## 3 Materials and Methods
### Design of Experiments  
Several experiments were developed to gain insight into the performance potential of the RAATM's anchoring function (anchoring strength) and the influence of the wire root array on anchoring strength by assessing the capability of the anchoring portion only (the wire roots and anchor spike components of the anchor assembly) to hold fast in various sediments when under tension. Toward this end, the authors sought to answer three primary research questions:  
1. What effect does sediment type have on anchoring strength?
2. What effect does increasing the number of wire roots in the array have on anchoring strength?
3. What effect does combining the wire root array with the anchor spike have on the mechanism's ability to resist angled loads?  
An experiment was designed for each research question, and a simple prototype of the lower portion of the anchor assembly (a partial anchor plug, an anchor spike, and a wire root array) was constructed. The construction of this prototype is discussed in Section 3.5. Three distinct types of sediments were collected from the local environment to test the anchoring strength of the assembly. The goal was to achieve the best possible representative sampling of possible seabed conditions (capable of penetration). The collection of sediments used is discussed in Section 3.6. The procedure for each experiment is discussed in Section 3.7, and the results are discussed in Section 4.  
The first experiment was designed to answer the first research question by collecting data samples for anchor line tension (force) at the point of uprooting (hereafter referred to as anchoring strength) using the prototype. To test the correlation between sediment type and anchor strength, three distinct types of sediments with differing particle sizes were collected, with the prediction that smaller-particle-size sediment conditions would yield higher anchoring strength. The experimental null hypothesis, therefore, was that sediment type has no effect on anchoring strength. Three data cells consisting of 30 individual tests of anchor strength (hereafter referred to as \"pulls\") were collected for each of the three sediment conditions in Test 1 for comparative statistical analysisThe second experiment was designed to answer the second research question by collecting anchoring strength data for the three sediment conditions using three configurations, under vertical loads, in order to understand the relative contribution of the number of wire roots in the array to the overall anchoring strength. The full array of eight wire roots was used for Test 1 of the first experiment. A partial array of four wire roots (Test 2) and no array at all (Test 3) were used for data collection in Experiment 2. The experimental null hypotheses were: the mean anchoring strength for each configuration is equal (H01), the mean anchoring strength for each condition is equal (H02), and there are no interactions between the factors (H03). Thus, nine data cells consisting of 30 pulls each were collected in Tests 1-3 for comparative statistical analysis.  
Finally, the third experiment was designed to answer the third question by collecting anchoring strength data for the three sediment conditions using two anchor configurations--the full array of eight wire roots (Test 4) and no array at all (Test 5)--under angled loads, in order to understand the contribution of the full wire root array to resisting angled loads. The prediction was that the wire root array would aid the mechanism in resisting angled loads, with the corresponding null hypothesis that the wire root array would have no effect on resisting angled loads. Due to time and logistics constraints, ten pulls were conducted for each condition and configuration. The collected data were sufficient, however, for the comparative statistical analysis.