I agree that it's a moot point, but why could there not have been cribbing between the platforms (if these existed) before the space between them was filled in with soil? I appreciate the difficulty of removing the cribbing from the bottom up, but what if it was designed that way when the cribbing was introduced? So, surely, someone could have dug such a shaft to 110 feet before 1803.
R.V. Harris reports that a water bearing tunnel entering the pit excavations was recorded by two different operators at much the same depth (about 110 feet) both of whom agreed that it was well cut, man-made, and measured 4 feet by 2.5 feet. One report said that it was angled at 22.5 degrees (presumably upwards). Furthermore, the subsequent activities of each group were based on the existence of this tunnel, that is, they actually acted upon it as being fact and spent considerable time and money trying to block off the tunnel they'd encountered and thereby stop the flow of water.
It's all very well for some to declare that these people must have been lying, because of Dunfield's observations, but as far as I'm aware Dunfield didn't actually say that his observations proved that there was never a water bearing tunnel, just that he didn't see one. Could such a tunnel have collapsed?
From my research, the process of cribbing used at the time is as follows...
Method 1: You dig a hole and stack prefabricated frames the size of the shaft on top of each other.
As digging continues, the cribbing keeps moving down and a new prefabricated frame is placed on top.
Method 2: Another method used...after digging a hole, precut logs were lowered down and the frame is built in the bottom of the shaft, and stacked on top of each other before they are pinned in place. They continued digging down, framed the next section and pinned it in place.
Platforms for both methods were attached inside the cribbing to allow largest possible opening to traverse the shaft and lift and lower buckets.
In both cases, the weight of the cribbing rests on top of each other making difficult to remove from the bottom up. So if someone wanted to hide their shaft they'd remove the top 10 or 20ft, lay a platform across the top and fill with dirt. They would never think about removing the cribbing because of danger and effort envolved.
This is the same method used by Chappels shaft shown in the picture i attach earlier in this thread.
Could someone have used another method? Maybe.
Lets suppose they dug down 10ft and laid a platform into the sides of the hole and then cribbed the sides resting on the platform. This would imply the platform covers the entire hole, so how would they get below the platform to dig deeper.
I guess you'd have to cut an opening in the middle.
Since the shaft was 12ft in diameter, how big can you make the hole. 3ft, 4ft square?
A bigger hole means you need to re-enforce the platforms.
So lets say they did this. its a lot of effort and danger to remove the wall cribbing and replacing cut logs for the opening with full logs.
Ive never cribbed a shaft and i had a hard time finding out how they cribbed before 1800 so if some knows more or finds my description wrong, you will in no way hurt my feelings.
With regards to the 4x2.5 tunnel, i don't know but i can only make one comment...they used cribbing to get down there to find it.
One last thought...how did dan blankenship stack those tanker cars when he dug 10X? I think Method 1 was used.
Maybe Old Sage can tell us since spoke to dan.