Well, I now have a short trench lined with weed control fabric and filled with 10mm gravel plus a brick.

Behold, I am the natural heir to Capability Brown.

Of course, my gang of crack navvies immediately commenced shovelling the gravel into small buckets and standing on the side of the trench to see if it would collapse (it did).

The materials came from that well-known emporium of disappointment and specialist non-suppliers of the exact thing you want, B&Q. In a horrendous misjudgement sure to be corrected next time they restock, they accidentally had all the items I wanted. At least, if I went to my local store and the one near work. The bricks in particular were a steal at 4p off the RRP, mainly because to the poor plebs on the tills, one unmarked brick looks pretty much like another when you’re trying to find it in the price list. Bargain! I should have tried the builders merchants down the road instead of supporting another generally useless conglomerate, but I couldn’t face the “where’s the site the lorry is delivering the pallets to? what do you mean ‘a small railway’?? how small?” conversation when I was only after single numbers.

What this exercise has shown:

• If I dig the trench this deep, it will require approx. 1 bag of gravel per 4 ft of trench, or 13 bags all round. Not extortionate, but a lot of lifting. I’m sure I can get away with a shallower trench.
• It’s easy to get the brick level. It’s also easy to knock it out of true again.
• I don’t yet have a good solution for the edge of the fabric. A minor cosmetic detail (dear)!

Not sure how much further I can go with this without some track to lay, as it will help to keep the course straight, place the bricks at the right intervals and demonstrate how stable the trackbed is likely to prove. But I hesitate; a couple of bricks and bags of gravel are a minor flutter that can be written off later as an unfortunate error of judgement, but a dozen lengths of SM-32 represent a Significant Investment from which there can be No Going Back. And there are all these bills this month too…