THE NODDING DONKEYS ARE INDESTRUCTIBLE.

Britain's Passenger Rail operators have wanted to be free of the two-axle Leyland railbuses for years.  "The cars' rough riding properties contributed to the nickname, 'nodding donkeys,' which reflected their design, and the rattling and bouncing could only be augmented by the opposed joints in British track."  Although they've been exiled to the Midlands and points north, they're still moving the people.  "Pacer trains trundle through some of the most beautiful scenery in northern England, across rolling dales and moody moorlands, before pulling up in the great cities of the region: Manchester, Leeds and Sheffield."  Apparently the Midlands are nod-over country.

While some rail enthusiasts retain a certain affection for these unlikely survivors, for people living in the north of England, they've become a symbol of decades of underinvestment in the local transport infrastructure, and of a widening economic north-south divide in the UK.

The complaints are legion. Social media is awash with tales of train roofs leaking, faulty heating and carriages filling up with noxious diesel fumes from the aging engines which power them.

The Pacers are survivors, but they aren't as solid as, say, a Pennsylvania Railroad P70 coach, or the Pullman and Standard arks that served the South Shore Line from 1928 to 1983.

Like the interurban cars, though, the Pacers kept some passenger routes open.  The railbus is the same concept as the doodlebug or rail diesel car in the States.

Despite seemingly widespread dislike for Pacers, rail enthusiasts say that they have actually fulfilled a major purpose.

"Some say that by offering a cheap solution they enabled really small regional branch lines to stay open [in the 1980s] -- that if they had to have really expensive trains, they might have been under greater pressure to close," says Mark ["Man in Seat 61"] Smith.

"At the time there was a threat to rail services and it was said that the Pacers helped to prevent the closures."

"There's also a school of thought that says that some of the Pacers, now that they've been refitted with decent seats rather than bus seats, are actually not that bad and on a line with a decent track even the four-wheel frame isn't that bad," adds Smith.

For many in the north, Pacer trains are indicative of a wider trend, with the region constantly overlooked when it comes to major infrastructure investment. London, which is soon to get an £18.2 billion ($23.7 billion) Crossrail service, always seems to take precedence.

Unfortunately, teething troubles with the new railcars (why is that not a surprise?) might mean the donkeys will continue to nod into the summer.