The cabin, is compact, in every way. Every inch, accounted for. Every component, slotted in, perfectly. And, with full rucksack and boots and spare boots and string bag, a bit of a squash to get in too. Once you're in though, once you've sorted, and stowed, and made things neat, any claustrophobic feelings will just, well, have magically evaporated. In some curious way, these cabins can somehow, surreptitiously, expand. 
As the train pulls out of Penzance station, you begin to hear the rumble. A sturdy, rounded edges sort of rumble, a cacophony, of gently juddering low frequency vibrations, that'll sway about beneath you and your bunk as the miles pass, and gradually become your friend. The sound is, dark, and velvety, and when combined with the physical sensation of being horizontal on a cotton soft pillow, deliciously soporific. 
And there are the other swaying sounds. The tiny creaky movements of all the cabin's fittings. The muffled clunks and clicks, as someone sleepily feels for the night light switch. And The carriage's squeaky suspension,  that in your dreams can be a swinging sign, outside some windswept Out West saloon. Howdy friend, welcome to the Old Railroad. Care to come in?
But best of all, to us, perhaps to all who slumber their nocturnal way cross country aboard the Night Riviera, is the ever-present, ever fluctuating, omnipotent hum of the locomotive. The giant sized engine, the dynamo, the journey's conductor, that valiantly leads the way into the night, and makes the whole thing happen. And keeps it happening, warmly, and reassuringly, over hundreds and hundreds of dark, dark miles.
* This spatial sound photograph, an unbroken sixty minute segment of the journey from Penzance to London Paddington, was taken from within the cabin beside the bunk. It will to those trigger deep and we hope blissful memories of travelling through the night on a sleeper train. If you haven't done this yet, we hope this recording conveys at least some of the unique and soporific sound experience of a night train sleeper.