sundays only because staff work overtime. In a seven-day-a-week nation, relying upon staff working above their stipulated hours to run a railway is no way to, well, run a railway.

Britain’s trains devour billions in taxpayer subsidies, while at the same time aggrieved peak-hour travellers complain they are spending a fortune on tickets. But not today. Conditions of Service – Southern Drivers prescribes the walking time from the crew room at Victoria to the platform as 10 minutes. This morning, it would have been a more lonely walk.