Tunnelling

[Peaky 556]

Hello Mike, yes two lengths of steel rebar poking out about 3".  The slab thickness varies quite a bit, due to some randomness in my digging and being lazy about going back to fill in and compress some mud in the deeper bits that are only noticed after bashing in the levelling pegs.  It tends to be in the 2.5" to 4" range.

[MikeWilliams]

Thank you.  I'll be digging the ground level part of my line fairly soon an when you work out the quantity of concrete its quite frightening - more than mixing on a board with a shovel as I'd hoped!

Mike

[Peaky 556]

Yes Mike, huge quantities of ballast and cement powder seem to shrink down to concrete that fills next to no space.  I would beg/buy/borrow a mixer if you have more than a few feet to do.  That 11-foot length of my trackbed was filled today, consuming over 10 loads in my mixer.  Cost wise it's not very much, mine was less than about £20 in materials, but still a lot of hard work even with a mixer!  I counted over 200 shovels-full!

[Peaky 556]

Now having a downpour and I'm pleased to say the rain is running away from the tunnel! 

[Peaky 556]

I have decided the wait is long enough and the tunnel portal has started construction with a brick arch, at the near end of that concrete bed you see in the previous photo.  When I have some more ballast (if B&Q is open!) I shall concrete pour and post a photo.

[Peaky 556]

My apologies for the lengthy delays, but my dear wife's projects seem to have risen to the top of the priority list  🤔.  The tunnel is more or less complete, being an 11-yard stretch of curved double track.  It has been successfully commissioned, and I can confirm that radio sets with "cruise control" are necessary, as reception down below is decidedly 'iffy'.
There is only a couple of metres of track laid after this exit, as a braking section before the temporary buffer stops. Overcome with exhuberance on one occasion I entered the tunnel from the other end at high speed, with a couple of coaches in tow.  By the time the loco responded after the 'dead spot', the braking distance was much too short for the speed and load on, and we went clean through the buffer stops  .  The only damage was to the dignity of the driver, who ended up on his head beneath his control panel 

[John Branch]

Tim,
Since the last photo, it seems that a jungle has established itself over the tunnel.  I trust the manhole covers are still accessible?

John

[Peaky 556]

Hi John, yes the manhole covers are still accessible.  I haven't had to lift any since the first run on the outer track, when a stray blob of mortar was discovered obstructing a loco!  So far no tree roots, hedgehogs or gigantic spiders have obstructed any train, but I'd rather any visiting locos are reliable.  I've had one brave chap volunteer with his steam loco, but I'd better get some more track down first.