To start this off, I'd like to hark back [how does one "hark back"? - do you need a special harker with a reverse gear?] to 2010 (in fact I had remembered it as a year or two earlier), when Clive Smithers came to visit me and we spent a couple of days on a very basic Napoleonic siege game, which was a lot of fun, but even at the time very obviously wildly inaccurate.
Once he had returned to Durham, Clive recorded the day on his blog (see here, and a few subsequent posts). I didn't have a blog in those days, though I often wished I did! I have borrowed a couple of his photos from his blog, without permission, alas, but as a taster if you wish to see how far out of our depth we were on that happy occasion.
Early efforts - 2010. On this occasion the fortress sat at one end of my table; I usually place it on a long side now, but since that time I have also rotated the hex-grid markings by 90 degrees, so the orientation of the hexagonal fort in the hex grid is now once again the same as it was in this picture. Plus ça change
At that time, we used wooden blocks from cheap copies of the kids' Jenga game as trenches. In passing, note that the Portuguese troops in the foreground were Clive's, and he had bought them from me a few months earlier; I am pleased to say that these particular chaps are now back in my possession, since I bought them on eBay after the auction of Clive's collection
Our preparation for the 2-day session was that I had bought a ready-painted fort, we pooled all the suitable troops we thought we would need, and the rules were based on a collective speed-read (and very sketchy understanding) of the famous "Sandhurst Game" in the appendix to Chris Duffy's Fire and Stone. One of the huge distortions in our 2010 effort was that we made mining so effective that bombardment of any kind was almost a waste of time. Clive describes this - we had miners digging galleries underground at something close to charge speed, and huge loads of powder being planted under key points with watch-like precision. Very exciting, but bonkers.
So, whatever else I learned from that early session, I came to realise that mining wasn't like what we had thought it might be like. Since then, the topic has always appeared in my sieges as an apologium in the scenario notes - "because the fortress is built on a marsh/next to a lake/on top of a rock, mining is not possible". I have, in fact, swerved it.
Righto. Since I am pleased with the fact that most other aspects of my still-experimental siege rules seem to be working themselves out now, I am honour-bound to revisit these underground efforts. One logical starting place for ideas has to be the appropriate sections of Vauban's Wars, in which the advance of a tunnel is driven by the roll of (yet another) trick die, numbered 0-1-1-2-2-3 (inches), in the mining phase of each turn. Since VW's turns are half a week long, same as mine, it seems it would be simple enough to borrow much of that. However, it might be an idea also to read some material which was not published by Piquet.
So I went again to the obvious place, Duffy's Fire and Stone, and on p.137 he states:
The miners were chosen from among skilled civilian employees of coal or mineral miners. They worked in squads of four or more at a time, one cutting the earth with his pick, one scooping up the spoil and piling it on a wheelbarrow or trolley, one wheeling the container to the entrance of the tunnel, while the fourth dumped the material in a concealed spot. A carpenter and a number of mates saw to the positioning of the frames and the driving of the planks.
Experienced teams of miners and carpenters could progress between fourteen and eighteen feet in twenty-four hours, and could even drive a tight gallery beneath a water-filled ditch.
And then he goes on to discuss the limits to what the diggers could achieve without special arrangements to provide ventilation. It becomes obvious that mining, though it clearly was used, was a very short-ranged weapon, and slow. Clive and I would have been very disappointed with the possibilities back in 2010, and it seems that the best digging possible in Vauban's Wars is still very optimistic.
Let's look at these distances. Duffy's estimated digging rates would work out around 20-25 paces in half a week, which is about 1 inch on my table, or one-seventh of the way across one of my hexes, and this is assuming that the crew have not been interrupted, or frustrated in their efforts by big stones or enemy action.
The history of siege warfare is filled with impressive (and horrifying) extreme examples to distract the reader
[if you are not familiar with the event, check out the mining activities at the siege of Alicante, in 1708-09]. It is as well that we should be aware of such things, but we must also remember that most sieges were not like this - especially in the WSS.
Thus I am coming round to the idea that mining was potentially useful, but should not be contemplated as an attack on a target more than 100 paces away, unless you have no choice, or a few months to devote to the task. Maybe the 3rd Parallel could be a possible kicking off point?
Meanwhile, I am also developing ideas on a workable game system which protects the secrecy of mining and counter-mining without the need for an umpire - thanks to everyone who contributed suggestions - it seems that it is possible, but requires the players to maintain a paper-trail of mining work so that they can prove that they have actually done what they say they have done. I'll discuss this on another occasion.