Monday, January 02, 2012

Rock drill

From: "Bill Oudegeest"

I am working on some articles about the CPRR particularly Tunnel 6, the San Mateo (first locomotive over the Summit), the Sacramento (the engine for the shaft house), etc.

I would like to locate a star drill bit such as used by the Chinese to bore holes for black powder while building the Sierra tunnels.

Does anyone have any where I can look? ...

—Bill Oudegeest, Donner Summit Historical Society, Donner Summit, CA


Anonymous Anonymous said...

I am not aware of any "star drill" instruments used on the CPRR during construction. The only relics that I have seen are all the flat chisel type; these can be found along the old grade from time to time, usually broken or totally worn.
G J Chris Graves, NewCastle

1/05/2012 3:53 PM  
Blogger CPRR Discussion Group said...

From: "Kyle K. Wyatt"

The California State Railroad Museum has a nice long drill bit, with star end, on display in the Chinese exhibit in the Transcontinental Gallery. There has been ongoing discussion about whether it is a hand drill, or if it was for a machine. I don't have a conclusive answer (and would welcome comments), but I observe that the drill steel does not have a lubrication hole in the center (as I would expect if it was for a machine), so my suspicion is that it is a hand drill. The bit is about the right diameter for black powder (2" - 2 1/2").

The best Central Pacific photo of drill steel is Hart 119 showing a group of Chinese workers outside Summit Tunnel, with drilling equipment. A nice copy is available from the Library of Congress.

On the Union Pacific there is a nice closeup of a driller and his shaker with drill in hand.


1/07/2012 10:19 AM  

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