Tumwater Hill
Tumwater Hill (TWHL) site is located on Tumwater Hill, Tumwater, Washington.
The city of Tumwater provided permission to install a continously operating site near the Tumwater elementary school.
With help from SCIGN and UNAVCO, we installed a smaller, hand-drilled geodetic
monument, known as the short drilled-braced geodetic monument. The monument
design is perfect for rapid installations of continuous GPS sites.
KTBW is part of a radio telemetry (FreeWave) subnetwork that feeds into the Pierce
College hub. It is also used as a rely for other sites within the subnetwork.
Click here to
see a map of the subnetwork.
The monument consists of 1-inch diameter stainless-steel rods forming a quad-pol that stands about 3
feet above the ground surface and is anchored 3 to 6 feet into bedrock. A generator-
powered handhelp rotary drill using a 1.5-inch diameter drill bit is used to prepare
the holes. Epoxy is used to anchor the stainless-steel rod in the holes.
