Table d 1 shows the approximate weight necessary to

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ainer and the gross weight of the container and its contents. Planners find this calculation useful for designing anchors, but it should not be relied upon for actual emplacement. To avoid hurried improvisation during emplacement, emplacers should always test buoyancy in advance by actually submerging the weighted container. This test determines only that a submerged cache will not float to the surface. Emplacers may need to attach additional weight to keep the container from drifting along the bottom. As a rule, the emplacer should add at least 1/10th of the gross weight required to sink the container and even more weight if strong currents exist in the area. Submersion Depth D-98. Planners must first determine the submersion depth of the container to calculate the water pressure that the container must withstand. The greater the depth, the greater the danger that water pressure will crush the container. For instance, the standard stainless steel burial container buckles at a depth of approximately 4.3 meters. The difficulty of waterproofing also increases with depth. Thus, planners should only use the minimum depth necessary to avoid detection. Generally, 2.2 meters is the maximum advisable depth for caching. If seasonal or tidal variations in the water level require deeper submersion, planners should test the container by actual submersion at the maximum depth it must withstand. Depth of the Water D-99. Emplacers must accurately measure the water depth at the emplacement point. If planners design the cache to rest on the water bottom, this depth is the same as the submersion depth. Planners may design the container for suspension some distance above the bottom, but the emplacer must know the depth of the water to determine the length of moorings connecting the container to the anchors. High- and Low-Water Marks D-100. Emplacers must estimate any tidal or seasonal changes in the depth of the water as accurately as possible. They must consider the low-water mark to ensure that low water will not expose the cache. D-16 TC 1...
View Full Document

This document was uploaded on 01/15/2014.

Ask a homework question - tutors are online