Tunnel construction

I did not write a post this weekend as I had no update other than to say that phase 1 is complete and trains are running. The remaining track arrived on Friday as expected and I put it in place on Saturday morning. After a couple hours spent on ballasting and cleaning I had trains up and running by Saturday afternoon. My BN consist, still with mismatched couplers, had no issues staying together and managing the curves. And I forgot to take pictures!

So this week attention turns back to phase 2 construction. In the last post I mentioned finalizing tunnel alignment. Once I had the exact location determined, I put down 3/4" gravel and tamped it down to form an even foundation, then put the bottom row of bricks in place, also using the 8" bricks as spacers as they are the width of the tunnel.


The last few days I've been working on a portal for each end of the tunnel. The last blog post showed a drawing of the south portal on XPS (extruded polystyrene) prior to any cutting and carving. And here is a picture of those portal pieces carved, cut, sanded and ready for their first coat of paint


Here the finished pieces are shown as they'll appear at the south portal. I'm very happy with how these have turned out. I used the method described by Mike McLaughlin of the Mt. Meterbox and Bare Sands Railroad. His video on YouTube provides step-by-step instructions; click here to see it.


Using the portal pieces as guides, I placed bricks behind them then used stakes to hold the bricks in place.


Now for the fun part...building a masonry tunnel. I've never laid bricks before and I'm sure my resulting effort would never pass a home inspection, but fortunately I'm not worried about holding up the foundation of a house. After the third layer of bricks I stopped to check for alignment and ensured everything was still level.


After the fifth layer of bricks I stopped to clean the tunnel interior of mortar than had fallen in. I then put down a layer of 1/4-minus and tamped it into place. My 8" tamper fit perfectly within my 8" tunnel walls as planned.


For the roof I decided on 2" concrete blocks. I bought these at Home Depot because they were labeled as 8" x 16" which fit the dimensions of my tunnel perfectly. But I never measured the blocks so I didn't realize that neither of those dimensions were correct until I started putting them into place. My mistake.


As the concrete blocks were less than 8" wide, I now had a roof gap at the north end of the tunnel of about 2". So as a workaround I turned two bricks on their sides and put some mortar between. Unfortunately this will now be a little taller than the portal I created, so I'm not sure how I will hide it. I might paint the brick to match my portal. Or if it doesn't look good I may knock it out and try something different.


The tunnel now needs to sit for two days to allow the mortar to cure before I start burying it and landscaping around it. I'll also put track down through the tunnel once it arrives this week.

After all this work I still have a big pile of bricks! What will I build next?