“Big Block” mine portal, Luzerne County, Pennsylvania

October 2024

Gate Type: CUPOLA

For the third year of our five-year Pennsylvania Bat Gate Workshop series, we returned to another gaping opening near our 2023 gate. This one was messy, as we had to cut out a deadfall, and remove a lot of rocks, roots, and rotten logs. But once past the duckunder entrance, it lead to hundreds of feel of very large mine passage. To prevent organic debris buildup again, and to provide bats maximum flight space out of the steep entrance and around the namesake big block of sandstone nearby, we designed this clever cupola to enclose the maximum amount of space around the entrance area. The team worked extremely well to bring it all together, resulting in a very fine product. All photos © Jim Kennedy except finished photo, © John Chenger.

Here is the portal as we found it. How and where would you attach a gate to this mess?
The local PGC guys have have been an enormous help on these workshops, but they are usually up by the cutting station and not at the portal. Here, they come over to “supervise.”
You get an ideal of how we had to clean down to bedrock in this photo, in order to anchor the gate securely.
Miguel is welding hangers on the 6″x6″ angle corner columns. We used the inverted corner design due to the tight constraints of the work area.
The cupola frame is slowly taking shape. We purposely designed it to be anchored to the namesake big block, as well as the mouth of the portal.
A quick look inside the mine shows some rotting and collapsing roof supports, illustrating the hazardous nature of these openings and one reason they are gated.
We get an almost aerial shot of the gate when up on the big block. It’s shaping up nicely.
Small, odd-shaped gaps that could be exploited by potential vandals are secured with angle and covered with rocks.
We left the front bars until last, to facilitate our movement. Now that they are in, it’s time to install the top.
The top nears completion, and equipment no longer needed is ferried back to the trucks up above the cliffline.