Shallow Drilled Braced Monument Overview

Shallow Drilled Braced Monument

Back to comparison table	Mount Commonly Used	Stability	Cost	Install Time	Labor	Substrate	Site Impact
	SCIGN mount	high	$800+	1-3 d	2-3	BR	med

The shallow drilled braced monument (SDBM) consists of 4-5 1"-diameter stainless steel legs in a tripod configuration epoxied into bedrock up to depths of about 5-6 feet. The legs are welded together at the top. Use the SDBM at locations where there is bedrock at or within 0.5m of the surface. Ideal bedrock is fresh or only slightly weathered, and minimally fractured/jointed. If extensive weathering and/or fracturing occur too deep, the bedrock is not suitable for this monument. The SDBM is used throughout the PANGA, BARGEN, and PBO networks.

Site NAMA in Saudi Arabia.

Pros

very stable
materials relatively inexpensive (~$800)
longevity
materials and equipment can be flown to remote locations by helicopter
can be installed in environmentally sensitive sites (small construction footprint)
relatively quick deployment
site permitting potentially easier than for the deep drilled braced monument

Cons

labor and tool intensive
requires competent bedrock at or within 0.5m of the surface
is possibly less stable than the deeply anchored monument
initial cost to purchase required tools potentially expensive

Design and Construction

A heavy-duty hammer drill is required for installation.

Documents

Installation Photos

Installation overview

Approximate Cost

$800 (not including epoxy or cement)

This cost is for the monumentation only; the antenna mount (e.g. SCIGN mount) is not included.

Materials

4 12-foot stainless steel rods (1" diameter) with grooves
3 weld gussets
threaded adapter (if using the SCIGN antenna mount)
epoxy
tubing for delivering epoxy into the holes
welding rod
gas for the generator (if there is no AC hookup)
water (for fire safety while welding)

Tools

AC-powered heavy-duty hammer drill (e.g. Hilti) with drill bits
vacuum/air blower to remove rock flour from drill holes
epoxy gun
air compressor (for the epoxy gun)
generator (if there is no AC hookup)
chop saw or dry cut saw
grinder
vertical and angle level(s)
leg alignment tool or string
welder
file, pick, brush, gloves, helmet, long-sleeved shirt, hat (for welding)
compass

Mount Commonly Used

The SCIGN mount is the antenna mount most commonly used with the shallow drilled braced monument, although it is only required when using the SCIGN radome. Otherwise, any other leveling mount, such as the SECO 2072-series antenna mount, is acceptable.